Star Bugs

A pretty special damselfly—Pseudolestes mirabilis Kirby, 1900

(©Xin Yu, permitted to use)

1. Species information

Scientific name: Pseudolestes mirabilis
General name: Phoenix
Classification: Insecta -> Odonata -> Pseudolestidae -> Zygoptera -> Pseudolestes
Habitat: Adults can be found in most areas in Hainan, in the small to moderate-sized stream in well-forested uplands; and also sometimes encountered in more open habitat; Larvae were found in both shady and open montane streams with stony substrates. Some even occurred in very small “puddles” covered with dense vegetation formed by discontinuous streams.
Distribution: Hainan, China (endemic)

(Zhu et al., 2015; permitted to use)

Figure 1. (A) Map of the occurrence records of P. mirabilis in Hainan Island. (B) Adult, (C) larva and (D) habitat. (Zhu et al., 2015; permitted to use)

Description: the adult is fairly small. Males have a blue face, black-brown eyes, and black head. The thorax is matt black. The forewing is long and narrow; the hind wings are much shorter and broader. The hind wings are black on the dorsal surface, with an extensive metallic gold. The hind wings underside is black, too, marked extensively with white from the nodus to the tip. Females lack the blue face and have more extensive yellow streaking on the thorax. The hindwing is black on the distal half, tipped with white (Kirby, 1900; Reel & Zhang, 2015).

Figure 2. Adult of P. mirabilis (©Xin Yu, permitted to use)

The larva is robust with a large head and small, relatively broad and robust thorax. Legs moderately short and strong, bearing scattered short spines and hairs, lacking bands or other marks. A tuft of abdominal gills is present ventrally on the final segment, the gills are paired and retractable. Cerci wholly concealed by expanded gill tufts in ventral view. Inflated sack-like caudal gills covered in short, stout setae; football-like in the final larva with blunt apical projections, slightly longer and finger-like in the earlier instar larva. Ground colour of body dark brown, lacking distinct bands or marks. (Yu & Bu, 2011; Yu & Bu, 2014).

Figure 3. (A) Dorsal and (B) ventral view of larvae of P. mirabilis (©Xin Yu, permitted to use)

Figure 4. (A) Alive larvae and (B) the young adult after eclosion (©Xin Yu, permitted to use)

After a boring and prim introduction of this species, let’s start the really interesting and exciting part!

What is P. mirabilis ?

P. mirabilis is remarkable as its beautiful morphology: blue face, black-gold hindwing and the beautiful ‘dance’. That’s the reason they are called as ‘Phoenix’. You can easily find this species in streams in Hainan Island, many literature and books said as ‘very widespread’ or ‘common’. However, the use of ‘common’ is a little bit misleading, because this kind of ‘common’ is limited in Hainan Island.

Longely species

Actually, P. mirabilis should be called as ‘very endemic’ or ‘very unique’. That is not only because of that this species is only distributed in Hainan Island, but because of its unique status in classification. For a long time, P. mirabilis is like a waif: it has no relative and has no idea about its own position in phylogeny. From 1900 to 2010, its classification position has changed many times. But finally, with the help of molecular data, the phylogenetic study suggested that it should go back to its own family (Dijkstra et al, 2014). What does it mean? It means that P. mirabilis finally finds its family, BUT this family only has one species, no other sisters or we have no idea about where its sisters are yet. It’s not normal in insects, which always has a lot of species in a family level group. Another significant character that helps it find its own family is its retractable gills. The Odonata abdominal gills only occur in larvae of Amphipterygidae, Euphaeidae and Polythoridae (Corbet, 1999; Sisby, 2001) and believed as a homologous organ which evolved independently (Yu & Bu, 2011; Yu & Bu, 2014).

It is a very special phenomenon in studies of Odonata that using overall larval characters to study about taxonomy and phylogeny. Some species like this one we are discussing, P. mirabilis, the characters of its adult may simply be the result of a rapid evolution and adaptation (Yu & Bu, 2011). Therefore, it is hard to place this kind of monotypic genus by analysis adult characters, even under a comprehensive molecular study (Bybee et al., 2008; Dijkstra et al., 2014; Wang et al., 2017). On the other hand, the larval characters may often be less affected by the radiation or adaptation than the adult. So the larvae of Odonata play important and unique roles in both taxonomy and phylogeny studies, which is very different to find in other insect groups.

Special ‘scales’ in hindwings

One more thing in morphology that makes P. mirabilis very unique is the special ‘scales’ in its hind wings. It’s a truth that the hind wings of many dragonflies could reflect beautiful colour. The reason why they could do it is that of the multilayer interference or caused by wing-membrane pigmentation (Prum et al., 2005; Schultz & Fincke, 2009; Nixon et al., 2017). P. mirabilis reflects brilliant white on the ventral side of its hindwings and a copper-gold colour on the dorsal side. Different with other Odonata wings, the whiteness on the wings of P. mirabilis results from light scattered by a specialized arrangement of flattened waxy fibres and the copper-gold colour is produced by pigment-based filtering of this light scatter (Nixon et al., 2017).

Beautiful ‘dancing’

The structure is the basis of behaviour. Since P. mirabilis has such special morphological characters, it may be related to its unique (if it has) behaviour. Actually, the answer is YES! There are more females than males in populations of P. mirabilis (Cordero–Rivera & Zhang, 2018), which means a war to compete for mates between males is inevitable. How damselfly fight? Two periods. The first period is flaunting, the exhibition of the coloured hindwings. The agonistic encounters between males were usually very short (less than 2 min) and consisted of a face–to–face display with both males maintaining a close distance while flying using only the forewings. It should be noted that NO other Odonata flies with only two wings in territorial contests. Furthermore, a small proportion of fights were escalated and lasted about one hour (Cordero–Rivera & Zhang, 2018). Let’s back to the structure of its hind wings, this structure provides a mechanism enabling P. mirabilis to display its bright wing colours efficiently for territorial signaling, both passively while perched, in which the sunlit copper-gold upperside is presented against a highly contrasting background of foliage, and actively in territorial contests in which the white underside is also presented (Nixon et al., 2017). Therefore, the intrasexual selection is behind the evolution of coloured wings in this species (Cordero–Rivera & Zhang, 2018).

The second period of competition is in population. Most of Odonata males will translocate sperm to their vesicle before each mating, but obviously, so far our P. mirabilis doesn’t want to be such normal. Males of P. mirabilis translocate sperm after copulation a behaviour that cannot be easily explained (Cordero–Rivera & Zhang, 2018).

‘Common’ or ‘rare’?

I really do not want to use ‘special’ to describe this species again since I have used too many times. I believe you could understand how important this species is. When people said it is a common or widespread species, does it mean this is safe under the crazy anthropic activities? Especially in Hainan Island, where there is a large number of estate development and tourism have swallowed quickly a large area of forests. In IUCN, the information of this species is DD (Data Deficient). Recently, couples of studies have done its distribution and population genetics (Zhu et al., 2015; Xue et al., 2017). The results indicated that P. mirabilis experienced significant genetic drift recently (last glaciation of Pleistocene), and since its population has a low genetic diversity. What it means? A high genetic diversity is a key to adapt or fight with the terrible environment, it allows your population carrying enough mutation to face to the environmental changes. Even there are several individuals that carrying the beneficial mutation, these mutations will disperse quickly in their population. That is the power of natural selection. That is also the reason why passenger pigeon extinct: whatever how large of your population or abundance, you cannot escape from this fast and strong selection which accompanied by a rapid loss of most mutations (Murray et al., 2017). Back to our P. mirabilis, the low genetic diversity also means that it has a low adaptive capacity to the environment, and could easily be suffered from surrounding disturbance (climate or human impact, whatever).

Figure 5. Historical demography inferred from mtDNA COI sequences in Bayesian skyline plots analysis. P. mirabilis experienced significant genetic drift recently. (Xue et al., 2017; permitted to use)

These studies also pointed out that some marginal small populations (such as several on the east coast) are already dying out. The relatively high population size and genetic diversity of the south-central population are under serious threat from tourism and urbanization, if not protection from rapid extinction.

Figure 6. (A) Estimations of gene flow for all populations implemented, arrows represent the direction, the green arrow means high gene flow. Circular dots indicate different populations and the different colour in dots represents different haplotypes. We could find that the population 6 in the eastern margin has a very low genetic diversity. (B) Predicted species distributions under current conditions. We could find that the centre of diversity is located in these regions that under serious threat from tourism and urbanization. (Xue et al., 2017; permitted to use)

References

Bybee, S. M., Ogden, T. H., Branham, M. A., & Whiting, M. F. (2008). Molecules, morphology and fossils: a comprehensive approach to Odonate phylogeny and the evolution of the Odonate wing. Cladistics, 24(4), 477-514.
Cordero–Rivera, A., & Zhang, H. (2018). Ethological uniqueness of a damselfly with no near relatives: the relevance of behaviour as part of biodiversity. Animal Biodiversity and Conservation, 41(1), 161-174.
DijkstraI, K. D. B., Kalkman, V. J., Dow, R. A., Stokvis, F. R., & Van Tol, J. A. N. 2014. Redefining the damselfly families: a comprehensive molecular phylogeny of Zygoptera (Odonata). Systematic Entomology, 39(1), 68-96.
Kirby, W. F. 1900. LXX.—On a small collection of Odonata (dragonflies) from Hainan, collected by the late John Whitehead. Journal of Natural History, 5(30), 530-539.
Murray, G. G., Soares, A. E., Novak, B. J., Schaefer, N. K., Cahill, J. A., Baker, A. J., … & Gilbert, M. T. P. (2017). Natural selection shaped the rise and fall of passenger pigeon genomic diversity. Science, 358(6365), 951-954.
Nixon, M. R., Orr, A. G., & Vukusic, P. (2017). Covert linear polarization signatures from brilliant white two-dimensional disordered wing structures of the phoenix damselfly. Journal of the Royal Society Interface, 14(130), 20170036.
Prum, R. O., Cole, J. A., & Torres, R. H. (2004). Blue integumentary structural colours in dragonflies (Odonata) are not produced by incoherent Tyndall scattering. Journal of Experimental Biology, 207(22), 3999-4009.
Reels, G. T., & Zhang, H. M. 2015. A field guide to the dragonflies of Hainan. Kadoorie Conservation China, Kadoorie Farm and Botanic Garden (eds). Joy of Nature–Hainan Wildlife Field Guide Series. Beijing.
Schultz, T. D., & Fincke, O. M. (2009). Structural colours create a flashing cue for sexual recognition and male quality in a Neotropical giant damselfly. Functional Ecology, 23(4), 724-732.
Wang, R., Yu, X., Xue, J., & Ning, X. (2017). Descriptions of larvae of Vestalaria venusta (Hämäläinen, 2004) and Matrona basilaris Selys, 1853 (Odonata: Calopterygidae). Zootaxa, 4306(4), 580-592.
Xue, J., Yu, X., Zhang, H., Chen, X., & Bu, W. (2017). Population genetics and ecological niche modeling shed light on conservation of the island endemic damselfly Pseudolestes mirabilis (Odonata, Pseudolestidae). Hydrobiologia, 790(1), 273-286.
Yu, X., & Bu, W. 2011. A description of the remarkable larva of Pseudolestes mirabilis Kirby (Odonata: Pseudolestidae). International Journal of Odonatology, 14(2), 105-110.
Yu, X., & Bu, W. 2014. Notes on the retractabilty of gill tufts in Pseudolestes mirabilis (Zygoptera: Pseudolestidae). International Journal of Odonatology, 17(2-3), 123-126.
Zhu, G., Yu, X., & Bu, W. 2015. Ecology and conservation of Pseudolestes mirabilis (Odonata: Zygoptera), a damselfly endemic to Hainan Island of China. Entomological Science, 18(1), 123-129.

Lovely but Tricky – Ant-mimicking Jumping Spider Myrmarachne magna

Author: Dexter Cheng Kwan Ho

Speaking of spider, the first thing comes to your mind is probably the hairy, scary and evil-looking tarantula. In fact, the large and lethal spiders only comprise a tiny portion of the list of spider species. The largest family of spider is actually the lovable and kind-looking Salticidae, also known as jumping spider^1,2. Salticids are usually distinguished by their tiny size, a pair of conspicuously large anterior middle eyes (out of the eight eyes they have), and of course, their capacity of jumping.

There is one thing very peculiar about salticidae, they are mimicking expert, especially in ant-mimicking. For example, Myrmarachne magna is a species of ant-mimicking jumping spider that are commonly found in Taiwan, Hong Kong and nearby region. The name M. magna was coined and described by Saburo Saito in 1933³. The genus name Myrmarachne comes from “myrmex” and “arachne” which means ants and spiders in Ancient Greek respectively.

Notably large anterior middle eyes of M. magna with raised first pair of legs, imitating the antenna of ants

Photo credits: https://www.flickr.com/photos/awei750/41474895521/

M. magna belongs to order Araneae, like other spider relatives in this order, M. magna has two tagmata (body parts), namely cephalothorax and abdomen. In order to mimic ants, which have three tagmata (head, thorax and abdomen), the chelicerae, also referred as their “jaws”, of M. magna is enlarged to mimic the third tagma³. Besides, when compared to non-ant-mimicking jumping spiders, ant-mimicking jumping spiders have long and thin legs similar to ants, rather than short and robust legs which are commonly found on other spider species⁴. But the trick is not convincing enough for the keen eyes in the wild. How can an 8-legged creature acts like a 6-legged one? M. magna figured out their way, by waving the foremost pair of legs in the air, pretending the antennae of the ants! At last, M. magna successfully disguises as ants, but now what? What are the advantages of the mimicry?

Many studies showed that ant-mimicry brings benefits to the jumping spiders, mainly by increasing their survival rate in the nature^5,6,7. Although jumping spider has the best vision compared with other animals with similar size⁸, this does not keep them away from all kinds danger. Moreover, jumping spiders do not have strong body armor, fancy chemical defense and enormous jaws to protect themselves like other arthropods do⁷. Mimicking ants can disfavor other diurnal insectivores such as birds, reptiles, amphibians and even other jumping spiders, as ants are well-known as a “bad meal” for other predators because of their social behavior, powerful mandibles, hard spines, unpalatable taste, chemical spray and stinger in some species⁶. As a result, ant-mimicking lowers the attacked rate of jumping spiders⁷.

The species in this genus Myrmarachne prey on wide range of arthropods, study shows that they also tend to eat eggs of other spiders⁹. Experiments are carried out to show that when a spider encounters an ant, the probability of the spiders to abandon their eggs and web is higher than when the spider encounter another spider¹⁰. It is possible that M. magna not only gain protection from ant-mimicry, but also extra food source.

But there is no perfect escape route. Even the morphology of M. magna confuses many predators and preys, still, they cannot confuse the ants. Ants are experts in chemoreception, many information can be extracted through a single touch of their sensitive antenna. Sometimes encounters between M. magna and ants are unavoidable and researchers¹¹ found that the result of the encounter is determined by which parts of the body is contacted between the ant-mimicking jumping spider and the ant. In most of the cases, the form of the contact will be made between the first pair of legs of the spider and the antennae of the ant. This will usually result in the retreat of the spider. It is because ants will usually actively show aggression toward the opponent once the ants sense that the opponent is not their nestmate though chemoreception¹². So, the right decision for the spider is to retreat without hesitation.

Normally, salticidae mainly prey on other small arthropods, even fast-moving flies are on their menu. In China and Taiwan, jumping spiders are also called “flies-tiger” according to their diet preference. They are able to leap and catch their prey aided by their excellent sight and precise landing, even if they fail to land on target, they always attach themselves with their starting point by a thin tread of silk produced at the end of the abdomen, similar to a “safety rope”. Other than leaping, researchers have discovered that ant-mimicking jumping spiders prefer lunging to their prey⁹.

Next time when you are walking in the wood, seeing a strange-looking ant, make sure to check if it is an ant-mimicking jumping spider and spend some time to observe the fascinating example of mimicry!

Reference:

Peng Xian-Jin, Tso I-Min & Li Shu-Qiang (2002). Five New and Four Newly Recorded Species of Jumping Spiders from Taiwan (Araneae: Salticidae). Zoological Studies. 41 (1), 1–12.
Coddington, J. A., & Levi, H. W. (1991). Systematics and evolution of spiders (Araneae). Annual review of ecology and systematics, 22(1), 565-592.
Saito S. (1933). Notes on the spiders from Formosa. Transactions of the Sapporo natural History Society, 13(40), 32-61.
Cushing, P. E. (1997). Myrmecomorphy and myrmecophily in spiders: a review. Florida Entomologist, 165-193.
Nelson, X. J., Jackson, R. R., Edwards, G. B., & Barrion, A. T. (2005). Living with the enemy: jumping spiders that mimic weaver ants. Journal of Arachnology, 33(3), 813-819.
Cushing, P. E. (1997). Myrmecomorphy and myrmecophily in spiders: a review. Florida Entomologist, 165-193.
Huang, J. N., Cheng, R. C., Li, D., & Tso, I. M. (2011). Salticid predation as one potential driving force of ant mimicry in jumping spiders. Proceedings of the Royal Society of London B: Biological Sciences, 278(1710), 1356-1364.
Blest, A. D., O’Carroll, D. C., & Carter, M. (1990). Comparative ultrastructure of Layer I receptor mosaics in principal eyes of jumping spiders: the evolution of regular arrays of light guides. Cell and tissue research, 262(3), 445-460.
Jackson, R. R., & Willey, M. B. (1994). The comparative study of the predatory behaviour of Myrmarachne, ant‐like jumping spiders (Araneae: Salticidae). Zoological Journal of the Linnean Society, 110(1), 77-102.
Nelson, X. J., & Jackson, R. R. (2009). Aggressive use of Batesian mimicry by an ant-like jumping spider. Biology letters, 5(6), 755-757.
Ceccarelli, F. S. (2007). Contact between Myrmarachne (Araneae: Salticidae) and ants. Arachnology, 14(2), 54-58.
Hölldobler, B., & Wilson, E. O. (1990). The ants. Harvard University Press.

Plexippus paykulli – The Evil Spiderman

By Chiu Hoi Yung, Arey (3035347017)

In the movie “Spiderman”, we often see Peter saving people by swinging across buildings with his silk . In the animal world, Plexippus paykulli is the real life Spiderman. Plexippus paykulli is a species from the family of Salticidae, which also known as “jumping spider”. It can be found quite often in buildings but they never save lives, indeed they would only kill. Rather than waiting for a stupid prey to be trapped on web, they look for prey actively during daytime. When ever they detect a “delicious meal”, they stalk, then snatch it by bouncing over it. Still, they produce silk though no “web” is made. The silk could act as a dragline to secure their long jump, just like the safetyline we wear when doing a bungee jump. Named jumping spiders, they are really good long jumpers. The longest record they made is 50 times of its body length of average 10mm. Surprisingly, these long jump medalists don’t have specialised leg muscles like grasshoppers. They leap only by a sudden force out of blood, the high blood pressure allow its hind legs to extend rapidly and sends the spider out.

What makes them jump better?

Plexippus paykulli should be grateful for having the 4 pairs of legs that equip them with high mobility. Yet, without the 4 pairs of eyes, they may not be a good jumper. Although generally spiders have 6-8 eyes, it does not guarantee for good vision. Indeed, only a few spider species have acute vision and Plexippus paykulli is the lucky one.

Plexippus paykulli have 4 sets of eyes.There are 2 large principal eyes at the centre, and 2 medium-sized eyes sit next to them. 2 smaller size of eyes are on the rear side of the head. Finally, another 2 tiny eyes sit on the two sides. But how did they make good use of the eyes?

As they are daylight hunters, excellent vision is essential for them to recognise prey and enemies. In 2012, a group of researchers led by Akihisa Terakita, from Osaka City University revealed how these eyes in jumping spiders form depth perception, which is essence of making Plexippus paykulli a never-miss-out-jumper1. Thus, they make accurate leaps so they won’t miss out the food or slip off from the gap.

The spider would use the lateral medium size of eyes to sense for a moving object. Once the movement is detected, the principal eyes would lock focus on that object. When the researchers look closer the the principal eyes, they found there are four layers of light-sensitive retina. Compared to human, we have only one layer of retina to give sensation to light. Researchers found that spiders could make accurate jump under green light in particular and consistently miss out the target under light other than green in colour. Therefore, they hypothesized that green light reflected from the target object would only focus on the deepest layer of retina, while other green light from the environment would receive as out-focused image in the others layer of retina. By comparing the blurry image and sharp image, spiders could gauge the depth cues for judging the jumping distance.

The Bold Predator

When P. paykulli detect active insect, they would approach it rapidly. When it getting closer, the spider would slow down and keep its legs tight toward its body, waiting for a good timing. By the depth perception, it bounces on the prey directly and kill it by brute strength. For larger arthropods, it would inject victim with venom to make the murder easier2.

However, direct pursuit never satisfy the aggressive P. paykulli, they would leap on other spiders’ web to catch trapped prey or even attack the web’s owner3. They would attack the resident spider or chase away large insects from the web. But what if they are also stuck on the alien’s web? Aren’t they afraid of being trapped on web? Nope! There is no such word as “Fear”for Plexippus paykulli. If they are stuck, they won’t freeze there and wait to die. Instead, they would try hard to free itself from the web.

The active web-preying behaviour is seems to be unique in Plexippus paykulli among the other jumping spider. However, there is still no evidence showing P. paykulli has any adaptive feature to take this bold act. Then it probably due to its fearlessness and impressive skill in predation.

Excellent vision and jumping capacity makes Plexippus paykulli a prominent predator. They have a wide range of prey including but not limited to mosquitoes, butterflies, dragonflies, wasp, grasshoppers and even other spiders. Although they are good at hunting, in fact they won’t prey on everything. With the acute vision, they can distinguish between species of prey and enemies. A research team led by Sajesh Vijayan from Indian Institute of Science Education and Research in 2018, has uncovered that genus of Plexippus spiders could discriminate different ant species by merely visual cues4. In their experiment, 3 different types of ant including weaver ants, golden-back carpenter ant and procession ants are exposed to the Plexippus jumping spiders. The ants were analyzed to have different colour, moving style and aggression behaviour. The results showed that spiders would give short glance on moving ants which suggests movement is important for detection. Furthermore, the glancing time on procession ants and golden-back carpenter ants were significantly longer than that of the weaver ants. Besides, spiders also spent longer time on stalking and attacking the procession ants compared to the other two.

Credit: James Marchment

It can be understood that spiders and ants live in similar habitat while both of them are top predators in terrestrial habitat. Therefore, it would be far more beneficial if spiders could avoid from enemies and invest more time on their potential meal.

Plexippus paykulli and us

Although Plexippus paykulli seems to be a cold-blood killer, it is totally harmless to human. Even if we are stinged by them, its venom would never be poisonous to us, as it cannot produce an enough dosage that may cause harmful effect to our body. Frankly, its venom is even not so effective in larger insects. Since the poison takes several minutes to take effect, and the impatient spiders usually overcome the large insects by brute strength before the prey faint.

Furthermore, recent research in 2017 are investigating the biological control method of mosquitoes using Plexippus paykulli, the mosquito-eating spiders. Therefore, from now on, Plexippus paykulli could be our good friend in manipulating disease transmitted by mosquitoes5. Seems that they are really friends of us!

Reference

Nagata, T. Koyanagi, M. Tsukamoto, H. Saeki, S. Isono, K. Shichida, Y. Tokunaga, F. Kinoshita, M. Arikawa, K. Terakita, A. Depth Perception from Image Defocus in a Jumping Spider. [Internet] 2012 Jan 27. Science. [Cited 2018 Oct 25] Available from: http://science.sciencemag.org/content/335/6067/469
Bear, A. Hasson, O. Prey capture – The predatory response of a stalking spider,Plexippus paykulli, to camouflage and prey type. [Internet] Animal Behavior. [Cited 2018 Oct 25] Available from: https://www.sciencedirect.com/science/article/pii/S000334729790525X
Jackson, R. Macnab, A. Display, mating, and predatory behaviour of the jumping spider Plexippus paykulli (Araneae: Salticidae). [Internet] New Zealand Journal of Zoology. [Cited 2018 Oct 25] Available from:https://www.tandfonline.com/doi/pdf/10.1080/03014223.1989.10422565
Vijayan, S. Casiker, C. Uma, D. Look before you jump: jumping spiders discriminate different ants by visual cues. [Internet] bioRxiv. [Cited 2018 Oct 25] Available from: https://www.biorxiv.org/content/early/2018/06/18/349696
Ndava, J. Llera, S. Manyanga, P. The future of mosquito control: The role of spiders as biological control agents: A review Jenias Ndava, Silvia Diaz Llera and Phelex Manyanga. [Internet] International Journal of Mosquito Research. [Cited 2018 Oct 25] Available from: http://www.dipterajournal.com/pdf/2018/vol5issue1/PartA/4-6-15-487.pdf

Chestnut Tiger: Not a chestnut nor a tiger

By K. W. C. Cheung

Common names can be misleading and can confuse us. For example, Electric Eel (Electrophorus electricus) is not an eel at all but a type of knifefish. The famous Killer Whale (Orcinus orca) is a dolphin instead of a whale. Here we have a Chestnut Tiger, which is neither a chestnut nor a tiger, so what is it? Despite its name, the Chestnut Tiger is a species of butterfly.

Parantica sita

Chestnut Tiger (Parantica sita) ©Ivan Lam

The Chestnut Tiger, Parantica sita, was described by Kollar in 1844. This beautiful critter has translucent streaks and spots on its black forewings and chestnut-red hindwings. It belongs to the subfamily Danainae in the family Nymphalidae, which is the largest family of butterflies. Danaid butterflies are called Tigers and Crows (here is another misleading common name). And this particular Tiger is a common species that can be found in East Asia from the Himalayan Mountains in India to Japan (Goodwyn et al., 2009). Like other members in Danainae, Chestnut Tiger is poisonous both at its larval and adult stage. The caterpillars feed on poisonous Milkweed (family Asclepiadea) and store the poison in their bodies without getting killed by it. Although the adult butterfly does not consume poisonous plant anymore, the poison it obtained during larval stage still remains in its body and makes it poisonous. Together with warning coloration, Chestnut Tiger uses this tactics to warn predators and increases its chance of surviving. Until this point, this insect may not sound particularly special or peculiar to you. Yet, never underestimate an insect.

Monarch Butterflies, Danaus piexippus, migrating in large number ©Ingo Arndt/naturepl.com

We often hear about long distance migration of larger wild creatures such as birds and mammals. Surprisingly, butterflies also undertake long distance migration. Many danaid butterfly species are known to aggregate and migrate in large number over winter. The migration of Monarch Butterfly, Danaus piexippus, is probably the most well-known butterfly migration around the world and has the farthest record of migrating distance among butterflies. Every fall, they travel up to 3,000 kilometers from Canada to Mexico for overwintering (Brower, 1995). Following this record, Chestnut Tiger is in the second place as well as the winner among oriental butterflies. In December 2011, a Chestnut Tiger from Japan was captured in Deep Water Bay Valley in Hong Kong (Kanazawa et al., 2015). The captured butterfly had been marked on its wings by the capture-mark-recapture method at Mt. Nishiyama in Wakayama Prefecture and Shirao Rindo in Kochi Prefecture in Japan earlier in October (Kanazawa et al., 2015).

The markings on the Chestnut Tiger recaptured in Hong Kong showing the date and location of previous captures in Japan ©Hf9631/Wikimedia Commons/CC-BY-SA-3.0

This was the first record of Chestnut Tiger migrating from Japan to Hong Kong. Moreover, it travelled for at least 2,420 kilometers from Mt. Nishiyama all the way to Hong Kong in 82 days, which is the farthest record known for this species (Kanazawa et al., 2015). However, this record could not reveal the exact migration route as there was no recapture record between Japan and Hong Kong. The butterfly could have travelled across the sea passing through Taiwan, or travelled to China first then move along the coast (Kanazawa et al., 2015). These proposed routes suggested that the actual migration route might be less direct and could be farther (Kanazawa et al., 2015). How can a small and fragile-looking butterfly endure such a long and difficult journey?

Migration routes.png

Shortest (solid line) and proposed (dotted lines) migration routes of the Chestnut Tiger captured in Hong Kong ©Kanazawa et al., 2015

Wings with extraordinary hydrophobicity is one of the keys towards successful migration in butterflies. Hydrophobicity is a property of repelling water instead of absorbing it or dissolving in it. Butterfly wings are famous for their superhydrophobic and self-cleaning characteristic, yet, what is the mechanism behind? On butterfly wings, there are hundreds and thousands of scales covering the surface. Apart from giving butterfly wings their beautiful color through pigments and structural coloration, these scales also give rise to the wings’ hydrophobicity. The scales overlap strongly, creating complicated surface pattern which results in a rugose surface with high contact angle (Ghiradella, 1994; Wagner et al., 1996). Higher the contact angle, lower the permeability of a certain surface. On the other hand, more hydrophobic the surface is.

As mentioned, Chestnut Tiger has translucent markings on its wings, which covers quite a large portion altogether. To be translucent, scales are modified in order to allow more light to pass through the wings. This can be achieved by having hair-like modified scales and fewer scales (Goodwyn et al., 2009). Hence, translucency in butterfly wings may indicate reduced hydrophobicity due to reduced scale cover (Goodwyn et al., 2009). However, this is not the case in Chestnut Tiger. Goodwyn and his team in the Kyoto University conducted a study to investigate translucency and hydrophobicity in Chestnut Tiger and Japanese Clouded Apollo (Parnassius glacialis). Parnassius glacialis has similar distribution with P. sita in Japan and is also translucent (Goodwyn et al., 2009). Yet, the two species have very different life cycle. Parnassius glacialis is not migratory and has short life span, unlike P. sita which can migrate over long distance, as seen above, and live for six months or more. After detailed analysis, they discovered that the translucent parts of P. sita were fully waterproof with contact angle larger than 160°, while that of P. glacialis were less hydrophobic with contact angle between 100°-130° (Goodwyn et al., 2009). This difference is due to the shape and pattern of the specialized scales and the topography of the wing surface in P. sita (Goodwyn et al., 2009). Moreover, even if the specialized scales on the translucent parts leave 88% of the wing surface uncovered, the hydrophobicity between translucent portions and portions with normally overlapped scales did not have much difference (Goodwyn et al., 2009). The superhydrophobicity provided by the specialized structures on Chestnut Tiger’s wings aid the survival in the long and difficult migration.

Although Chestnut Tiger is not really a tiger, the secrets hidden in its wings are still fascinating, making it one of the butterfly species with the longest migration distance and one of the special creations of nature.

References:

Brower, L. P. (1995). Understanding and misunderstanding the migration of the monarch butterfly (Nymphalidae) in North America: 1857-1995. Journal of the Lepidopterists Society, 49(4), 304-385.
Ghiradella, H. (1994). Structure of butterfly scales: patterning in an insect cuticle. Microscopy research and technique, 27(5), 429-438.
Goodwyn, P. P., Maezono, Y., Hosoda, N., & Fujisaki, K. (2009). Waterproof and translucent wings at the same time: problems and solutions in butterflies. Naturwissenschaften, 96(7), 781-787.
Kanazawa, I., Cheng, W. W. W., Pun, H. S. F., Sakiyama, Y., & Doi, H. (2015). First migration record of Chestnut Tiger Butterfly, Parantica sita niphonica (Moore, 1883)(Lepidoptera: Nymphalidae: Danainae) from Japan to Hong Kong and longest recorded movement by the species. The Pan-Pacific Entomologist, 91(1), 91-97.
Wagner, T., Neinhuis, C., & Barthlott, W. (1996). Wettability and contaminability of insect wings as a function of their surface sculptures. Acta Zoologica, 77(3), 213-225.

Scutigera coleoptrata – More Than Just a Horrifying Appearance

By Kan Karin (UID: 3035277133)

Speaking of scary bugs, what come to your mind? Some typical answers are cockroaches, spiders. Wait till you meet Scutigera coleoptrata! It claims the title of “The Grossest Bugs on Earth” with 820 votes on ranker.com.

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First described and named by Carl Linnaeus in 1758, Scutigera coleoptrata is a centipede that belongs to the family Scutigeridae. They are commonly known as house centipedes cause they are frequently spotted at homes or indoor area in Europe, Asia, North America and South America, but less in Hong Kong. According to molecular evidence, the evolution tree reveals that they split early from the rest of the centipedes, whose fossil record extends back to 430 million years ago. In other words, they are quite ancient!

An adult of S. coleoptrata can reach up to 100mm and has an average lifespan of 3-7 years. Its yellowish-grey body connects to 15 pairs of legs. Looking directly from the top, three signature dark stripes running from head to tail can be seen. Young S. coleoptrata don’t look too “leggy”. When they first hatch from eggs, they have only 4 pairs of legs. With their first molting, they gain one pair more. For the next five molting, they gain two pairs more each time until they reach 15 pairs. Then they will retain this number for the rest of their life. Not only do these long legs give them a terrifying appearance, but also the power to run super fast (up to 0.4 m/s), be it on floor, on the walls or upside down on the ceilings.

220px-Scutigera_coleoptrata_MHNT_

From this picture, can you tell which end is its head? It is actually quite hard to tell. The last pair of legs of S. coleoptrata is modified into a pair of long, fine structures that resemble its antennae. This is a called automimicry, in which the animal get protection from mimicking its own body part. In this case, the centipedes confuse the predators and deflect attacks from the vulnerable head.

S. coleoptrata are carnivores, which means they feed on other arthropods, such as spiders, termites, cockroaches and ants. Their long and sensitive antennae can sense touch and smell, which help them detect possible preys. Although their long delicate legs may disgust some people, they are very useful when it comes to preying! They jump on to the prey in a flash then lasso them, or even beat them with those dark-striped legs. Moreover, like all others centipedes, they penetrate preys with fangs that connected to venom glands to paralyze preys. Last but not least, studies show that S. coleoptrata turns out to have well-developed compound eyes! This is uncommon among centipedes because centipedes are nocturnal. Their good vision give them visual information that favors hunting. All these hunting skills and advantages make them master in capturing insects!

HouseCentipedeHeadFangs

At homes, S. coleoptrata are mostly found in the bathroom and kitchen. Why? Centipedes lack structure that cover the spiracles. Spiracles are holes on insects that serve to inhale oxygen into their body. This makes them vulnerable to dehydration and coldness, so these creepy sneaky guys prefer living in damp , humid places. On the other hand, some of them don’t live with human and are found in the wild. Wild S. coleoptrata live in cool places, usually underneath the rock, among the wood or organic matter.

There was a saying from 19th-century Buddhists poet which I particularly find amusing — “if you enjoy frightening others, you will be reborn as a centipede.” Unsurprsingly, people are invariably frightened by S. coleoptrata’s unpleasant appearance and want to kill them right away when they appear at their home. Nevertheless, they are actually harmless to human. Their fangs are not strong enough to penetrate through human skin, let alone poisoning us. Even if they sting human, the venom are far from fatal and will only cause swelling and redness. When spotted by human, it can be sure S. coleoptrata are much more frightened than we are. They will become motionless for a while in hope of not being seen by us, then run for their life with their astounding speed, disappearing into cracks or darkness. If you try to catch it, be sure you don’t grab them with their legs! They are able to detach any of its legs in order to escape.

Many people try to make S. coleoptrata disappear from their houses. However, if you get to know more about them, you will realise there are actually something more other than their horrifying look. See it from the bright side, they can work as pest control at your home! My house has quite a few cockroaches. Maybe it’s a good idea to let one or two S. coleoptrata live in my house. You know how the old saying goes…..the enemy of my enemy is my friend!

Reference

Lewis, J. G. E. (2006). The biology of centipedes. Cambridge university press.
Müller, C. H., Rosenberg, J., Richter, S., & Meyer-Rochow, V. B. (2003). The compound eye of Scutigera coleoptrata (Linnaeus, 1758)(Chilopoda: Notostigmophora): an ultrastructural reinvestigation that adds support to the Mandibulata concept. Zoomorphology, 122(4), 191-209.
Kusche, K., Hembach, A., Hagner‐Holler, S., Gebauer, W., & Burmester, T. (2003). Complete subunit sequences, structure and evolution of the 6× 6‐mer hemocyanin from the common house centipede, Scutigera coleoptrata. European Journal of Biochemistry, 270(13), 2860-2868.
Negrisolo, E., Minelli, A., & Valle, G. (2004). Extensive gene order rearrangement in the mitochondrial genome of the centipede Scutigera coleoptrata. Journal of molecular evolution, 58(4), 413-423.
Edgecombe, G. D., & Giribet, G. (2007). Evolutionary biology of centipedes (Myriapoda: Chilopoda). Annu. Rev. Entomol., 52, 151-170.
Edgecombe, G. D., & Giribet, G. (2006). A century later–a total evidence re-evaluation of the phylogeny of scutigeromorph centipedes (Myriapoda: Chilopoda). Invertebrate Systematics, 20(5), 503-525.

Monstrous organ of beautiful moth: The mysteries of Creatonotos gangis’s coremata

BIOL3419 Insect Ecology Assignment 1

Name: Mak Hin San Paul

UID: 3035280788

Insect: Creatonotos gangis

Words: 1175

“Is this a monster in a horror movie?”

As a kind of moth, Creatonotos gangis is quite famous on the internet. There was a time that their pictures and video records spread infectiously among different social platforms. People were shocked by Creatonotos’ weird appearance – those massive, furry, trembling tentacles which streaking away from its end of abdomen. Some comments said that it likes the nightmare-version of a monster “Mothra” in “Godzilla” movies.

Figure 1 – The mysterious, hairy and massive organ that impressed many people.Source: David Smiley. (2014). Coremata. BunyipCo. Retrieved from:http://bunyipco.blogspot.com/2014/08/coremata.html

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Figure 2 Some people think Creatonotos gangis is as weird as the monster in “Godzilla” movies. Draw by: Mak Hin San Paul (2018)

Coremata – the important tool for seeking love

Creatonotos gangis is a kind of common tropical moth which mainly distribute in South-east Asia and northern Australia, and it was described by Carl Linnaeus in 1763 (Carl, 1763). The appearance features of Creatonotos gangis adults include a pair of white hindwings, brown forewings with the dark stripe showed up and the red color abdomen. Also, the males have four eversible and tubular structure scent organs called “Coremata” located in the dorsal part of the abdomen, the size of coremata can exceed the length of the whole abdomen when it is bloated (Peter, 2012).

Although many people seem horrified by knowing the existence of this strange insect, its dangly organ, coremata, is not unique to Creatonotos gangis. Many lepidopteran males have a specific structure which functions as a scent organ for seeking females (Birch and Hefetz, 1987). The size and shape of this organ largely diverse among different Lepidoptera species, and it can be divided into two forms – coremata and hair-pencils. The definition of coremata is controversial but generally coremata is defined as a glandular and eversible organ that cloths with hair-pencils and it can secrete pheromone for attracting mates (Birch et al., 1990; Pagden, 1957).

The reason that people are not familiar with this peculiar organ maybe because Lepidoptera species usually would not show off this distinctive organ. In most of the time, coremata is stored in the abdomen, therefore, it is rare to witness the lepidopteran swelling their coremata in natural situation.

Figure 3 The appearance of Creatonotos gangis with no inflated coremata. Photograph by 吳子健Source: Dearlap.tw. Retrieved from: http://dearlep.tw/species.html?namecode=343822&photo_id=2f00563786b43a31015f5d4d26e773f2

As a signaling organ, coremata plays an important role in courtship. When male detects the pheromone released by female and they get close enough, male will let his coremata fill with hemolymph (a liquid similar to blood in most insects) or air to expand the structure (Birch et al., 1990). Once the coremata expanded, the fair-like scent scales on the surface would erect to release the stored pheromone (Bober & Rafaeli, 2010). If the pheromone released by male able to attract the female, they will start mating. Therefore, even though the appearance of coremata might be scary to human, it is an essential part for some Lepidopteran to make their own romantic stories.

Figure 4 The scent scales on the coremata can erect and release the pheromone. Source: Davenport, J. W., & Conner, W. E. (2003). Dietary alkaloids and the development of androconial organs in Estigmene acrea. Journal of Insect Science, 3(1), 3.

Scientific Terminlogy (Not explained in the article)

Lepidoptera	An order of insects, consists of butterflies and moths.
Lepidopteran	The organisms that belong into Lepidoptera.
Hindwings	The two back wings in four-wings insect.
Forewings	The two front wings in four-wings insect.
Scent organs	The organs that specialized to secret strong-smelling substance.
Elementary metabolism	A basic set of chemical reactions that keep organisms sustain life.
Asteraceae	A huge and widespread family of flowering plants. (Examples: chrysanthemum, common sunflower, daylily)

Reference

Biswas, O., Modak, B. K., Mazumder, A., & Mitra, B. (2016). Moth (Lepidoptera: Heterocera) diversity of Sunderban Biosphere Reserve, India and their pest status to economically important plants. Journal of Entomology and Zoology Studies, 4(2), 13-19.
Birch, M., and Hefetz, A. 1987. Extrusible organs in male moths and their role in courtship behavior. Bulletin of the Entomological Society of America 33: 222-229.
Birch, M. C., Poppy, G. M., and Baker, T. C. 1990. Scents and eversible scent structures of male moths. Annual Review of Entomology 35, 25-28.
Bober, R., & Rafaeli, A. (2010). Gene-silencing reveals the functional significance of pheromone biosynthesis activating neuropeptide receptor (PBAN-R) in a male moth. Proceedings of the National Academy of Sciences.
Boppré, M., & Schneider, D. (1985). Pyrrolizidine alkaloids quantitatively regulate both scent organ morphogenesis and pheromone biosynthesis in maleCreatonotos moths (Lepidoptera: Arctiidae). Journal of Comparative Physiology A, 157(5), 569-577.
Boppré, M., & Schneider, D. (1989). The biology of Creatonotos (Lepidoptera: Arctiidae) with special reference to the androconial system. Zoological Journal of the Linnean Society, 96(4), 339-356.
Carl Linnaeus. (1763). Centuria Insectorum.
Davenport, J. W., & Conner, W. E. (2003). Dietary alkaloids and the development of androconial organs in Estigmene acrea. Journal of Insect Science, 3(1).
Hartmann, T. (1999). Chemical ecology of pyrrolizidine alkaloids. Planta, 207(4), 483-495.
Holland, D., Hatib, K., & Bar-Ya’akov, I. (2009). 2 Pomegranate: Botany, Horticulture, Breeding. Horticultural reviews, 35(2), 127-191.
Jacobson, M. (1974). Insect pheromones. In The Physiology of Insecta (Second Edition), Volume III (pp. 229-276).
Kirkpatrick, M., & Ryan, M. J. (1991). The evolution of mating preferences and the paradox of the lek. Nature, 350(6313), 33-38.
Linnaeus, C. (1763). Vol. 2. Species Plantarum. ed. 2. Stockholm.: 785-1684 (1685-1748).Experimental biology, 46(1), 11-27.
Pagden, H. T. (1957). THE PRESENCE OF COREMATA IN CREATONOTUS GANGIS (L.)(LEPIDOPTERA: ARCTIIDAE). In Proceedings of the Royal Entomological Society of London. Series A, General Entomology (Vol. 32, No. 4‐6, pp. 90-94). Oxford, UK: Blackwell Publishing Ltd.
Peter Hendry, The Australian Arctiid Moths (Lepidoptera: Noctuoidea: Erebidae) with emphasis on Creatonotos Gangis, Metamorphosis Australia, Issue 65 (June 2012), pp. 1, 4-7, Butterflies and Other Invertebrates Club.
Nishida, R., Schulz, S., Kim, C. S., Fukami, H., Kuwahara, Y., Honda, K., & Hayashi, N. (1996). Male sex pheromone of a giant danaine butterfly, Idea leuconoe. Journal of chemical ecology, 22(5), 949-972
William E. Conner. (2009). Tiger Moths and Woolly Bears– Behavior, Ecology, and Evolution of the Arctiidae. USA. Oxford University Press.
Wunderer, H., Hansen, K., Bell, T. W., Schneider, D., & Meinwald, J. (1986). Sex pheromones of two Asian moths (Creatonotos transiens, C. gangis; Lepidoptera–Arctiidae): behavior, morphology, chemistry and electrophysiology.

Cyrtotrachelus longimanus – the elephant on the bamboo plant

“As an insect, I am very sad that everyone claimed that is a big “nose”” said Cyrtotrachelus longimanus (Common name: Bamboo Weevil大竹象)^[1]which has also given the “bamboo elephant” description in Chinese. The truth is the “nose” is actually a long snout (an anterior prolongation of the head of insect), which is specialized to bores holes on the bamboo, and allow laying eggs inside. There is and geniculate antennae with small clubs attach on the middle part of snout, which act as a sensation function. Cyrrobracheluslongimanus

Photo from PCAS FEHD HKSAR

This species is commonly spread around Asia, relay on plenty of bamboo trees, including: Bambusa emeiensis(also named as Omei Mountain Bamboo, commonly used as raw material for paper production in China), Dendrocalamus strictus, Melocanna baccifera and other species of bamboos in South Asia and China. ^[1]^[2]

They life cycle is heavily depend on bamboo tress: When bamboo develop the tender tissue, Cyrtotrachelus longimanus adult will end the hibernation (usually 10 months) and feed on tender tissue, each feeding time will last for 4-5 hours. After two days, Cyrtotrachelus longimanus will reproduction and female Cyrtotrachelus longimanus will drill a hole on bamboo for oviposition (deposit egg through an ovipositor)^[3].They will laid one (maximum two eggs inside) in each bamboo plant. Each time they can produce 25-30 eggs, which also mean each female can laid eggs on 25 bamboo plants.^[1] Egg of Cyrtotrachelus longimanus will later develop to a white and legless larva, also with a brown head capsule and well-developed jaws^[3]. Larva feed on young bamboo shoots from the first day. After four weeks, it grow up to 4-5cm and move back and enlarging the upper portion of the bamboo (about 130-200mm from the top). They will then fall to the ground bearing the fully-grown grub. The grub later burrows into the fallen buried rottened shoot. They will create a pupal cell by bamboo fiber and mud and hibernate in it (which last for 10 months). ^[1][2][3]

The nightmare of bamboo farmer

The damage of Cyrtotrachelus longimanus to bamboo trees is tremendous. Cyrtotrachelus longimanus larvae created a long tunnel, passing internally through several internodes by perforating each node, which start from the beneath or near the culm sheath, and ending in a terminal shoot. The bamboo become fragile and loss of commercial value (no longer useable as raw paper material). Since one larva is capable for destroying one culm, a great number of larva (~25-30 eggs per year per female) leads to a great loss for the bamboo farmers. Take Sichuan province Lingmu county as an example, more than 90% of the bamboo farm is threatened and lead to 55% loss of total bamboo production per year, which is about RMB 30million loss^[1]. Of course, Sichuan province government try to work on this, but the result is unsatisfactory. The current method included direct catching (reduce the number of sexual mature adult so as to limit the reproduction amount), spreading fungi and spreading pesticide^[1]. As Cyrtotrachelus longimanus larvaes live inside the bamboo, and the majority time of life cycle is overwintered underground. Thus, these methods all require a large human force in a short time (for example, direct catching is limited within the 2 days breeding period), and limited the efficiency of population control. New method such as introduction of natural predator is also proposed to against this situation^[1], but there not successful case reported on these methods currently^[3].

The Hope for scientists

However, every coin had two sides, the nightmare for farmer now inspiring scientists to develop new material. Cyrtotrachelus longimanus’ rostrum is a hollow multilayered cylindrical structure, which maximally save materials while ensuring enough strength and stiffness (it require electric dill to break it). For human, this a brand new material different form traditional metals and polymer. And the existing rostrum from Cyrtotrachelus longimanus provides a biological template to design a new lightweight structure and materials. Which is very helpful in high-tech industries, such as aerospace and biomedical applications^[4]^[5] . Yi & Du^[6] has given an example to lustrate this idea, , if the weight of a three-stage engine for a missile with a range of 1000 km decreases by 1 kg, the range can increase by 17 km, and if the weight of a bullet decreases by 1 kg, the range increases by 25 km. If the mass of the structure decreases by 1 kg, a spacecraft can save 20 kg in fuel consumption.^[4]^[5] A small reduction in weight can greatly lower the fuel consumption, as well as opening more possibility for technology progression and human exploration.

Reference List

WD WONG, XQ WONG, FZ CHENG. Preliminary Investigation on Cyrtotrachelus longimanus in Sinocalamus affinisof Muchuan County. 2002 (in Chinese)
The Review of applied entomology. London: Published by the Imperial Bureau of Entomology; 1917.
Hill D. Pests of crops in warmer climates and their control. [Place of publication not identified]: Springer; 2010.
Li L, Guo C, Li X, Xu S, Han C. Microstructure and mechanical properties of rostrum in Cyrtotrachelus longimanus (Coleoptera: Curculionidae). Animal Cells and Systems. 2017;21(3):199-206.
Li L, Guo C, Xu S, Li X, Han C. Morphology and nanoindentation properties of mouthparts in C yrtotrachelus longimanus (Coleoptera: curculionidae). Microscopy Research and Technique. 2017;80(7):704-711.
Yi WK, Du B. 2003. Aerospace manufacturing technology. Beijing: China Astronautic Publishing House.

Just Mimics or Something Much More? – The Orchid Mantis (Hymenopus coronatus)

Ever since it was first discovered by late-19^th century explorers in the forests of Indonesia, the orchid mantis (or Hymenopus coronatus) has captured the imagination of experienced ecologist and novice insect collectors alike. ¹

While orchid mantises, like other praying mantises in the insect order Mantodea, are a generalist predator that uses its long, raptorial legs to seize unsuspecting prey, their distinctive coloration and morphology gives rise to a relatively unique style of hunting.¹¹

Instead of sporting a natural green and brown color to blend into its surroundings, orchid mantises stand out from the foliage with its bright white body complete with hints of pink and yellow hues. ⁸ This combined with its broad abdomen and petal-like exoskeleton extensions on four of its legs, known as femoral lobes, allows the mantis to look – at least to the human eye – like an orchid flower. ^6,7

Image by Antonio Giudici via https://flic.kr/p/nvouEF

But are they mimicking the flowers to attract pollinators for food?

More to the point, do they even look like flowers to other insects?

Surprisingly, while H. coronatus has for years been the go-to example for deceptive mimicry in action, relatively little has been studied about the insect. In fact, most of the information we know about them seems to come from a few anecdotal accounts by Arthur Russell Wallace, a prominent evolutionary theorist, and a single 1899 observation of the insect! ⁸

Believe it or not, it wasn’t until 2013 that the first paper describing the distinctive characteristics of the orchid mantis in scientific detail was published! ⁸

In a groundbreaking paper exploring H. coronatus, Dr. James C. O’Hanlon and his team examined dozens of orchid mantises using spectral reflections and digital scans to quantify their color and femoral lobe shape.⁸

All of the mantises tested showed a primarily white signal that was UV-absorbing. While some differences in individual hue were observed, the results were below a “discrimination threshold” that researchers applied, which took into consideration other confounding factors like lighting conditions.⁸ The insect’s lobe shape varied slightly both between and within individuals, though not enough to be considered significant. In short, while they may sometimes look different from each other, quantitatively speaking they’re more or less identical.⁸

Not satisfied with just a superficial description, the team went on to put several commonly held beliefs to the test, with surprising results!

Firstly, through habitat experiments, they supported the idea that H. coronatus are aggressive mimics which actively lures prey to themselves, a bit like an angler fish with its glowing “lure”, rather than cryptically hiding among similarly colored flowers to catch unaware pollinators. ⁶

However, the insect it actually doesn’t closely resemble any known species of orchid.

Instead, the orchid mantis actually attracts pollinators to itself BETTER than real flowers!⁷

How?

One theory suggests that because orchid mantises consume a wide range of insects, they may have evolved to mimic generalized “flower-like” stimuli, such as symmetry and bright coloration which reflects UV light, rather than mimic a specific flower whose pollinators may be constrained to a specific region or habitat. ⁵

And those petal-like extensions that often fool us?

Their studies show that even with the extensions removed or held at unnatural positions, no significant change in prey capture was seen, suggesting that it’s color not “petal” shape attracts the insects. ^6,7So perhaps the features are used to avoid predators with more complex eyesight, as they are virtually indistinguishable from flowers to different bird visualization models?⁷ Maybe they are mechanism for tricking pollinators up close, after the prey have been lured in by the mantis’ alluring color?⁶ Or it could just be a way for the mantis to increase its surface area so that it can be spotted from afar by potential prey.⁷

Truthfully, scientists aren’t quite sure of the answer at the moment…

Indeed, it seems that the more we look into the species, the more we find left to discover and study!

Visual cues may just represent one of the many ways H. coronatus trick their prey.⁸

After noticing that juvenile orchid mantises seem to have more success catching oriental honeybees (Apis cerana) than their adult counterparts, Dr. Takafumi Mizuno and his team set out to see if something else was helping them lure the bees.⁴

Turns out the juveniles release volatile chemicals from their mouth parts that are also used by the bees for communication, which not only gives juveniles a second form of aggressive mimicry but also attracts the bees head-on to the mantis, directly toward its raptorial limbs!⁴

What about repelling unwanted predators who might want to snack on the mantises before they grow to their flower-like color, size and morphology?

Well, insect keepers have noted that in the short span of time between when they hatch out of its egg case (or ootheca) and when they molt for the first time, the color of H. coronatus is vastly different from when they are juveniles or adults. ^1,2,3 During this stage, also known as the insect’s first instar, the young mantises are bright red and appear to “walk” on all six of their legs, which are black in color!³

Once again, while observation data has repeatedly confirmed this occurrence in captivity and researchers have suggested that they are mimicking undesirable insects such as Assassin bugs (in the family Reduviidae), the hypothesis has never been experimentally tested.¹

3393957101_f1aace28dd_z — Image by Scott Thomas via https://flic.kr/p/6aUVcK

H. coronatus might even be the gateway species that changes how we view common arthropod phenomenon such as sexual size dimorphism, where the females of a species are much larger in size than the males.

Previously, it was assumed that the difference was exclusively to help with female reproductive success, as in general “the larger the female, the [more] offspring”. ⁹ However, a phylogenetic study by Dr. Gavin J. Svenson and his team show that – at least in the case of H. coronatus – predatory success and niche exploitation based on sex may have cause the females to become much larger to mimic flowers more closely and take on larger prey, while the males remained smaller to help with finding a mate without alerting potential predators.⁹

In short, as charismatic and captivating H. cornonatus may be, they remain critically understudied.

Far beyond “just pretending to be an orchid”, numerous papers published in the last few years point to a complex relationship between an orchid mantis’ age and sex which radically alters its behavior, survival and hunting strategy.

So the next time you hear another fascinating story or observe some compelling behavior in insects, don’t be satisfied with the first thing that pops up on the internet. Instead, take a second to look deeper into the scientific literature.

You may just discover that you are delving into a whole new world of knowledge that’s just waiting to be explored.

Remember: looks can be deceiving, so never judge a book by its cover… or in this case, a bug by its color!

References:

Gurney, A. B. (1950). Praying Mantids of the United States, Native and Introduced. Annual Report of the Board of Regents of the Smithsonian Institution. The Smithsonian Institution. 105: 344–345.

Linda, M. (2017). Orchid Mantis. Retrieved October 16, 2018, from https://www.keepinginsects.com/praying-mantis/species/orchid-mantis/

Menth, L. (2015). A Deceptive Flower – Malaysian Orchid Mantis. Retrieved October 18, 2018, from https://creaturefacts.wordpress.com/2015/06/

Mizuno, T., Yamaguchi, S., Yamamoto, I., Yamaoka, R., & Akino, T. (2014). “Double-Trick” Visual and Chemical Mimicry by the Juvenile Orchid Mantis Hymenopus coronatus used in Predation of the Oriental Honeybee Apis cerana. Zoological Science, 31(12), 795-801. doi:10.2108/zs140126

O’Hanlon, J. C., Herberstein, M. E., & Holwell, G. I. (2014). Habitat selection in a deceptive predator: Maximizing resource availability and signal efficacy. Behavioral Ecology, 26(1), 194-199. doi:10.1093/beheco/aru179

O’Hanlon, J.C., Holwell, G.I, Herberstein, M.E. (2013) Pollinator deception in the orchid mantis. The American Naturalist 183(1): 126-132. https://doi.org/10.1086/673858

O’Hanlon, J.C., Holwell, G. I., & Herberstein, M. (2014). Predatory pollinator deception: Does the orchid mantis resemble a model species? Current Zoology, 60(1), 90-103. doi:10.1093/czoolo/60.1.90

O’Hanlon, J.C., Li, D., & Norma-Rashid, Y. (2013). Coloration and Morphology of the Orchid Mantis Hymenopus coronatus (Mantodea: Hymenopodidae). Journal of Orthoptera Research, 22(1), 35-44. doi:10.1665/034.022.0106

Svenson, G. J., Brannoch, S. K., Rodrigues, H. M., O’Hanlon, J. C., & Wieland, F. (2016). Selection for predation, not female fecundity, explains sexual size dimorphism in the orchid mantises. Scientific Reports, 6(1). doi:10.1038/srep37753

Wipfler, B., Wieland, F., Decarlo, F., & Hörnschemeyer, T. (2012). Cephalic morphology of Hymenopus coronatus (Insecta: Mantodea) and its phylogenetic implications. Arthropod Structure & Development, 41(1), 87-100. doi:10.1016/j.asd.2011.06.005

Image resources:

Giudici, A. (2014). Orchid Mantis. Retrieved October 24, 2018, from https://flic.kr/p/nvouEF
Thomas, S. (2009) 1^st instar Hymenopus cornatus Retrieved October 24, 2018, from https://flic.kr/p/6aUVcK

The False Accusation of a Century – Gryllotalpa africana, de Beauvois

By Nicholas

When it comes to sound production, few in the insect world can come close to the magnitude and beauty of crickets. Countless enisiferans (the crickets, katydids and alike) made their name not only by being nature’s best musicians, but also by being terrible agricultural pests all over the world. Gryllotalpa africana (de Beauvois,1805), the African Mole Cricket, is one of the most feared and wanted outlaws, thought to terrorize farmlands from Africa to America and even in Asia. However, more recent studies reveals that G. africana had been falsely framed for the misdoings of their close relatives in other countries. Today we dive deep into the secret subterranean life of mole crickets and deep into the case of a false accusation of a century.

What is the mole cricket?

First, we must learn about the mole crickets themselves. Judging by its appearance, the mole cricket might not look like a typical orthopteran (order of insects including the grass hopers, locusts, crickets and relatives) aside from its elongated and muscular hindleg, and there is a very good reason for that.

As its name suggests, the “mole” cricket lives somewhat similarly to the mammal that inspired its name, spending most of its life (including the egg and nymph and part of the adult stages) underground. While males seldomly fly, females emerge from their burrows only in specific times of the year to find their mates and a suitable patch of soil to lay their eggs. Aside from that, mole crickets live in underground tunnels they dig, performing major functions of life such as feeding, escaping from predators, mate attraction, mating and the raising of their young. (Capinera, 2008)

Adapting to this mode of life, mole crickets has reduced eyes (there is not enough light underground for eyes to be useful); strong fore arms which are flattened and shovel like allowing the cricket to push through soil easily and rapidly; distinguished, sclerotinised (hardened) head, fore limbs and prothorax that protects and aids the insect during the burrowing action; and finally a head shaped like a half cone, which is also prognathous (with mouthparts pointing forward) unlike other orthopterans (which has their mouthparts pointing downward), to minimize resistance when the mole cricket digs (Luh & Hwang, 1951); all of which contributes to its unique appearance.

Burrowing behaviour

The science behind the burrows of the mole crickets are equally fascinating. As aforementioned, the burrows of mole crickets hold various functions, and in order to perform such functions more efficiently mole crickets are able to create at least two different burrow structures: the living burrow and the acoustic burrow, for different uses. (Baker, 2016) Living burrows can be dug both horizontally and vertically, while horizontal burrows allow mole crickets to feed on either shallow roots or even trap small arthropods for predatory mole crickets; vertical burrows allow some mole crickets to consume subterranean stems of plants and provides a safe place for them to moult, out of reach from predators.

Acoustic burrows on the other hand, are burrows that are created specifically for a male mole cricket to reside and sing in, with elaborate structures such as a bulb, horns that amplifies the vocalizations of the mole cricket and even an exit tunnel for emergency.

Stridulation of mole crickets

The calling song of male mole crickets confuses many, as no one would suspect an underground cricket which is rarely observed by humans to be able to produce vocalizations of such a magnitude. Like other enisiferans, mole crickets produce sounds through an action called stridulation: where an animal produces sound by rubbing together certain body parts: involving the scraping of the plectrum (a structure with tip or nodules) against a stridulitrum (a finely ridged surface).

For the case of the mole cricket, the rear edge of the left fore wing is scrapped as a plectrum across the lower surface of the right fore wing, which has a series of asymmetric teeth. (Bennet-Clark, 1970) As the calling song is essential to the reproductive success of males, songs are species specific, and subsequently the morphology of the teeth on the right forewing of each species is also different, which applies to our species G. africana. (Graap et. al, 2005) Let us hold on to this fact for now.

Gryllotalpa africana as pests

Although being interesting subterranean creatures to study, the habits of the mole crickets proof to be quite a handful as they are treated as pests in any region that they occur in. Not only do some mole cricket species directly feed on underground roots or underground stems, the burrowing behavior of mole crickets will push up the top few centimeters of soil in little ridges, causing the surface moisture to evaporate, disturbing the germination of seeds.

The African mole cricket is an offender of both of the above crimes (Baker, 2016) and is thus labelled as a major pest as it is known to target commercial crops such as cabbage, rice, tea and tobacco. Not only is the species a major pest in its native region: South Africa, it had also managed to distribute itself into the far reaches of Asia and America, becoming an invasive, global threat economically. Or did it?

Criminal undercover

Turns out that you cannot judge a book by its cover! Although morphologically similar under the naked eye, the species once recognized to be Gryllotalpa africana in Asia (described as early as in 1929) (康, 1993) is in fact Gryllotalpa orientalis. The African mole cricket should be recognized as a species group (which refers to a group of species that is very similar in appearance and hard to distinguish reliably) instead and Gryllotalpa africana does not occur outside of Africa! (Towsend, 1983)

Remember how the calls of male mole crickets are species specific and that each species of mole crickets has a difference in the morphologies of their stridulating organs? Using the analysis on sound profile of the mating calls and studying the different number, shape and even distance between each ridge in the stridulum, Towsend (1983) managed to recognize the Asian populations of the once misrecognized G. Orientalis to be different from the true G. africana in Africa.

The African mole crickets have been bearing the verdict of being a pest in Asian countries while in truth they do not even live in the region!

Even as pests, the story of mole crickets and especially the confusion between G. africana and G. orientalis is still fascinating and full of twists. Many more mysteries surround the little-known world of insects, how many more cases of cryptic species could we bust open in the future?

References:

Baker E. (2016) The burrow morphology of mole crickets (Orthoptera: Gryllotalpidae): terminology and comparisons. PeerJ Preprints 4:e2664v1

Bennet-Clark, H. C. (1970). “The Mechanism and Efficiency of Sound Production in Mole Crickets”. Journal of Experimental Biology. 52: 619–652.

Capinera J. (2008). Encyclopedia of Entomology. Springer Science & Business Media. p. 3983–3984.

Graap J. Schoeman A. Brandenburg R. (2005). STRIDULATION OF GRYLLOTALPA AFRICANA (ORTHOPTERA:GRYLLOTALPIDAE) ON TURF GRASS IN SOUTH AFRICA. Florida Entomologist. 88(3). p.292-299

Luh P.L., Hwang K.H. (1951). The External Morphology of the Mole-cricket, Gryllotalpa africana de Beauvois, (Orthoptera: Gryllotaplidae). I. The Head and Feeding Mechanism. 中國昆蟲學報. 1(3). p. 308-320.

Towsend B. (1983). A revision of the Afrotropical mole-crickets (Orthoptera: Gryllotalpidae). Bulletin of the British Museum (Natural History). 46(2). p.175-203

康樂. (1993). 我國的“非洲螻蛄”應爲“東方螻蛄”. ENTOMOGICAL KNOWLEDGE. 30(2). p.124-127

The Attractive Beetle that Nobody Praises – Popillia japonica (the Japanese beetle)

Take a look at these pictures. Doesn’t the colorful beetle catch your eyes? This is Popillia japonica, commonly called the Japanese beetle, and was first described by the scientist Newman in 1841. As its name suggests, the Japanese beetle is native to the main islands of Japan, and was common in the grasslands of Kyushu, Shikoku, Hokkaido, and Honshu.¹ Belonging to the family Scarabaeidae – a family in which many bright metallic-colored beetles are found, this beetle is no exception. Its oval body is beautifully colored, with iridescent copper-brown elytra (i.e. the hardened wings) and metallic green head and thorax. It is not a very large beetle, but is still quite visible with naked eyes, as its adult measures around 0.5 inch (or 1.3 cm) in length.²

(Photos from Shutterstock. https://www.shutterstock.com/)

The Interesting Behaviors

The Japanese beetles are small but interesting creatures. Like many insects, they feign death when they are threatened or attacked – by drawing their legs close to the body and dropping themselves to the ground while landing on their backs, and then they may stay there for a while to continue playing dead, or make an effort to turn their oval little bodies around and run frantically to hide themselves under litter or underground.¹ However, the most unusual part about their defense behavior is not how they pretend to be dead, but the curious habit of the beetles extending their metathoracic legs oblique to their bodies when a potential enemy approaches. In fact, such peculiar behavior is shared among other beetles in the family Scarabaeidae, and is presumably for signaling other beetles, as it was reported that different individuals relay this behavior for 8 to 10 feet down a row of plants they are feeding on, that they only stopped when the enemy passes.¹What is even more interesting is that the display of this strange habit is actually related to environmental conditions. With high temperature (>29°C) and low relative humidity, the Japanese beetles no longer extend their legs, but become so sensitive and nervous that they will fly instead.¹

Flight of the Japanese beetles is another intriguing behavior to look into. Most of them are just flying short distances from plant to plant, but as they fly restlessly, plus the fact that their tiny light-weighted bodies can easily be carried by wind, the total distance they are able to fly can be quite impressive. Decades ago, there was already an entomologist reporting an offshore wind that carried millions of Japanese beetles over a remarkable distance of 5 miles off the coast, in just one sustained flight.⁸This beetle’s capability in flight therefore cannot be underestimated – as the saying goes, you can’t judge a beetle by its elytra!

Life as a Beetle

The flight of the Japanese beetle is certainly amazing, but the beetles are obviously not spending their whole lives flying around. They have main tasks in their lives to keep themselves and their species alive, and foraging is one of those tasks. For the Japanese beetle, finding food is not that difficult, since they are phytophagous insects that feed on many types of plants. Yet they do have preferences, and many experiments have shown that they prefer plants with a fruity odor and high sugar content.^6,7You may start to wonder what is the importance of this, as preferences for sugary food is not uncommon among animals. Well, this is because the beetles’ feeding and preferences is related to their oviposition, or, the laying of eggs. Female beetles tend to lay eggs near the plant she has been feeding on, so population of the Japanese beetles are always more concentrated around their preferred plants.¹

A simple reproduction strategy, isn’t it? The Japanese beetle’s life history and emergence are much more complicated on the other hand, for they vary depending on the beetles’ geographical location. Generally, they only have one generation per year (although there are exceptions), emerging in July.¹ A Japanese beetle’s life starts in September, when eggs are burrowed 2 to 3 inches into the soil of healthy and vigorous lawns, and hatch as grubs in around 2 weeks.^3,4 The grub will then consume the fine rootlets of plants until cold weather approaches, when they have to burrow 4 to 8 inches down the soil to hibernate.^2,4In spring the beetles resume feeding again, and within 4 to 6 weeks they pupate, and after another 2 weeks they emerge as adult beetles.^1,2

When an adult just emerges from its pupal skin, it is very vulnerable as its body is still soft and flexible. It thus remains in a cell it creates in the soil for days up to two weeks (depending on the environmental conditions), during which its body cuticle hardens and becomes fully pigmented, before it digs it way out of the soil.¹Despite spending almost 10 months in the soil, the Japanese beetle has a short lifespan, which is only 30 to 45 days.⁵

A Beetle’s Fault

Knowing so much about these beetles’ behaviors, like defense, flight, feeding, etc., and having learnt so much about these insects’ lifecycle, from where they were laid as eggs to how they finally become an adult, you may think that these beetles have short but interesting lives. Wouldn’t you think of the beetles as some lovely little beings that you would be delighted to spot on your plants?

But most people are thinking the exact opposite. The reason behind is simple, and it all started in the early 20^th century, when there was probably someone carrying iris bulbs with Japanese beetle grubs in the soil, entering the U.S.¹⁰ Since then, this attractive and colorful-looking creature has become an invasive species, a destructive agricultural pest, a vile enemy to the farmers and the economy in the North America.

Think of its biology again, and it is not hard to figure out how the Japanese beetle has become such a destructive invader. Their grubs spend nearly a year under the soil, where humans can hardly spot or catch, eating and damaging the roots of crops. They grow up to continue consuming commercial crops, oviposit there, and the cycle repeats. Even if farmers change the type of crops, they can still easily survive since they feed on a wide variety of plants. Worse still, they can disperse by flight, meaning that they can spread quickly to infect new areas.

Man vs. Beetle

And that was what happened in reality. First found in New Jersey in the U.S. in 1916, the Japanese beetle has spread so widely, to the extent that half the country had cases of infestations in 2015, and its larval stage alone have already contributed to a loss of around USD234 million per year.⁹ It has also spread to other countries like Canada, and even to European countries such as Belgium and Portugal, affecting both economic and non-economic species like fruits, vegetables, herbs and trees.¹⁰ Common plants that are affected includes maize, soybean, grape, raspberry, roses, maples, etc.^1,10

Because of these damages, people have been developing various methods to eliminate the Japanese beetles. These include physical removals like traps, exclusion, removal, etc., chemical controls such as repellents and pesticides, and biological controls using pathogens and parasites. The Japanese beetles actually do have natural predators, which are mostly ants, ground beetles and some generalists, who eat their eggs and grubs, and also some birds and small mammals.¹⁰ However, these predators are seemingly not very successful in regulating the population of the invasive beetle, and some of the predators like moles and racoons will also damage pastures, which makes them not ideal for controlling the beetles.¹⁰

So, instead of using predators, pathogens and parasites are often artificially applied, with the nematode Heterorhabditis bacteriophora, soil bacterium Bacillus thuringiensis, and spores of the bacterium Bacillus papillae being more commonly used and commercially available. Nematodes, the parasitic roundworms, works by penetrating into a grub and introduce the grub with a bacteria species that feeds on the grub’s body tissue, and the nematode will then eat the bacteria.⁹ Being the food of the bacteria and the nematode, the grub will eventually die. The beetles’ grub stage can also be controlled by the soil bacterium, which basically works by producing toxins to poison the grubs.⁹ The third control is by the spores of B. papillae, which will germinate in the grubs’ gut when they are ingested, infecting the gut cells and killing the grubs.⁹

End of story?

Although there has been a lot of effort in eliminating these Japanese beetles, the spread of such a tough invasive species can hardly be stopped. In 2017, the Japanese beetles have crossed the border again and spread to Switzerland, most likely from the border of Italy’s natural park where a population of Japanese beetles had been established.¹¹ Obviously, the battle against the beetle is to be continued.

And that is the story of Popillia japonica, the Japanese beetle that has changed from an insect that nobody cared much, to a subject of research focus in entomology; from a small living being, to a big bad villain, in just all of that one sudden in 1916. That was the year when its colorful combination of metallic green and copper brown no longer reminds people to appreciate the beauty of nature – but to remove the pest, and not to forget to spray pesticides, apply parasitic nematodes, soil bacteria, and bacterial spores…

References

Fleming, W.E. (1972). Biology of the Japanese Beetle. United States Department of Agriculture Technical Bulletin, No. 1449.
Canadian Food Inspection Agency. (2017). “Popillia Japonica (Japanese Beetle) – Fact Sheet.” http://www.inspection.gc.ca/plants/plant-pests-invasive-species/insects/japanese-beetle/fact-sheet/eng/1328165101975/1328165185309
Potter, M.F.; Potter, D.A.; Townsend, L.H. (2006). “Japanese Beetles in the Urban Landscape.” https://entomology.ca.uky.edu/ef451
Hodgson, E.; Alston, D; Stanley, C.A. (2010). “Utah Pests Fact Sheet – Japanese Beetle (Popillia japonica).” https://digitalcommons.usu.edu/cgi/viewcontent.cgi?referer=&httpsredir=1&article=1918&context=extension_curall
Hadley, C.H. (1934). General Information about the Japanese Beetle in the United States. United States Department of Agriculture Circular, No. 332, p23.
Metzger, F.W. (1934). Traps for the Japanese Beetle and How to Use Them. United States Department of Agriculture Miscellaneous Publication, No. 201, p12.
Major, R.T. & Tietz, H.J. (1962). Modification of the resistance of Ginkgo Biloba Leaves to Attack by Japanese Beetles. Journal of Economic Entomology. Vol. 55, p272.
Fleming, W.E. (1958). Biological Control of the Japanese Beetle, Especially with Entomogenous Diseases. 10^th International Congress Proceedings, p115-125.
United States Department of Agriculture Animal and Plant Health Inspection Service. (2015). Managing the Japanese Beetle: A Homeowner’s Handbook.
Invasive Species Compendium. (2018). “Datasheet – Popillia japonica (Japanese beetle)”. https://www.cabi.org/isc/datasheet/43599
European and Mediterranean Plant Protection Organization Global Database. (2017). “First report of Popillia japonica in Switzerland.” https://gd.eppo.int/reporting/article-6128

Author: Star Bugs

A pretty special damselfly—Pseudolestes mirabilis Kirby, 1900

1. Species information

Figure 3. (A) Dorsal and (B) ventral view of larvae of P. mirabilis (©Xin Yu, permitted to use)

After a boring and prim introduction of this species, let’s start the really interesting and exciting part!

What is P. mirabilis ?

Longely species

Special ‘scales’ in hindwings

Beautiful ‘dancing’

‘Common’ or ‘rare’?

References

Lovely but Tricky – Ant-mimicking Jumping Spider Myrmarachne magna

Plexippus paykulli – The Evil Spiderman

Chestnut Tiger: Not a chestnut nor a tiger

Scutigera coleoptrata – More Than Just a Horrifying Appearance

Monstrous organ of beautiful moth: The mysteries of Creatonotos gangis’s coremata

“Is this a monster in a horror movie?”

Figure 1 – The mysterious, hairy and massive organ that impressed many people.Source: David Smiley. (2014). Coremata. BunyipCo. Retrieved from:http://bunyipco.blogspot.com/2014/08/coremata.html

Figure 2 Some people think Creatonotos gangis is as weird as the monster in “Godzilla” movies. Draw by: Mak Hin San Paul (2018)

Coremata – the important tool for seeking love

Figure 3 The appearance of Creatonotos gangis with no inflated coremata. Photograph by 吳子健Source: Dearlap.tw. Retrieved from: http://dearlep.tw/species.html?namecode=343822&photo_id=2f00563786b43a31015f5d4d26e773f2

Figure 4 The scent scales on the coremata can erect and release the pheromone. Source: Davenport, J. W., & Conner, W. E. (2003). Dietary alkaloids and the development of androconial organs in Estigmene acrea. Journal of Insect Science, 3(1), 3.

More stories behind the coremata of Creatonotos gangis

Figure 5 Coremata might swell and erect to horrify rival creatures. Source: David Smiley. (2014). Coremata. BunyipCo. Retrieved from: http://bunyipco.blogspot.com/2014/08/coremata.html

Scientific Terminlogy (Not explained in the article)

Reference

Cyrtotrachelus longimanus – the elephant on the bamboo plant

Just Mimics or Something Much More? – The Orchid Mantis (Hymenopus coronatus)

More to the point, do they even look like flowers to other insects?

Believe it or not, it wasn’t until 2013 that the first paper describing the distinctive characteristics of the orchid mantis in scientific detail was published! ⁸

Not satisfied with just a superficial description, the team went on to put several commonly held beliefs to the test, with surprising results!

Instead, the orchid mantis actually attracts pollinators to itself BETTER than real flowers!⁷

Indeed, it seems that the more we look into the species, the more we find left to discover and study!

In short, as charismatic and captivating H. cornonatus may be, they remain critically understudied.

Remember: looks can be deceiving, so never judge a book by its cover… or in this case, a bug by its color!

The False Accusation of a Century – Gryllotalpa africana, de Beauvois

The Attractive Beetle that Nobody Praises – Popillia japonica (the Japanese beetle)

1. Species information

Figure 3. (A) Dorsal and (B) ventral view of larvae of P. mirabilis (©Xin Yu, permitted to use)

After a boring and prim introduction of this species, let’s start the really interesting and exciting part!

What is P. mirabilis ?

Longely species

Special ‘scales’ in hindwings

Beautiful ‘dancing’

‘Common’ or ‘rare’?

References

“Is this a monster in a horror movie?”

Figure 1 – The mysterious, hairy and massive organ that impressed many people.Source: David Smiley. (2014). Coremata. BunyipCo. Retrieved from:http://bunyipco.blogspot.com/2014/08/coremata.html

Figure 2 Some people think Creatonotos gangis is as weird as the monster in “Godzilla” movies. Draw by: Mak Hin San Paul (2018)

Coremata – the important tool for seeking love

Figure 3 The appearance of Creatonotos gangis with no inflated coremata. Photograph by 吳子健Source: Dearlap.tw. Retrieved from: http://dearlep.tw/species.html?namecode=343822&photo_id=2f00563786b43a31015f5d4d26e773f2

Figure 4 The scent scales on the coremata can erect and release the pheromone. Source: Davenport, J. W., & Conner, W. E. (2003). Dietary alkaloids and the development of androconial organs in Estigmene acrea. Journal of Insect Science, 3(1), 3.

More stories behind the coremata of Creatonotos gangis

Figure 5 Coremata might swell and erect to horrify rival creatures. Source: David Smiley. (2014). Coremata. BunyipCo. Retrieved from: http://bunyipco.blogspot.com/2014/08/coremata.html

Scientific Terminlogy (Not explained in the article)

Reference

More to the point, do they even look like flowers to other insects?

Believe it or not, it wasn’t until 2013 that the first paper describing the distinctive characteristics of the orchid mantis in scientific detail was published! 8

Not satisfied with just a superficial description, the team went on to put several commonly held beliefs to the test, with surprising results!

Instead, the orchid mantis actually attracts pollinators to itself BETTER than real flowers!7

Indeed, it seems that the more we look into the species, the more we find left to discover and study!

In short, as charismatic and captivating H. cornonatus may be, they remain critically understudied.

Remember: looks can be deceiving, so never judge a book by its cover… or in this case, a bug by its color!

Believe it or not, it wasn’t until 2013 that the first paper describing the distinctive characteristics of the orchid mantis in scientific detail was published! ⁸

Instead, the orchid mantis actually attracts pollinators to itself BETTER than real flowers!⁷