It’s morning in a Malaysian rainforest; a thin fog layer is starting to evaporate as the air become drier. Some small Sphingidae butterflies are visiting “street rhododendrons” all along the bare patches in the forest. One of them sees a particularly big inflorescence, a strong attraction to the hungry insect, and close to the flower turns and hovers. Suddenly, the butterfly is reached by two white, deadly raptorial legs and taken to the munching jaws. Hiding behind the flower petals there is a “Kanchong”, as Malaysian natives call orchid mantids. They say that these insects are so well camouflaged that just a few men have managed to see more than one in all of their lives.

Hymenopus, commonly known as the orchid mantis, is one of the most beautiful mantids available from breeders. Even though it is not very big its colours, unusual shape and behaviour are a big attraction for anyone. Adult female can reach 6-7 cm while males are much smaller, around 3.5 cm. They live in tropical rainforest in Indonesia, Malaysia and Brunei.

Description, hunting and defence.

When just hatched they are red-orange with black-blue legs and head. They look similar to ants and some Reduvidae (assassin bug) nymphs, both of which are quite distasteful and often ignored by many vertebrate predators and spiders. After their first moult they usually turn translucent white with shades of a pinkish hue. It’s possible to find completely pink individuals and there seems to be some environmental or seasonal reason for this but, as far as I know, colour patterns are not completely understood (see below). They also develop particular flat expansions on the femora and have large, sharpened violet-grey eyes. Like most mantid nymphs, they keep the abdomen curved up over the back.

In its natural habitat the insect sits quietly on flowers, waiting for prey but it also employs many tricks in order to survive, more than one would at first suppose. That white/pink pattern matches many common flowers in the tropical rainforests but the shape is not similar to any flower in particular. The mantis seems to just display a general flower-like resemblance, which allows it to escape capture and to hunt effectively. According to Annandale, they are usually found on Melastoma polyanthum, commonly named street rhododendron by him. Since I wasn’t able to find this plant I depicted them on a Phalaennopsis sp. orchid from tropical South-East Asia. The orchid mantis has a small green band across the thorax which is a useful decoy, breaking up the mantid outline into two different parts, making it resemble two separate flowers. Many keen-sighted animals are often confused this trick, man included.

Over the head, between the eyes, there is a small horn, which simulates a flower’s reproductive apparatus. The prey insects, mostly flies and other diptera, are taken while visiting this “flower”. There is also a dark spot in the last part of the abdomen, near the anus. It was demonstrated that this attracts small flies which mistake the spot for an individual of the same species foraging on a flower. A large number are attracted this way, but they sometimes they are not taken by the mantis due to their small size. Bigger species are lured by the abundance of other smaller insects and are immediately captured.

Another feature is the many longitudinal brown stripes along the upper side of the abdomen. These structures are very similar to orchids’ “honey guides” and are directed toward the thorax of the mantis. Some insects are attracted this way but usually the dorsal abdomen is not visible in the rest position.

According to other studies, Hymenopus sometimes hunts among green foliage. Here the colour and shape look really conspicuous, but the mantis is still investigated by various flower-seeking insects. This theory is confirmed by the fact that white, pink or yellow objects, even pieces of paper, positioned on plants attract various Diptera and Lepidoptera. It seems the very famous Idolomum diabolicum, the “devil’s flower mantis” from Africa, uses a similar ambush tactic, mimicking a flower with its big colourful thorax. In common with Hymenopus, this species also exhibits a series of small black spots, resembling flies feeding, on its abdomen. Hymenopus can track flying targets with excellent accuracy and sometimes take insects during manoeuvres or landings.

When moving slowly, these mantids employ a characteristic swinging movement, similar to a plant being blown by a weak breeze. When a prey item is not within reach, and the mantis is hungry, it will try to close the distance in this way, hopefully without being detected. Although it takes several seconds to cover a single centimetre, the insect remains blissfully unaware of the presence of the mantis moving so stealthily. If necessary the mantis can move at very high speed for a short distance. They also have a limited ability to jump while threatened. The jump is not very high but adequately serves the purpose of avoiding predation.

When the mantis is on the ground, particularly on a green or brown substrate, it is extremely visible but can still be easily misidentified as a fallen flower by an inexperienced observer. When in danger young specimens sometimes assume a particular position, lowering the body to the substrate, keeping femoral expansion close to the ground and stretching forward the raptorial legs while keeping them in the classic praying position. The abdomen is also flattened and held perpendicular to the ground. By adopting this posture, any resemblance to a living creature is lost. I have also seen smaller specimens that are able to play dead (Thanatosis), the males normally being more inclined to behave in such a way. As the legs are held straight along the body and the head is pointed forward, the animal can be easily handled without offering any resistance. If left alone it will resume its normal position.

Keeping orchid mantids in captivity.

It must be said these mantids are not too easy to keep. They do best kept at 25 degrees Centigrade, with high humidity (around 80-90%), especially when younger. Ventilation is also very important.

Remember to feed the juveniles frequently; like most mantids they have a good appetite. Ideal prey items are fruit flies and, later, flies. Flying insects are the natural targets in their habitat. For variation, give them crickets, mealworms and waxworms. The flies should be always well fed, preferably with milk and sugar or, better, honey to mimic the diet of pollinating insects.

The mantids should moult at about 15 days but later phases take a little longer, with the final stage taking almost a month. A tall container should be provided, at least three times the length of the animal, and fine netting should be provided above to allow the insect to have a firm grip while moulting. Mantids with foliage appendices are quite prone to becoming entangled in the old skin if ideal conditions are not met.

The last moult takes a considerable long time, especially for females as a great amount of energy is spent for the production of those big white wings. The male matures faster and starts to display a slightly different coloration and big wing buds the moult before adulthood. You should be able to determine the sexes by counting the abdominal segments after second or third moult. Females have six and males have eight. Remember to check this on well-fed mantids only (from above ). As mature nymphs, males have a slightly different coloration with more brown and less pink.

Females take about four-to-five months to reach adult stage while males take about three-and-a-half. It must be said that growing rate can vary a lot, depending on temperature and feeding. Sometimes mantids mature in a very different time scale, without any apparent reason.

One of the most impressive features of this orchid mantis in the adult stage is sexual dimorphism; the male is in fact very different in size and colours. First of all it’s only 3 cm long, almost half of the female size. It also loses part of the white-pink coloration, turning to beige-brown in the proximity of the joints and body extremities. It remains quite active and nervous, with a good disposition to fly. Females are about 6-7 cm long, with very big wings surpassing the abdomen by more than 1 cm. Other cryptic adaptations are maintained, even if colours start to fade a little, and wing sides become brown after some time. The nymphs are more spectacular for sure and many find adults a disappointment. Adult specimens display a reduced ability to jump, but both sexes can both, even if they need ideal take-off conditions.

In my observation, adult Hymenopus are not great feeders. They seem to prefer flying prey and need prey variation to thrive (see above ). If you have problem finding food offer mealworms (they are easy to find in any specialised shop), but do bear in mind that this mantis probably won’t take them. You should present the food with tweezers to make it move, or simply put a wounded worm in the specimen’s mouth. As mentioned before, well-fed flies, butterflies and moths are probably one of the best choices.

Reproduction.

The difference between male and female maturation makes Hymenopus difficult to reproduce. Sometimes the males will be dead or useless at the time the female is ready. It is better to try to slow male’s growth, while speeding up the female’s. Usually you should feed males less and keep them in a cooler environment. Another choice is to get hold of two different batches of animals, ideally spaced by one or two moults. If you are lucky enough to find the animals at these different stages you should end up having mature males and females at the same time.

Two weeks after the insects reach adulthood, mating can be attempted. If you want to see if they are ready and receptive house male and female into separate adjacent terrariums, and observe their reactions. A receptive male should soon show interest. It is safer to introduce the female into the male’s cage; this way the smaller male will see the female first and choose his strategy. I think the ideal cage size for mating is 30 x 20 x 20 cm, with branches and leaves to provide shelter for an escaping male. Remember, both specimens should be well-fed. As soon as the male sees his mate, he can sometimes start a courtship display with his raptorial legs but he will usually try to approach her stealthily form behind. Females are usually not aggressive toward their partners, but you should always be cautious. To make the female move and keep her busy you can feed her while the male is close to give him a better chance.

To copulate, the male will climb slowly onto the female’s back, drumming with his forelegs on her wings to announce his presence. Although this is the common mating position among many insects, the great size difference in the sexes makes their copulation quite a curious event to see.

After some weeks, the female produces an egg case. This delay can vary a lot, from two to eight weeks, maybe more. In my experience the egg case is quite small and thin and should be suspended upside down in a small terrarium. According to other sources it can be bigger and contain up to 100 nymphs. Maybe captive individuals produce less eggs because of their less varied and nutritious diet. Remember to provide ideal condition for the egg case, especially humidity. Ventilation is also important; otherwise you will lose eggs to fungi. Maturation is achieved in two months (still depends on environmental conditions) and in my experience about 20-30 nymphs emerge. The body is about 5mm, with orange-red and black coloration, but they will turn white after the first moult, as mentioned before.

Males live for about two to three months as adults, but sometimes females can reach a year and over (complete life span). A friend of mine had a female who lived for fourteen months. Hymenopus are not very common on the pet market and most of the time they need to be booked, since they are very sought after. They are also very expensive. It is possible to obtain them as nymphs from various dealers, mainly in England and Germany.

Are Hymenopus able to change colour?

I was very intrigued by this matter. According to some text ( Fogden, M., and P. Fogden. 1974. Animals and their colours: camouflage, warning coloration, courtship and territorial display, mimicry. ) “they can also become pink or white, depending on the colour of the flower on which it rests”. So, I planned a small experiment. I took four of my small L-3 ( third instar ) nymphs and placed them in separate containers. The containers were about 10 cm high and 6 cm wide. On top of them I placed a plastic lid to provide good ventilation for the mantid and a firm grip while moulting. I then placed some pink band inside each container. Two of them were light pink and the other dark pink. All mantids were kept at the same temperature (about 24-27 C), with a light drop at night. I was expecting them to change colour after some time to gradually match the one prevailing into their cage but it must be said that in some months nothing happened. As they grew I placed them in bigger containers, while retaining the coloured stripes. Before turning to adulthood I stopped the experiment without achieving any colour change. I think these adaptations must be related to some environmental changes I didn’t reproduce, or they are simply genetic and typical of some population in their country of origin.

All of my specimens have always been white, some of them with more pronounced shades, but I have seen pictures of specimens which were completely pink or almost red.

Sub-adult individuals are always depicted in their natural habitat, deep in Malaysian rainforest.

Bibliography and thanks.

This article is mainly based on personal observations and the remarks of Andrea Mangoni. A special thanks goes to my friend Matias Civitella for his great help while taking pictures.

I also consulted some texts which you too may find interesting.

Annandale N. “Observations on habitat and natural surroundings of insects made during Skeat expedition to the Malai peninsula”. Proc. Zool. Soc. London. 1900.

Jope, M. “The praying mantis, keeper’s handbook”, 1998.

Prete, Wells, Hurd and others. “The praying mantids”. John Hopkins University Press, 1999.

Sharp, D. “The modification and attitude of Idolum diabolicum, a mantis of the kind called floreal simulators” Proc. Cambr. Philos. Soc., 10, 1899.

Wolfgang, W. “Mimetismo animale e vegetale ( Animals and plants mimicry ). 1968, Franco Muzzo Editore.

And lastly, take a look at these good Internet sites for some interesting picture and information.

Cedric Insect page:
http://www.kis.ch/xedric/

Insect breeding page:
http://utenti.tripod.it/latrodectus/INVERTEBRATA.htm

Mantid Study Group:
http://168.144.8.34/msg/

Terra Typica:
http://www.meos.ch/terra-typica/

Praying Mantis UK.
http://www.prayinmantids.co.uk

Francesco Tomasinelli, Piazza Manin 6-11, Genova 16122, ITALY, e-mail: giantsquid@tiscalinet.it