The full version can be read in Newsletter number one
Captive Husbandry of Idolomantis diabolica, the Devil Flower
Gary Symes and Craig Smith
Common names: Devil Flower, until recently African Devil Flower, Greater Devil Flower mantis.
Distribution: East Africa: Ethiopia, Kenya, Malawi, Somalia, Tanzania, Uganda.
Natural habitat: Semi moist savannah grasslands, light scrubland.
Adult male Idolomantis diabolica in deimatic display.
Photograph by Gary Symes
Idolomantis diabolica, or the Devil Flower as it is more commonly known, is an impressive and desirable insect for every mantis keeper. It is not the longest, heaviest or even prettiest mantis, but with its overall adult size, bizarre shape and beautiful colouration it is on the “wish list” of every mantis enthusiast and rightly so. Devil Flowers were a misunderstood mantis and because of this people found them very hard to raise and breed in captivity. The Germans were probably the first to breed them for successive generations with stock that is still in culture today, the IGM25 stock from the Mara/Mwanza region in Tanzania, imported in 2004. The Americans have had some success too in 2007. In the UK we have also had our successes and several of us have raised and bred the Mara/Mwanza line for at least two generations. There are some noticeable differences in successful husbandry methods for Idolomantis compared to other species. We present here our husbandry techniques, observations and records of I. diabolica (Tanzanian stock IGM167) in an effort to help other Devil Flower worshippers have as much, or more, success with this legendary insect.
An Idolomantis diabolica ootheca with recently hatched nymphs. Hatches from 10 to at least 50 nymphs have been recorded.
Photograph by Gary Symes
The oothecae of Idolomantis diabolica are well insulated against extremes of temperature and humidity and because of this they do not need any special care other than a temperature of between 27oC-32oC during the day with a drop at night to 18oC-27oC. Incubation varies from around 30 days to as long as 60 days at more extreme high temperatures.
When an ootheca hatches in less than ideal conditions (temperature higher than 36oC, relative humidity levels lower than 40%), there is a good chance that the emerging nymphs will become stuck and quite probably die. We have observed that at higher incubation temperatures some oothecae have taken nearly twice as long to hatch. We speculate that the lower humidity levels at high temperatures have some part to play in this, and the hatch may be waiting for more favourable conditions to commence.
First instar nymphs are very large and will easily feed on house flies and curly wing flies as well as on fruit flies. They have been known to take green bottle flies and even blue bottles as first instars but these are extreme measures and you should aim to provide them with nothing bigger than house/curly wing flies as hatchlings.
Nymphs also quite happily take crawling insects such as roach and locust nymphs and small mealworms, although this will tail off towards fourth and fifth instar and flying insect prey will then make up nearly all of their preferred food. They will still take crawling insects on occasion as they grow and mature, especially if very hungry. It is possible to fool them into taking non-flying prey, such as adult roaches, if flies are scarce, by offering the prey on tweezers, held by a wing tip and “whizzing” past their faces a few inches away.
As with all mantids, first instar nymphs are at their most delicate and care should be taken not to subject them to extremes of temperature or humidity. Generally Idolomantis diabolica are pretty resilient, even as first instars. As older nymphs they are extremely tolerant and can rapidly and successfully moult in what could normally be considered to be quite hot and dry conditions. However we have had greater success and faster growth from giving the enclosures a good spray to a drenching every evening. This should evaporate within an hour in a well ventilated enclosure but the substrate should hold some moisture to disperse into the mantids’ environment for considerably longer. It should also be noted that kept very dry they may aestivate, lack of food will also exacerbate this, staying in their present stadium until conditions are more favourable again.
Idolomantis diabolica females can reach at least 12 cm in length.
Photograph by Gary Symes
Under ideal conditions Idolomantis diabolica grow fast, considering their overall size, and can be adult in 4 months. From 1st instar, males will mature in 7 moults and females in 8 moults. Moulting has never been a problem for this species provided they have the right “perch” material. As with every other species they will need an enclosure with enough height to allow them to exit the old exuvium (skin). This at minimum should be two and a half times the mantid’s length in height, ideally three times the height of the animal’s length. Sometimes mantids do not moult from the tops of their enclosures! Also, in case of moult slips it may be advantageous to provide a soft deep moisture retaining substrate, this will cushion the mantis if it should fall and do less damage to it, and you may be able to rescue it.
As with most mantids, on occasion they like to bask in the sunlight. Idolomantis diabolica seem to love to bask, whether this is for the extra heat or the UV light they would get from the sun is unclear. Given a spot lamp they will sit under it for hours, moving in and out of its beam as and when needed, much like a lizard thermo-regulating.
As mentioned above, Idolomantis diabolica will take suitable crawling insect prey in their lower instars, sometimes even older instars will too, but mostly they want flying prey. Fruit flies, houseflies/curly wing flies green bottle and blue bottle flies are all recommended. Devil Flowers can be fed exclusively on bluebottles as adults but it takes a staggering amount to fill the females up, which you will want to do to prevent female/male cannibalism that might occur as her appetite increases to cope with the demands of egg maturation.
We have also used silk moths, cabbage white butterflies (collected from caterpillars on cabbage plants or nasturtiums) and wax moths as prey. Bees and wasps will be taken with gusto but bees at least are in decline and should be left alone. Blue bottle flies are probably the best way forward as they can be bought in huge numbers very cheaply from fishing tackle shops. Try to buy them as white maggots rather than pupae as the latter may not hatch.
As small nymphs they are easy to house using polystyrene cups. The polystyrene affords good grip allowing the two tarsal claws to easily sink into polystyrene. The cup walls slope inwards allowing nymphs to use gravity to assist the moult and a good grip from all six feet on a sloped wall rather than vertical one should anything go wrong
For photographs see the full article in the newsletter
A modified polystyrene box (left) and a custom made wood-mesh cage (right). Photographs by Gary Symes and Craig Smith respectively.
Cages are a matter of choice but some good examples are as follows: framed net insect cages (custom made or commercial), rough cut wooden boxes with net framed doors (custom made), aquariums lined with polystyrene or balsa wood and a framed net lid.
Idolomantis diabolica can be kept communally in net cages but be aware that they can be cannibalistic, just like other species, and they are totally vulnerable to attack when moulting. Often two mantids will grab the same fly, which can result in loss or damage of limbs, or death of one or both individuals. Large numbers of mantids require large numbers of flies, which can be a hazard to a moulting mantis, so be aware of this in your chosen set up.
Good results have been achieved by removing a mantid from the communal cage prior to moulting and giving it an empty net cage to moult in, a 30.5 cm x 30.5 cm (l & d) x 38 cm (h) cage is ideal. This prevents any accidents happening during moulting and gives the mantis time to fully harden up away from other mantids.
After 4 to 6 weeks fully mature adults will be ready for breeding. Females will often be seen “calling”, lowering the tip of the abdomen and raising their wings slightly to expose more of the uppermost side of the abdomen for pheromone release. Males can be kept separately from females to prevent cannibalism that, although not as common as with other species can still happen. Adult males and females can also be kept together as the males do not become desensitised to the females mating/attracting pheromone. Often all that is needed is a very good drenching of the enclosure to get them pairing up.
Requirements for successful captive husbandry
Idolomantis diabolica were thought to be a tricky species to rear. Their reputation for difficulty probably arose from incorrect husbandry as the special requirements of this species were not known. Providing flying food is one of the key requirements for success. Flies, from fruitflies to bluebottles, are easy to acquire in large numbers and with a little experience they can be cooled and stored for maximum usage. Giving the feeder flies some space to fly and exercise their flight muscles and offering good food, such as diluted honey and fruit juice/puree, will make them a much more nutritious food for your charges.
Housing furniture is also important for success. Moulting is easy for them as long as they are not weak or poorly kept and given the right choice of housing and perches. Provided you can give it an ideal surface to walk and moult on you will not experience any more fatalities than with any other species. Small twigs are suitable for Idolomantis diabolica, good examples are silver birch and beech twigs, also twigs with a rougher texture such as elder.