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Stick Insects

Biology

Stick insects are insects and in many ways are similar to crickets and locusts. They have a direct life cycle for example, where the young develop as a series of nymphs which look like smaller versions of the adult. More advanced insects go through an indirect life cycle and develop via a lava and pupa. Some stick insects species make very good pet animals and are the subject of this leaflet. Pet stick insects will not infest the home if they escape and are completely harmless to humans and almost all other animals larger than themselves. Some of the best pet species are:

·        Spiny Stick Insects (Eurycantha calcarata)

·        Prickly Stick Insect (Extatosoma tiaratum)

·        Common or Indian Stick Insect (Carausius morosus)

·        Pink Winged Stick Insect (Sipyloidea sipylus)

Some other stick insects are not so good as pets. This is because they are a little tricky to rear and breed. Once some experience has been gained, however, it is quite possible to be successful with them. The species for the more experienced are: The European Stick Insects (Bacillus rossius), The Mossy Stick Insects (Orxynes macklottii), The Florida Stick Insect (Anisomorpha buprestoides) ,and the Jungle Nymph (Heteropteryx dilatata).

The types considered here are mainly tropical types that are on the whole quite large insects. Like all insects, stick insects have a tough exoskeleton and three pairs of jointed legs. As the stick insects grows it will moult its outer skin periodically. On no account should it be touched or interfered with during this process. It will cast off the old skin and the emerged stick insects will often have re-grown any legs that have been shed. The stick insects will be very soft and pale and may take a hour or two to harden off, during which time it will not feed. A space of about twice the length of the insect should be present to allow the animal to hang freely

Housing

The permanent cage needs to be quite large, 50 cm. x 25 cm. x 25 cm. Is enough for as few adults or several nymphs. The cage should be set up in a manner similar to the diagram overleaf. A heater may be installed to provide a background temperature of between 20ºC and 30ºC. This is best done with an HabiStat mat or strip taped to the inside of the back wall of a wooden cage or either side if the wall is glass or plastic. Make sure the mat acts like a radiator, so none of the surface should be obstructed. Much of the success achieved in keeping stick insects will come from the skilful manipulation of ventilation. Some of these animals require highish humidity others like it much dryer but none can stand stagnant air conditions. Fresh air moving into the cage is essential. Use the upward draughts caused by heated air rising to flush out the cage and drag fresh air in. A light misting with a hand sprayer will provide the 40% to 80% humidity required. All species will require at least one complete surface of the cage to be ventilated.

Husbandry

All types can be kept in groups, usually of a single species but sometimes, different species will also live together. Many will just sit motionless for most of the day, so plenty of perches should feature in the cage design. These animals do not really like being handled, so if it is necessary to move them, pick them up by coaxing them onto a finger without holding them. They have two basic defenses. One is to play dead and the other is to kick out with spiky legs and feet. This will give the sensation of tiny pinpricks but is not at all dangerous. If grasped the larger specimens may attempt to pinch the offending finger. They rarely break the skin. In time the cage will begin to look scruffy as debris builds up. As all the cage furnishings are washable or disposable, a good clean out is easily done. The cage set up advised in this leaflet is practicable and can be made to look pleasing to the eye. It will, of course, be necessary to periodically change the food plant as it is eaten or withers. In any case, some of the very informative books on insects in general and stick insects in particular could be investigated.

Food & Feeding

These stick insects are not really fussy about their food and will eat many plant species. The most commonly taken plant and the easiest to collect is bramble. Choose branches from a place where it is known no insecticides, herbicide or any other toxins have been used. Bramble can even be found in winter, as it remains green under the snow.

Feed the stick insects continuously with enough to be eaten in a couple of days to a week. Do not leave dead and dying food plant in the cage as it will only smell and become unpleasant. Water is usually sipped from droplets on the leaves but if fresh greenery is offered it is unnecessary to provide drinking water. A light misting may be appreciated by some species, however, as high humidity may be an essential factor. Stick insects should not be able to freely approach water, either in the container holding the food plant,  or in water dishes, they usually drown. Plug the container mouth up with extra leaves and twigs so the insects are safe.

Reproduction

To sex stick insects, both male and female specimens are initially required. Females are usually larger and more robust. Of the winged species, males have larger wings and many can fly. The females are, of course, the only sex to lay eggs. Stick insects are renowned for being able to reproduce without mating (pathenogenetically) and in some species males are quite rare. In captivity males seem more fragile than females and are often lost, thus forcing any continuation in captivity to be pathenogenetic. Breeding is not at all difficult, just leave them alone and wait for the eggs to hatch. Most eggs are dropped at random in the cage. Some species bury the eggs, so look up the details of each particular kind. Try looking on the Internet or join a club like the Phasmid Study Group to get more information.

Health & Disease

Stick insects may take several months to reach adult, it will depend on temperature, food availability and other factors. Once adult, life expectancy is usually a few more months. They do not suffer from many diseases and special attention is rarely needed. An environment and diet as described in this leaflet will preclude most problems. Good practice, hygiene and first aid will probably deal with rest. If real disease or injury is discovered, a suitable authority may of course, be consulted. Pet stick insects do not pose a real threat to human health. All the normal hygiene precautions regarding humans and animals should be observed.