Biology and Ecology of the Phasmatodea

The Phasmatodea show a number of interesting features. More than 2500 species are known; some of them are very large in size and many have a remarkable resemblance to sticks or leaves. All feed on plants. Parthenogenesis can occur in a number of species, and some species living in temperate zones often undergo an obligatory diapause in the egg stage during winter to enable the organism to escape unfavorable conditions. Although usually difficult to find in the field because of their camouflaged appearance, some species nevertheless occur periodically in large out­ break populations and become pests of natural forests or plantations. Their defen­ sive behavior may include catalepsy or death feigning, procrypsis or concealing coloration, conspicuous wing displays, metathoracic leg movements, and defensive secretions. For decades Carausius morosus has been a well-known laboratory ani­ mal, and more recently other species have been bred in England and Europe for experimental and educational purposes (27, 30). The publications of Beier (10, 11) and Chopard (25, 26) deal with the external morphology and anatomy of the order and list other publications. The most recent review of classification and zoogeogra­ phy is by Gi.inther (54), in which two families are recognized: the Phylliidae, with
8 subfamilies; and the Phasmatidae, containing 11 subfamilies.