|This article does not cite any references or sources. (February 2007)|
|Carausius morosus from India|
Carausius morosus (the 'common', 'Indian' or 'laboratory' stick insect) is a species of Phasmatodea (phasmid) that is often kept by schools and individuals as pets. Culture stocks originate from an original collection from Tamil Nadu, India. Like the majority of the Phasmatodea, they are nocturnal. Culture stocks are parthenogenetic females that can reproduce without mating. There are no reports of males, although in captivity, gynandromorphs (individuals with both female and male characteristics) are sometimes reared.
Females are elongated and about 80–100 mm in length, ranging from a light green to a darkish brown in colour. The front legs have red patches at the base of the forelegs, and similar but yellow patches on the mid-legs. Eggs are ovoid and brown, with a beige plug at one end. When the eggs hatch, the plug opens and dark, tiny, string-like young crawl out of the opening. The eggs are haploid.
When disturbed, the major defence method is feigning death, the body becoming rigid, and the legs held along the line of the body. Other times, they may be found swaying to mimick the movement of foliage in wind.
Feeding occurs at night, when the insects are active. During the day, they rest (often with legs in line with the body) on their food plants.
When excited, the Carausius morosus can be found adopting a handstand position on its two front legs. Under good light (daylight) and with a handheld magnifying glass you will also be able to note a smile on the stick insect's face, and colouring which mimics a blush. If this behaviour is detected, please try to record using digital media, as to date there remains no official record of this phenomena.
Care in captivity
This is an easy species to rear, feeding on fresh privet, ivy or bramble. They need to be kept in a cage around 25 cm in height to allow for successful moulting. Females will lay eggs shortly after reaching adulthood, at the rate of several per night. These can be hatched by keeping them on dry paper towel, or in a dry dish. Eggs can take four months to hatch, depending on many factors, including temperature. This is species number one on the Phasmid Study Group Culture List.
Accidental introductions have been recorded around the world, including South Africa, Great Britain and the USA. The last has been more problematic than most, with many reports from gardeners of the insects reaching pest proportions, especially in Orange County.[clarification needed]