Indian Stick Insect

Carausius morosus — the Indian stick insect (also called the laboratory stick insect, Indian walking stick, or 'Carausius' to insect hobbyists) — is the WORLD'S MOST COMMON PET STICK INSECT and one of about 3,000 species in order Phasmatodea (the stick and leaf insects). The species is native to southern India (the source of the common name) but is now found in captivity worldwide and has established small feral populations in some warm regions (especially the UK Channel Islands, parts of southern Europe, parts of the southern US). Adults are 7-9 cm body length, slender brown-to-green walking sticks with the species' diagnostic features: small body size compared to many other stick insects, brown-and-green color polymorphism (color depends on background substrate during nymph development — green when raised on green vegetation, brown when raised on brown substrate), short reduced wings (Carausius are flightless), and distinctive RED EYE-SPOT MARKINGS at the base of the front legs (visible when the insect raises its front legs in defensive display). The species is the WORLD'S MOST COMMON PET STICK INSECT — kept by MILLIONS of insect enthusiasts, school classrooms, and museum education programs worldwide. The species' captive popularity comes from several features: EASY CAPTIVE HUSBANDRY (the species feeds on common houseplant leaves like privet, rose, hawthorn, oak, ivy — all readily-available leaves; the species tolerates a wide range of temperature and humidity conditions; the species lives 1-2 years in captivity providing extended educational value), DRAMATIC SIZE for arthropods (large enough to be easily observed and handled by school children), GENTLE BEHAVIOR (the species is essentially non-defensive and can be safely handled by children — it does not bite, sting, spray, or otherwise harm handlers), and OBLIGATE PARTHENOGENESIS in captivity (essentially all known captive populations are FEMALE-ONLY and reproduce by parthenogenesis without ever mating). Males are extraordinarily rare in captive populations (males have been documented at a frequency of approximately 1 in 1000 captive individuals — and even when present, captive males do not appear to successfully mate with the parthenogenetic captive females). The parthenogenetic biology makes the species one of the easiest insects to maintain in captive breeding programs — single females routinely produce dozens of viable offspring through asexual reproduction, providing self-sustaining captive populations without any need for breeding pair management. The species is featured in essentially every modern textbook discussion of insect parthenogenesis and is the foundational classroom-and-museum stick insect species worldwide. The species is harmless to humans and is a flagship example of how ease of captive husbandry can drive an arthropod species into widespread human cultural visibility.