''Carausius morosus'' (the 'common', 'Indian' or 'laboratory'

stick insect The Phasmatodea (also known as Phasmida, Phasmatoptera or Spectra) are an order of insects whose members are variously known as stick insects, stick-bugs, walking sticks, stick animals, or bug sticks. They are also occasionally referred to as ...

) is a species of

Phasmatodea The Phasmatodea (also known as Phasmida, Phasmatoptera or Spectra) are an order of insects whose members are variously known as stick insects, stick-bugs, walking sticks, stick animals, or bug sticks. They are also occasionally referred to as ...

(phasmid) often kept as pets by schools and individuals. Culture stocks originate from a collection from

Tamil Nadu Tamil Nadu (; , TN) is a States and union territories of India, state in southern India. It is the List of states and union territories of India by area, tenth largest Indian state by area and the List of states and union territories of India ...

, India. Like the majority of the Phasmatodea, ''C. morosus'' are

nocturnal Nocturnality is an animal behavior characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnal meaning the opposite. Nocturnal creatures generally have highly developed sens ...

. Culture stocks are

parthenogenetic Parthenogenesis (; from the Greek grc, παρθένος, translit=parthénos, lit=virgin, label=none + grc, γένεσις, translit=génesis, lit=creation, label=none) is a natural form of asexual reproduction in which growth and development ...

females that can reproduce without mating. There are no reports of males, although in captivity,

gynandromorph A gynandromorph is an organism that contains both male and female characteristics. The term comes from the Greek γυνή (''gynē'') 'female', ἀνήρ (''anēr'') 'male', and μορφή (''morphē'') 'form', and is used mainly in the field ...

s (individuals with both female and male characteristics) are sometimes reared.

Description

Females are elongated and about 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 in length,

ovoid An oval () is a closed curve in a plane which resembles the outline of an egg. The term is not very specific, but in some areas (projective geometry, technical drawing, etc.) it is given a more precise definition, which may include either one or ...

and brown, with a beige capitula 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 Ploidy () is the number of complete sets of chromosomes in a cell, and hence the number of possible alleles for autosomal and pseudoautosomal genes. Sets of chromosomes refer to the number of maternal and paternal chromosome copies, respectively ...

Behaviour

When disturbed, the major defence method is feigning death, the body becoming rigid, and the legs held along the line of the body. They may also be found swaying to mimic the movement of foliage in wind. The insects feed at night, when they are active. During the day, they rest, often with legs in line with the body, on their food plants.

Accidental introductions

Due to their inconspicuous nature, accidental introductions of ''C. morosus'' have been recorded around the world, including

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South Africa South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring countri ...

and the United States, where in some cases they have become a pest. Studies at

San Diego Zoo The San Diego Zoo is a zoo in Balboa Park, San Diego, California, housing 4000 animals of more than 650 species and subspecies on of Balboa Park leased from the City of San Diego. Its parent organization, San Diego Zoo Wildlife Alliance, is a p ...

found the introduced species on a large number of ornamental plants.

References

{{DEFAULTSORT:Carausius morosus Lonchodidae Insects described in 1901 Insect rearing