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Phalces brevis (Cape Stick-insect)

[= Phalces longiscaphus, Phalces coccyx]

Life > Eukaryotes > Opisthokonta > Metazoa (animals) > Bilateria > Ecdysozoa > Panarthropoda > Tritocerebra > Phylum: Arthopoda > Mandibulata > Atelocerata > Panhexapoda > Hexapoda > Insecta (insects) > Dicondyla > Pterygota > Metapterygota > Neoptera > Polyneoptera > Anartioptera > Orthopterida > Phasmida (stick and leaf insects)

 

Phalces brevis male.

[photo by P. Brock ©]

Phalces brevis female, on Rhus sp. [photo by HG Robertson, Iziko ©]

Description

Male 50-55mm, female 70-80mm. Very stick-like, medium sized wingless insects with short antennae. The male is greenish brown, with three bluish green marks and white bands on the pronotum, hind part of the mesonotum and metanotum (useful to distinguish it from the similar male of Macynia labiata). The legs are green with a brown base and apical band on all femora. The cerci are whitish. Females are usually brown or grey, perhaps speckled; occasionally they are green. The abdomen ends in a boat-shaped chute-like appendage, which varies in length. However, it is often around four times the length of the anal (last abdominal) segment.

Life History and behaviour

Females drop their glossy eggs to the ground. The resulting nymphs moult five times, taking about 4-6 months to mature; adults live 4-6 months. Each female usually lays a few hundred eggs. Adults remain well concealed in the daytime, often moving away from their foodplants, only to return at night.

When disturbed, nymphs may sway from side to side. Bisexual reproduction is by means of a spermatophore (sperm sac), although they can reproduce parthenogenetically. Certain ants are attracted to eggs, which they carry to their nest by the capitulum (knob on the lid of the egg). The capitulum is removed and eaten without reducing egg viability.

 

Phalces brevis pair mating.

[photo by HG Robertson, SA Museum ©]

Foodplants

In the Cape Town area on Leptospermum laevigatum, Erica aemula, Podocarpus sp., Rhus spp., Passerina spp., Rubus fruticosus and Liparia splendens. They also accept a wide range of plants in captivity.

Distribution

Very widespread in the Cape Province, South Africa. Also reported from Natal.

References

  • Brock, P.D. 2000a. Studies of the genus Phalces Stål. Phasmid Studies 8: 1-8.

  • Brock, P.D. 2000b. Stick-insects (Phasmida) from the Cape Town area, South Africa. Bulletin of the Amateur Entomologists’ Society 59: 2-13, pl. 00A-D.

  • Compton, S.G. & Ware, A.B. 1991. Ants disperse the elaiosome-bearing eggs of an African Stick Insect. Psyche 98(2-3): 207-213. [the species featured in this paper Bacillus ?coccyx is now known as Phalces brevis].

Text by Paul Brock ©