Order Grylloblattodea

• Grylloblatta species

Wingless insects, with eyes reduced or absent. Antennae moderately long and filamentous. Mouthparts for biting. All legs more or less similar to one another, with 5-segmented tarsi. Abdomen with a pair of long, 8-jointed cerci, and a well developed ovipositor in the female. Simple metamorphosis. This small Order includes only six described species confined to North America and East Asia. While showing some specializations, such as loss of eyes and wings, they appear to be living remnants of the stock from which both the Orthoptera (crickets and grasshoppers) and Dictyoptera (cockroaches and mantids) were derived.

Description. See illustration (opposite) of an adult female. The ovipositor between the two abominal cerci, used for egg-laying, is absent in the male.

Biology. Found in the soil and beneath stones, etc., at high altitudes of 500-2000 metres. These insects are omnivorous and nocturnal, and seem to prefer low temperatures just above freezing. The eggs are deposited singly in the soil or among moss when the adult female is about a year old. Development is very slow - there is an incubation period of about a year before the eggs hatch, followed by eight nymphal stages which together last about five years.

Distribution. Mountains of western North America.

Illustration: adapted from Walker 1914 (Canadian Entomologist 46, 93-99)