Blattoidea

(also Blattoptera or Blatteria), an order of pau-rometabolous insects. The body is flat and oval, measuring 0.4–9.5 cm in length.’ The head is covered with a shield-like pro-notum and is bent, with the mouth opening down; the mouth-parts are adapted to chewing. The antennae are multisegmented and setaceous. The elytra are compact, and the membranous hind wings fold under the elytra when at rest; the elytra and wings are sometimes reduced or absent. The legs are cursorial and divided into five segments. The abdomen is elongated with 8–10 segments and has long, usually segmented cerci at the end. The ovipositor is entirely merged into the body.

Fossil Blattoidea are known from the Carboniferous period, when they apparently constituted a large part of the insect fauna. There are now approximately 3,000 species, primarily distributed in the tropics and subtropics. Fifty-five species are distributed in the USSR.

Most Blattoidea are active at night. During the day they remain hidden under stones or fallen leaves, in cracks on the surface of the soil, in rodent holes, and under the bark of tree stumps and dying trees. They feed on animal and plant residues.

Blattoidea deposit eggs protected by special capsules called oothecae. Some tropical species are viviparous. The larvae develop over periods ranging from several months (German cockroach, Blattella germanica) to four years (oriental cockroach, Blatta orientalis). Several species, including both of the above, inhabit human dwellings (seeSYNANTHROPIC ORGANISM). Blattoidea can damage food, leather goods, bookbindings, and house and greenhouse plants. Some species are vectors of infectious diseases, for example, dysentery, and may carry helminth eggs.

Control measures include dusting infested areas with insecticides, spreading bait poisoned with borax, and disinsectization of nonliving areas, such as greenhouses and libraries.