Biology of development of Cydalima perspectalis (Lepidoptera: Crambidae) in laboratory conditions

Abstract

The number of instars of the Cydalima perspectalis caterpillars when feeding on Buxus sempervirens varies from five to eight. Caterpillars of the VIII instar were found in a single specimens in each generation. The time spent at the VIII instar, both in the first and second generations, was 8 days. The pupae in both cases turned out to be males. The sex ratio during pupation at the V instar was 1:1 in both generations, at the VI instar in the first generation – 1:1.7, and in the second – 1.3:1. During pupation at the VII instar, males dominated (1:2). The maximum percentage of pupation is observed at the VI instar, which turned out to be the most common older instar in the studied individuals of the box tree moth. Caterpillars of the boxwood moth hatched from the same egg cluster and under the same conditions developed asynchronously. The duration of the caterpillar phase varied from 18 to 29 days under the same temperature. The coefficient of variability for the period of caterpillar stage in the first generation was 11.7%, in the second 13.3%. At the same time, most caterpillars of the first generation at the I–IV instars, and in the second generation – at the I–V instars developed within two to three days. Biometric indicators of caterpillars in different instars were determined. The maximum growth rates of the head capsule were observed at the III instar. Some caterpillars of the first generation at the III and IV instars formed double-layered cocoons in which they stayed for six months, been alive.