Comadia redtenbacheri (Lepidoptera: Cossidae) pupal development in the laboratory

Abstract

Wild populations of Comadia redtenbacheri Hammerschmidt (Lepidoptera: Cossidae), known in its larval stage as the agave redworm, are gathered intensively for sale and consumption as food. To define adequate conditions for their pupation in confinement, the effect of handling larvae during collection, their weight when induced to pupate, substrate type and the moisture content provided during this stage of development, were evaluated over 2 consecutive yr. These factors were analyzed by logistic regression (PROC GENMOD, α = 0.05), relative to the emergence of adults. The relationship between larval weight and adult sexual gender was analyzed with a contingency table. The larvae exhibited adaptation to different substrates used for pupation, and substrates could be reused. The heavy clay content soil from areas where agaves grow, mixed with vermiculite (50:50), was the most suitable substrate (estimated value 0.7304). Moisture had no significant effect on pupation. Emergence of adults was significantly greater from larvae that had not been handled roughly as those acquired from commercial venders. According to the Chi-square test, the capacity to pupate by fifth instar larvae that weighed 0.30 to 0.39 g was not significantly different from that of the sixth and seventh instars that weighed 0.40 g or more. Males emerged mainly from cocoons produced by the smallest larvae, while females emerged mainly from cocoons by heavier larvae.