Effect of Behavioral Conditions on Silk Characteristics in the Indian Meal Moth (Plodia interpunctella)

Abstract

Lepidopteran silks are produced during the larval stage and are used for mobility and protection from predators, parasitoids, and pathogens. Our knowledge of silk structure and production in Lepidoptera is based largely on the biology of the domestic silk moth (Bombyx mori), but recent comparative evidence suggests that silk production and structure vary widely across moth taxa. Some species like the Indian meal moth (Plodia interpunctella) are becoming important biological models to study silk for its potential application to materials science and medicine, but many aspects of silk production in this species remain unknown. Here we characterize the silk of P. interpunctella by measuring the width of wandering and pupal silk strands and find that pupal silk is significantly thicker than the latter. We then report individual variation in pupal silk production in our lab-reared colony with a very small number of individuals forgoing pupal silk (< 4%) and find that overcrowding had no effect on this, whereas exposure to elevated temperatures reduced rates of pupal silk production.