Effect of biotic and abiotic variables on silk production in the Indian meal moth (Plodia interpunctella)

Lepidoptera use silk for many purposes, ranging from cocoon construction and protection from predators to prey capture. However, research on lepidopteran silks has been limited to model organisms, such as the silkworm (Bombyx mori). Recently, silk research has expanded to focus on non-model species, such as the luna moth (Actias luna) and the Indian meal moth (Plodia interpunctella). To build and augment silk research, we conducted silk experiments with the Indian meal moth. The first experiment compares silk created under different behavioral conditions (wandering silk versus pupal silk). Third-instar larvae were isolated and silk was collected throughout the rest of their lives. The collected silk (wandering and pupal) was slide-mounted and imaged in order to accurately measure widths of individual silk fibers. Our results indicate a difference in strand thickness between wandering and pupal silk. We are building on these results by conducting ongoing experiments to further explore pupal silk. We set up crosses between adults that did and did not produce pupal silk to examine whether the absence of pupal silk is inherited. Additionally, we explored the effect of temperature on the rate of pupal silk production by comparing pupae reared under different thermal conditions.