The Indian meal moth (Plodia interpunctella) is becoming an important biological model to study silk. While there are many potential applications to materials science and medicine, many aspects of silk production in this species remain unknown. Here we characterize the silk of P. interpunctella by measuring the width of larval wandering and pupal silk strands and find that the latter is significantly thicker than the former. We also report intraspecific variation in pupal silk production in our lab-reared colony with a very small number of individuals forgoing pupal silk production entirely (< 4%). Overcrowding had no effect on silk formation, but exposure to elevated temperature reduced pupal silk production.