An ecological study of the Indian-meal moth Plodia interpunctella (Hübner) with emphasis on diapause

Abstract

"The Indian-meal moth, Plodia interpunctella (Hubner), is an important pest of stored food products, especially dired fruits and nuts in California, and many other parts of the world. Many authors believe that this species will grow and breed continuously under favorable conditions. Some experimental data obtained in California, however, suggested that late in the season the insect may enter a facultative diapause as a mature larva. The present investigation has shown that this actually occurs. The investigation indicated that throughout much of California diapause occurs in the fall, probably because temperature during incubation of the eggs is sufficiently high to induce diapause and later, during larval growth, sufficiently low to allow diapause to occur. Temperature acclimatization increased the cold-hardiness of both diapausing and nondiapausing individuals. However, diapausing larvae were more cold-hardy than nondiapausing larvae of the same strain. Two strains of Plodia interpunctella were investigated in this study and it was found that they exhibited a marked difference in tendency to diapause."