Fat loss tips from flesh flies: a biochemical analysis of resource use during diapause

Diapause is a critical life-history strategy that allows insects to escape poor environmental conditions. Diapause has been reported in every developmental stage in insects, however, most species diapause within one specific stage. During diapause, the judicious use of resources is critical, especially in species that diapause in non-feeding stages, such as pupae. Pupal-diapausing species must not only maintain enough stores to initiate and survive for months without food or water, but they must also be able to complete development and have enough reserves remaining to locate food as an adult. We evaluate resource use during pupal-diapause in the flesh fly, Sarcophaga crassipalpis. While many species rely on energy-dense triacylglycerides as fuel during diapause, previous research has suggested that S. crassipalpis may switch to another fuel source during diapause. To better characterize resource use during diapause we used a combination of biochemical and metabolic tools to carefully dissect nutritional changes during diapause. Contrary to previous work, we found that S. crassipalpis largely relies on lipid to fuel diapause and to complete development.