Automated survival monitoring system: exploring starvation resistance in newly hatched larvae

Abstract

The mechanisms underlying prolonged survival under starvation condition—after animals have depleted their energy reserves from food—remain poorly understood. For accurate measurement of survival durations, we developed a novel automated survival monitoring system for newly hatched larvae under starvation conditions. This system integrates a CCD flatbed scanner with the automated image analysis software, AutoCircaS. Unlike conventional methods, which are often limited to Drosophila melanogaster Meigen (Diptera: Drosophilidae), our system enables the analysis of the newly hatched larval stage under starvation conditions in other species, such as the black soldier fly, Hermetia illucens L. (Diptera: Stratiomyidae) and the silkworm Bombyx mori L. (Lepidoptera: Bombycidae). Newly hatched larvae of these three species were subjected to starvation conditions, and survival times were recorded in the absence of dietary nutrients. The system achieved an accuracy of 88.5% for D. melanogaster, 79.2% for H. illucens, and 95.0% for B. mori in detecting survival times within 4 h. The median starvation survival times were 1.42 days for D. melanogaster, 6.08 days for H. illucens, and 2.92 days for B. mori, highlighting the particularly long survival of H. illucens compared to the other species. These findings reveal interspecific differences and suggest that variations in ecological backgrounds and adaptive strategies contribute to their starvation tolerance. This system also provides novel insights into the intrinsic starvation responses of insects and offers significant potential for practical applications, such as developing long-term insect preservation techniques through developmental arrest.