Synergistic effects of developmental temperature and rearing diet on the thermal tolerance and performance of a cactophilic Drosophila.

KREIMAN LUCAS; EDUARDO SOTO; DANIELA PELUSO; ESTEBAN HASSON; PABLO SCHILMAN; JULIÁN MENSCH

Rennes

Congreso; 9 International Symposium of Environmental Physiology of Ectotherms and Plants; 2022

The developmental temperature has a profound effect on the fitness of ectotherms. Also, diet composition has been shown to affect a range of relevant characters in these organisms. However, the combined effects of these factors have been rarely tested. The present study will focus on the combining effect of developmental temperature and rearing diet on the thermal tolerance and performance of the cactophilic species Drosophila buzzatii. Specifically, we measure chill coma recovery time, as well as the fitness components of juvenile survival, developmental rate and ovariole number at six developmental temperatures to construct thermal performance curves for each diet. Using these data, we tested the synergy of these factors on the plasticity of thermal performance and tolerance. Remarkably, we found that only when flies were reared on a semi-natural diet and under a daily temperature fluctuation (DTF) (4-16°C; mean = 10°C) cactophilic flies can complete development in about 90 days (duration of winter) and attained a high cold tolerance. Conversely, if flies were reared under constant temperature (10°C) or on a standard diet (with or without variable temperatures) they failed to complete their development. So, only when more than one natural treatment was included, i.e., semi-natural diet and DTF, we found that flies can overwinter as larvae and pupae. The natural diet of necrotic cactus consumed by cactophilic Drosophila combined with winter thermal variability allows overwintering survival and enhanced cold tolerance.