Effect of brief exposures of anesthesia on thermotolerance and metabolic rate of the spotted-wing fly, Drosophila suzukii: differences between sexes?

PUTERO, FLORENCIA A.; MENSCH, JULIAN; SCHILMAN, PABLO E.

JOURNAL OF INSECT PHYSIOLOGY

PERGAMON-ELSEVIER SCIENCE LTD

Año: 2023

0022-1910

The spotted-wing fly, Drosophila suzukii, is a world-wide pest insect for which there is increasing interest in its physiological traits including metabolism and thermotolerance. Most studies focus only on survival to different time exposures to extreme temperatures, mainly in female flies. In addition, it has not been tested yet how anesthesia affects these measurements. We analyzed the effects of anesthesia by brief exposures to cold, anoxia by CO2 or N2 on three standard thermotolerance assays, as well as the aerobic metabolic rate in both sexes. For heat tolerance we measured CTmax by thermolimit respirometry, and CTmin and chill-coma recovery time for cold tolerance. Aerobic metabolism was calculated by CO2 production of individual flies in real time by open flow respirometry. Results showed that females have a significantly higher VCO2 for inactive (at 25°C) and maximum metabolic rate than males. This difference is mainly explained by body mass and disappears after mass correction. Males had a more sensitive MR to temperature than females showed by a significantly higher Q10 (2.19 vs. 1.98, for males and females, respectively). We observed a significantly lower CTmin (X2=4.27, P=0.03) in females (3.68±0.38°C) than males(4.56±0.39°C), although we did not find significant effects of anesthesia. In contrast, anesthesia significantly modifies CTmax for both sexes (F3,62=7.86, P