Exigências térmicas de estágios imaturos de Galleria mellonella L. (Lepidoptera: Pyralidae)

Abstract

The rearing of Galleria mellonella L. in laboratory is important for multiplication of entomopathogenic nematodes, mandatory for biological control studies. The objective of this study was to evaluate the effect of three thermal profiles on development stages of this insect, allowing synchronization of cycle production. Two distinct rearing phases were done: firstly, using nucleous of incubation for development of eggs and, secondly, using circular-aluminum manifolds for development of larvae and pupae. The time necessary for development of the immature stages decreased with higher temperatures. Incubation periods lasted 13.4 days at 22°C, 8.3 at 27°C and 6.8 days at 32°C, while periods for larvae development lasted 40.4, 27.2, and 23.4 days, respectively, for the same temperatures. Development to pupal stage was observed 18.2, 15.0, and 12.2 days, respectively, for the same temperatures. Larval survival was higher at 32°C, however embryonic stages and pupae survival were higher at 27°C. and 22°C, respectively. The threshold temperature was 11.209167°C for the embryonic development stage, 7.695869°C for larval stage, and 1.943050°C for pupal stage of G. mellonella. Thermal constants were 138.380533 DG (degree day) for egg, 554.968830 DG for larvae, and 369.054080 DG for pupae.