The effect of captive breeding upon adult thermal preference in the Queensland Fruit Fly (Bactrocera tryoni)

Publication date: Available online 18 October 2018Source: Journal of Thermal BiologyAuthor(s): Kate E. Lynch, Thomas E. White, Darrell J. KempAbstractThe Queensland fruit fly (Bactrocera tryoni) is a generalist pest that poses a significant threat to the Australian horticultural industry. This species has become broadly established across latitudes that encompass tropical to temperate climates, and hence populations occupy diverse thermal niches. Successful expansion across this range may have been brokered by evolutionarily labile features of breeding phenology, physiology and/or behaviour. We explored the potential role of behavioural flexibility by characterizing variation in adult thermal preference using a novel gradient apparatus. Flies oriented within this apparatus essentially at random in the absence of thermal variation, but sought and maintained precise positions when presented with an established gradient. Male and female flies from an ‘old’ colony (>300 generations) and a ‘young’ (F7) colony were compared. Whereas we found no difference between the sexes, flies from the young colony preferred higher temperatures (30.93 ± 7.30 oC) and had greater individual variation than their counterparts from the old colony (28.16 ± 5.63 oC). Given that B. tryoni are routinely maintained at 25 oC in the laboratory, a lower mean preference of the old colony is consistent with thermal adaptation. This is further supported by their reduced phenotypic variance, ...
Source: Journal of Thermal Biology - Category: Biology Source Type: research