Climate stress resistance in male Queensland fruit fly varies among populations of diverse geographic origins and changes during domestication

Abstract

Background The highly polyphagous Queensland fruit fly (Bactrocera tryoni Froggatt) expanded its range substantially during the twentieth century and is now the most economically important insect pest of Australian horticulture, prompting intensive efforts to develop a Sterile Insect Technique (SIT) control program. Using a “common garden” approach, we have screened for natural genetic variation in key environmental fitness traits among populations from across the geographic range of this species and monitored changes in those traits induced during domestication. Results Significant variation was detected between the populations for heat, desiccation and starvation resistance and wing length (as a measure of body size). Desiccation resistance was correlated with both starvation resistance and wing length. Bioassay data for three resampled populations indicate that much of the variation in desiccation resistance reflects persistent, inherited differences among the populations. No latitudinal cline was detected for any of the traits and only weak correlations were found with climatic variables for heat resistance and wing length. All three stress resistance phenotypes and wing length changed significantly in certain populations with ongoing domestication but there was also a strong population by domestication interaction effect for each trait. Conclusions Ecotypic variation in heat, starvation and desiccation resistance was detected in Australian Qfly populations, and these stress resistances diminished rapidly during domestication. Our results indicate a need to select source populations for SIT strains which have relatively high climatic stress resistance and to minimise loss of that resistance during domestication.

Chill coma recovery of Ceratitis capitata adults across the Northern Hemisphere

“…Drosophila species overwinter as adults and faster recovery from a cold stress provides fitness benefits during the cold season by increasing overwinter survival 18 . On the other hand, latitudinal trends of chill coma recovery time were absent across Australian populations of Bactrocera tryoni 36 and Bombus vosnesenskii workers from Western United States 39 . In this study, C. capitata adults that reside in the Mediterranean Basin (35-40°) exhibited faster recovery than those from southern and northernmost populations, indicating a curvilinear relationship between chill coma recovery time and latitude across the Northern Hemisphere.…”

Raspberry ketone feeding makes Queensland fruit fly, Bactrocera tryoni (Froggatt), more vulnerable to desiccation but not starvation

“…Raspberry ketone (RK) feeding as pre‐release supplement has been found to accelerate sexual maturation in immature Qflies, with RK‐fed males mating much earlier without any negative impact on survival in the absence of stress 27 . Previous study showed that resistance to desiccation and starvation stress changes in Qfly males due to domestication 56 . Thus, it is important to know whether stress resistance is affected by RK supplementation in Qfly so that decisions could be made about when and where RK might safely be used as a pre‐release supplement in SIT operations.…”

“…27 Previous study showed that resistance to desiccation and starvation stress changes in Qfly males due to domestication. 56 Thus, it is important to know whether stress resistance is affected by RK supplementation in Qfly so that decisions could be made about when and where RK might safely be used as a pre-release supplement in SIT operations.…”

Transmission mode predicts coinfection patterns of insect‐specific viruses in field populations of the Queensland fruit fly

“…Here, we investigated the diversity, distribution, prevalence, coinfections and viral loads of ISVs in field populations of the Queensland fruit fly (Qfly; Bactrocera tryoni ) throughout its distribution. This tephritid species is Australia's most significant horticultural pest, has a wide climatic and geographic range (Popa‐Báez, Lee, et al., 2020), can infest fruit of over 40 plant families and is a key biosecurity threat (Hancock et al., 2000; Plant Health Australia, 2018; White & Elson‐Harris, 1992). It originated from the tropical and subtropical rainforests of Queensland (QLD) and northern New South Wales (NSW) and has spread across many other (including temperate) regions due to the planting of host plants and trade of produce from the mid‐19th century onwards (Dominiak & Daniels, 2012).…”