Adult XXXX of cold tolerance in a continental-temperate population of @entity238 suzukii.

@entity545 @entity1054 @entity238 @entity1170
UNASSIGNED: @entity238 suzukii (Matsumura) (Diptera: Drosophilidae) is a worldwide emerging pest of soft fruits, but its cold tolerance has not been thoroughly explored. We determined the cold tolerance strategy, low temperature thermal limits, and @entity545 of cold tolerance in both male and female adult D. suzukii. We reared flies under common conditions (long days, 21  C; control) and induced @entity545 by @entity1170 ( @entity1170 , 1h at 0  C followed by 1h recovery), cold acclimation (CA, 5days at 6  C) or acclimation under @entity1054 ( @entity1054 ). D. suzukii had supercooling points (SCPs) between -16 and -23  C, and were chill-susceptible. 80% of control flies were killed after 1h at -7.2  C (males) or -7.5  C (females); CA and @entity1054 improved survival of this temperature in both sexes, but @entity1170 did not. 80% of control flies were killed after 70h (male) or 92h (female) at 0  C, and @entity1054 shifted this to 112h (males) and 165h (females). @entity1054 flies entered chill coma (CTmin) at approximately -1.7  C, which was ca. 0.5  C colder than control flies; @entity1170 and CA increased the CTmin compared to controls. Control and @entity1170 flies exposed to 0  C for 8h took 30-40min to recover movement, but this was reduced to <10min in CA and @entity1054 . Flies placed outside in a field cage in London, Ontario, were all killed by a transient cold snap in December. We conclude that adult phenotypic @entity545 is not sufficient to allow D. suzukii to overwinter in temperate habitats, and suggest that flies could overwinter in association with built structures, or that there may be additional cold tolerance imparted by developmental @entity545 .
