Effect of Temperature on the Development and Survival of Scirtothrips dorsalis Strain C（Thysanoptera: Thripidae）

Abstract

: The survival and development of strain C of Scirtothrips dorsalis Hood （ Thysanoptera: Thripidae ） reared on the leaves of Capsicum annuum , were studied at temperatures ranging from − 5 (cid:155) C to 35 (cid:155) C, and the abundance of thrips of strain C living on strawberry （ Fragaria × ananassa Duch. ） plant bodies were investigated under outdoor conditions in Kochi Prefecture, Japan, from October to April 2013–14 and 2014–15. A positive linear relationship was observed between the development rate from egg to adult and temperature in the range of 17.5 (cid:155) C to 32.5 (cid:155) C, allowing the calculation of a lower threshold of 12.4 (cid:155) C for development and a thermal constant of 200.0 degree-days （ DD ） . An exposure time of nearly 3.5 days at 0 (cid:155) C and nearly 2.5 days at − 5 (cid:155) C killed 50% of the adults. In contrast, over half of the 2nd instar larvae survived for more than 5.5 days at 0 (cid:155) C and more than 3 days at − 5 (cid:155) C, while approximately 20% of the larvae exposed to − 5 (cid:155) C for 3 days emerged as adults at 25 (cid:155) C. In the field experiment, both adults and larvae disappeared from the strawberry plants by the end of February 2014 and 2015, with no individuals being found from March onward in either year. These findings suggest that strain C of S. dorsalis is unlikely to survive for the duration of a mild winter under outdoor conditions in Kochi Prefecture, but individuals could survive for a few days, even at temperatures below − 5 (cid:155) C.