Impact of temperature hardening on thermal tolerance and reproduction in Frankliniella occidentalis

Key Words： Frankliniella occidentalis, temperature hardening, reproduction

Abstract：The western flower thrip, Frankliniella occidentalis （Pergande）, is an important insect pest of vegetables and ornamentals.Populations of this pest display marked seasonal fluctuations in which temperature is considered the most important factor.In order to explore the effect of temperature on F.occidentalis, threeday adults were exposed to 18 or 31℃ for 1, 2 and 3 d, after which their temperature tolerance and reproduction was investigated.The results suggest that continual exposure to 18℃ markedly improved cold and heat tolerance.Cross tolerance in response to cold and heat stress was observed.However, although exposure to 32℃ obviously increased adult heat tolerance, cold tolerance was not improved accordingly.Reproduction obviously declined after exposure to 18℃ but was unaffected by exposure to 31℃.Our results confirm that temperature tolerance is achieved at the cost of decreased reproduction.