Effect of short-term high-temperature exposure on the life history parameters of Ophraella communa

Extreme heat in summer is frequent in parts of China, and this likely affects the fitness of the beetle Ophraella communa, a biological control agent of invasive common ragweed. Here, we assessed the life history parameters of O. communa when its different developmental stages were exposed to high temperatures (40, 42 and 44 °C, with 28 °C as a control) for 3 h each day for 3, 5, 5, and 5 days, respectively (by stage). The larval stage was the most sensitive stage, with the lowest survival rate under heat stress. Egg and pupal survival significantly decreased only at 44 °C, and these two stages showed relative heat tolerance, while the adult stage was the most tolerant stage, with the highest survival rates. High temperatures showed positive effects on the female proportion, but there was no stage-specific response. Treated adults showed the highest fecundity under heat stress and a similar adult lifespan to that in the control. High temperatures decreased the F₁ egg hatching rate, but the differences among stages were not significant. Negative carry-over effects of heat stress on subsequent stages and progenies' survival were also observed. Overall, heat effects depend on the temperature and life stage, and the adult stage was the most tolerant stage. Ophraella communa possesses a degree of heat tolerance that allows it to survive on hot days in summer.