| In natural environments, insects experience periodic repeated high temperatures on several daystimescale. Climate warming is predicted to increase the intensity, duration and frequency of extremeheat-waves and hot days.It implicates that the studies of impacts of periodic repeated heats on insects atseveral days timescale have been more realistic. Significant impacts of periodic high temperatures on ifehistories, physiological and biochemical characteristics of insects have been showed.However,there aresome questions in these researches;such as temperature designs, research characteristics and species ofinsects.Our studies take environment temperatures fully into account, simulating high temperaturevariations on several days timescale.We study the effects of mid-timescale periodic high temperatureson life history traits of Sitobion avenae.The main results were displayed as follows:1Increasing successive hot days of mid-timescale periodic hot days have significant impacts onaphids’ life history. Developmental times of immature aphids are notffected by increasing hot days;survival rates of immature aphids are slightly affected by increasing hot days. Longevities,reproductions of aphids are decreasing under increasing hot days.2Increasing hot days’ frequencies of mid-timescale periodic hot days have significant impacts onaphids’ life history. Developmental times of immature aphids are different under different temperaturepatterns; survival rates of immature aphids are slightly affected by increasing hot days’ frequencies.Longevities, reproductions of aphids are decreasing under increasing hot days’ frequencies.3Same periodic days, increasing hot days and decreasing normal days have significant impacts onaphids’ life history. Periodicity is not an influence factor on aphids’ life history. The main influencefactors on aphids’ life history are successive hot days and hot days’ frequencies.4Same ratio of hot days and normal days with different periodic hot days has same impacts onaphids’ life history, and more researches are needed.In these patterns, adult aphids are more influnced by changes of hot days than immature aphids.Aphids’ development stages of hot days occurring are influnce facters which can impact developmentaltimes and survival rates of immature aphids. While hot days which occurring at different life stages ofaphids do not effect on changing trends of aphids’ life history, different life stages influnce the effectdegrees of these characteristics. |
