| As_invasive nature enemy of A.philoxeroides, flea beetle (Agasicles hygrophila) had achieved good control effect. However, due to seasonal changes and the impact of the temperature difference between north and south, flea beetle breeding populations was restricted. Studies had shown that the ecological adaptability of A.philoxeroides was greatly influenced by the temperature, comprehensive performance as insects respond to temperature changed in behavior, by exploring the behavior changes in unsuitable temperature, can reveal the external performance of flea beetle unsuitable temperature tolerance. In this paper, under unsuitable temperature zone, researching the knockdown behavior before and after acclimation Tk, movement time ratio Rm, jumping times Nj, crawling height He and so on, The main results were as follows:High-temperature test showed that knock-down behavior occured in 38℃45℃, and instantly recovery after knockdown. Its "temperature-knock-down time" curve relationship was:Tk♀=4E+59x-35.31, Tk♂=3E+55x-32.94. After high temperature acclimation in 37.5℃ and 4h, the knock-down time increased, heat resistance improved. The relationship between male and female curves, respectively: Tk♀A=5E+56x-33.39, Tk♂A=8E+56x-33.58. No matter before or after acclimation, the heat resistance of females was more than males, we found that exercise time proportion of flea beetle increased with temperature, and the male more active than the female; the number of jumps exhibit wave curve; At 40℃ and 41℃, the behavior of the male was more active than the female; when the temperature was 44℃ and 45℃,activity of the female was larger than the male; after high temperature acclimation, at 38℃45℃, the activity and heat resistance of males and females improved significantly.Low-temperature test showed that flea beetle knock behavior occurred at all set temperature gradients, and the knock-down times decreased with decreasing temperature. Its "emperature-time down long" curve relationship:Tk♀A=12.685e0.2835x, Tk♂A=9.4117e0.2624x. After cold acclimation in 5℃ and 4h, the cold resistance of flea beetle significantly improved at 10～12.5℃, and the curve was:Tk♀A=10.233e0.3475x, Tk♂A=10.404e0.3211x. No matter before or after acclimation, the cold resistance of females was more than males. During low temperature knock-down behavior reaction process had two turning points:2.5℃ and 7.5℃. Specific performance as:above 7.5℃, after knock-down, the male and female insects can self-recovery; Below 7.5℃, chilling unconscious phenomenon occured, and need to lift at room temperature; Under 7.5℃, it was happened two kinds of behavior; At 2.5℃, the knock-down behavior happened twice, and it didn’t happen in other temperature treatments. At 12.5-7.5℃, after knocking-down, flea beetle can walk normally after a period time, its long recovery curve changes was Tkr♀=1.6339x2-39.272x+242.17, Tkr♂=-0.2025x+12.677, Tkr2A=2694.3e-0.506x, Tkr♂A=5447.3e-0.544x; At-2.5～7.5℃, the process of flea beetle behavior changed:knock-down at low temperatures-into a coma-coma continued at room temperature-resuming; at room temperature recovery curve was: Tccr♀=103.46e-0.138x, Tccr♂=-1.0033x2-3.8862x+121.34, Tccr♀A=86.653e-0.048x, Tecr♂A=4.4873x+88.538. Activities of male and female flea beetle as follows:activities ruduced with decreasing temperature at 12.5～7.5℃, weak activity; at 5-2.5℃, activities increased with decreasing temperature, at 0～-2.5℃,the trend of activities was stable.After knocking-down at 45℃, survival rate of the male and female insects, fecundity, hatching rate of flea beetle decreased significantly, it showed that extreme high temperature season has a larger effect on population. Knocking down at 2.5～10℃, the fecundity and hatching rate was significantly lower than the control group. According to range of flea beetle reproduction, low temperature can give them greater damage than high temperature, indicating that the population diffusing and migrating to the north was difficult.By studying behavioral regularities and effect of acclimation in high and low temperature, we founded that the knock-behavior occured at 38～45℃,-2.5～12.5℃ and high temperature was more sensitive than low temperature. The heat tolerance of 38～45℃ and the cold resistance of 10～12.5℃ were significantly increased. Comprehensive high and low temperature, and the acclimation research results showed that female heat resistance and cold resistance were higher than that of male, and acclimation can increased the temperature tolerance. In this paper, we discussed the behavioral strategies of flea beetle, combined with heat shock protein, protection enzyme system, the influence of extreme temperature etc. several aspects discussed flea beetle temperature zone and adaptability. |
PDF Full Text Request