The Impact Of Short-term High Temperature On The Asian Corn Borer(Ostrinia Furnacalis)

Asian corn borer(Ostrinia furnacalis) is one of the most important pests of corn in China, severely restrictes corn yields and good quality. As global warming intensifies and farming system and corn varieties changes,the biological characteristics and habits of Asian corn borer phenotype has obviously changed,the damage of Asian corn borer increases frequently and the present detection system as well as pest control system are highly challenged. Temperature is the important ecological factor that influences insect growth and population changes. High temperature causes serious effects on insect physiology and biochemstry, growth and reproduction of survival. At present reseach on heat resistance to insects are widely reported, however research on toletance of high temperayure in Asian corn borer is limited.This study uses heat shock recovery test to explore the heat resistance of Asian corn borer’s egg, larva, pupa and adult,providing scientific basis for the prediction of Asian corn borer; and investigated the changes of trehalose content of Asian corn borer 5th instars larvae under different high temperatures, useing real-time quantification PCR technology to test the expression of heat shock protein Hsp90 in relation to temperature changes, fuether discuss the adaptation mechanism of the Asian corn borer to high temperature stresses. The following results are obtained from this study:1. Asian corn borer’s hatching rate, pupation rate, eclosion rate and survival rate are all gradually reduced with the heat shock temperature increases. Results also showed that in Asian corn borer four life states, the 5th instars larvae and pupae are more thermotolerant than eggs and adults, and the heat resistance in female adult is significantly higher than that in male.2.5th instars larvae’s trehalose content increased at first and then decreased with the rise of temperature. The trehalose content in female body peaked at 11.4 mg/g at 38℃, then as the temperature levels decreases, and in the male body at 42℃ trehalose content peaked at 14.8 mg/g, at 44 ℃ levels drop but is still higher than normal. Under high temperature stress the trehalose content of Asian corn borer male 5th instars larvae have broader dynamic range than that in female, and female’s trehalose peaked content is lower than that in male at induced temperature.3. Asian corn borer male and female 5th instars larvae’s Hsp90 expression all increased at first and then decreased with the rise of temperature, and expression level reached the maximum at 42℃; At 27℃、 40℃、 42 ℃、 44℃, the expression of Hsp90 in male larvae is significantly higher than that in female.4. The induced temperature of trehalose peak value is higher and the heat shock resilience of Asian corn borer 5th instars larvae is stronger. The heat resistance performance of trehalose and heat shock protein Hsp90 in Asian corn borer 5th instars larvae only work within certain limits of temperature. Beyond the temperature range, the Asian corn borer’s resistance mechanism will lose protection.