Effects Of High Temperature On Development And Fecundity Of Ostrinia Furnacalis(Guenée)

Ostrinia furnacalis(Guenée)is the most important pest in maize production in China.Its serious harm has become a major factor restricting high yield and grain safety of maize,which is a major problem regarding maize production currently.For a long time,a great deal of research has been made on the external causes of the damage and the development of technologies that rely on external disturbances to control their hazards.However,with the increase of global warming in recent years,the phenotype of biological characteristics and hazard habit of Asian corn borer has changed obviously,the damage has been increasing,the frequency of occurrence is increasing,and the existing early warning,prevention and control systems are facing severe challenges.Thus,It is important to study the biological response of Asian corn borer to high temperature under the condition of climate warming.It is of great significance to develop the corresponding control strategies and control techniques for different ecological zones and different generation areas.In this paper,the effects of extreme high temperature on the egg period of Asian corn borer,effects of extreme high temperature on growth and development of Asian corn borers at different ages and the effect of single high temperature on the reproduction performance of adult Asian corn borer were studied.Through these studies,the differences in heat tolerance and the effects on the growth and development of Asian corn borers at different developmental stages were clarified.The main results of the study are as follows:1.The effects of short-term extreme temperature on the egg period of Asian corn borer were studied.The pupation rate and pupal weight of Asian corn borer larvae decreased significantly at the high temperature of 42? during 1-3 hours.The high temperature effect of the egg may be transmitted to the adult by the influence of the pupal weight,and the life span of the adult is decreasing.The increase in the temperature of the subsequent recovery will help to accelerate the survival and development of larvae after the high temperature of eggs,which means a higher recovery temperature can remedy the adverse effects of high temperature long time treatment on Asian corn borers.2.The differences in heat tolerance between short-term and high-temperature of Asian corn borer larvae at different ages were studied.With the increase of exposure time of 42?,the survival rate of Asian corn borers at different ages was significantly decreased.And the heat tolerance of Asian corn borers at different ages was significantly different--the heat resistance order from the highest to the lowest is L3>L2>L1.The test also found that the heat resistance of the female was significantly higher than that of the male.3.The effects of extreme high temperature on the reproduction performance of adult Asian corn borer were studied.The high temperature of 2-3h did not cause the immediate death of adult Asian corn borer,but the prolongation of heat treatment time could lead to the significant decrease of lifespan,egg production and egg hatching rate.Moreover,the adverse effects of high temperature treatment do more harms to the female than the male.