Abstract: 【Aim】 Monochamus alternatus is an important wood-boring pest of pine forests in southern China, and also the main vector insect of Bursaphelenchus xylophilus. Investigating the effects of heat wave events on the reproductive properties of M. alternatus can provide a theoretical basis for the prediction of its population dynamics and the epidemiological pattern of B. xylophilus under the context of global warming. 【Methods】The 16-day-old adults of M. alternatus were subjected to a simulated heat wave treatment (40 ℃ for 72 h), subsequently placed at the room temperature (25 ℃) and allowed to mate and oviposit. The variation rules of the reproductive parameters, such as daily average number of eggs laid per female, egg length, egg duration and hatching rate, and the body weight of offspring larvae were observed every week as an observation period. 【Results】 There was no significant difference in the daily average number of eggs laid per female between the heat wave treatment group and the control group. Egg length in the heat wave treatment group was 0.09 mm shorter than that in the control group in the 1st observation period, and then exceeded and remained longer than that in the control group after the 2nd observation period. The egg duration in the heat wave treatment group was 1.16 d longer than that in the control group in the 1st observation period, and then was the same as that in the control group in the 2nd observation period and shorter than that in the control group thereafter. The hatching rate of eggs in the heat wave treatment group decreased from 91.83% to 63.04% until the 4th observation period when it recovered to the same level as that in the control group. In terms of the body weight of offspring larvae, the heat wave treatment group and the control group reached the same level after 28 d of rearing, regardless of the variation in the body weight of the newly hatched larvae. 【Conclusion】 The heat wave event simulated in the laboratory has a negative impact on the reproductive parameters of M. alternatus in the short period. However, after relieving of heat wave stress, the reproductive ability of adult M. alternatus can be restored in a relatively short period of time, usually returning to normal levels after 7 d, and is even promoted to a certain extent, demonstrating its poisonous euphoria response to the heat wave stress. These results indicate that M. alternatus can still maintain a high population density in its original distribution area under the climate warming conditions.

Key words: Monochamus alternatus, climate warming, heat wave, fecundity, offspring fitness