高温胁迫对异迟眼蕈蚊与韭菜迟眼蕈蚊的致死作用及后续发育繁殖的影响

Lethal effects of heat stress on Bradysia difformis and Bradysia odoriphaga and its subsequent effects on development and fecundity

异迟眼蕈蚊Bradysia difformis Frey与韭菜迟眼蕈蚊Bradysia odoriphaga Yang et Zhang是食用菌的两种重要的害虫,对食用菌的质量及产量危害极大。高温处理是食用菌生产过程中常用的措施,但其对眼蕈蚊害虫的防治效果研究尚未有报道。【目的】为明确高温胁迫对两种眼蕈蚊存活及繁殖的影响,探究高温防治的可行性。【方法】本文探究了高温胁迫(30~40℃)对两种眼蕈蚊各虫态存活的影响,并进一步分析短时高温胁迫对存活幼虫和成虫后续发育和繁殖的影响。【结果】当温度超过36℃对各虫态产生明显的短时致死效应。4种虫态中,成虫耐热性最差,蛹的耐热性最强。38℃下,异迟眼蕈蚊与韭菜迟眼蕈蚊成虫致死中时间LT50分别为0.493~0.553 h和1.335~1.431 h;蛹LT50分别为1.402 h和2.356 h。经短时间高温胁迫后,存活幼虫后续化蛹明显推迟,成虫产卵量下降,38℃处理2 h,存活异迟眼蕈蚊与韭菜迟眼蕈蚊幼虫化蛹时间分别推迟3.09 d和1.93 d,产卵量较对照分别下降了74%和60%。经高温胁迫后,存活成虫后续的寿命缩短,繁殖力下降。38℃处理1 h,存活异迟眼蕈蚊与韭菜迟眼蕈蚊雌成虫寿命分别缩短了1.60 d和1.57 d,产卵量较对照分别下降了59%和40%。【结论】高温胁迫(≥36℃)会影响两种眼蕈蚊各虫态存活,并对存活个体后续发育繁殖有明显的抑制作用。因此,高温处理可作为食用菌生产过程中防治眼蕈蚊的物理措施。

Bradysia difformis Fey and Bradysia odoriphaga Yang et Zhang are important pests of edible mushrooms that cause significant economic losses to mushroom growers. Heat treatment is a common measure to prevent crop damage caused by these pests and other pathogens during the production of edible fungi. However, it remains unclear whether heat treatment is effective in controlling B. difformis and B. odoriphaga in mushroom houses. [Objectives] To determine the effects of high temperature on the survival and fecundity of B. difformis and B. odoriphaga, and determine the practicality of using heat treatment to control these pests. [Methods] We tested the effects of long- and short-term heat stress on the survival of B. difformis and B. odoriphaga, and on the development, longevity and fecundity of larvae and adults of both species. [Results] Temperatures above 36℃ had rapid lethal effects on the survival of both B. difformis and B. odoriphaga. Of the four life-stages examined, pupae were the most tolerant to heat stress and adults were the most sensitive. At 38℃, the LT50 （the median lethal time） of B. difformis and B. odoriphaga adults were 0.493-0.553 h and 1.335-1.431 h respectively, while the corresponding values for pupae were 1.402 h and 2.356 h, respectively. Short-term heat shock adversely affected the development and fecundity of surviving larvae. Exposure to 38℃ for 2 h delayed the development of surviving B. difformis and B. odoriphaga larvae by 1.93 d and 3.09 d, respectively, and reduced fecundity by 74% and 60%, respectively compared to the respective 25℃ control groups. Exposure to 38℃ for 1 h reduced the longevity of surviving B. difformis and B. odoriphaga adults by 1.60 d and 1.57 d, respectively, and fecundity by 59% and 40%, respectively compared to the respective 25℃ control groups. [Conclusion] Short-term heat shock （≥ 36℃） had lethal effects on B. difformis and B. odoriphaga and also significantly inhibited the development and fecundity of surviving larva and adults. These results indicate that heat treatment can be used to control B. difformis and B. odoriphaga in mushroom houses.