Effects of heat hardening on life parameters and thermostability of Bradysia odoriphaga larva and adults

High temperature in summer is a key barrier for Bradysia odoriphaga (Diptera: Sciaridae), a serious pest of vegetables in China. Because mild heat hardening can enhance the thermotolerance of many insects, we determined if heat hardening was beneficial for B. odoriphaga adaptation to high summer temperatures. We studied the biological performance, antioxidant responses and hsp70 and hsp90 expression of B. odoriphaga 4th instar larvae and adults after pre-exposure to mild heat hardening temperatures (30-36°C). The tolerance of larvae to severe heat stress was enhanced after mild heat hardening (32-36°C). However, life parameters were significantly inhibited, development was delayed, longevity was shortened and fecundity was decreased. Mild heat hardening (30-34°C) caused serious adverse effects on life parameters and less enhancement of heat resistance for 4th larvae. Mild heat hardening at 36°C weakened the heat tolerance of adults. The activity of four antioxidant enzymes in B. odoriph...

夏季高温是韭菜迟眼蕈蚊（Bradysia odoriphaga，双翅目：眼蕈蚊科）的关键生存限制因子，该虫是中国蔬菜生产中的重大害虫。由于温和热驯化（mild heat hardening）可增强多种昆虫的耐热性，本研究旨在探究温和热驯化是否有助于韭菜迟眼蕈蚊适应夏季高温。我们针对预暴露于温和热驯化温度（30~36℃）后的韭菜迟眼蕈蚊4龄幼虫与成虫，分析了其生物学表现、抗氧化应答以及hsp70与hsp90的表达水平。经32~36℃温和热驯化后，幼虫对极端热胁迫的耐受性显著提升。但与此同时，其生命参数受到显著抑制：发育进程延迟、寿命缩短、繁殖力下降。30~34℃的温和热驯化对4龄幼虫的生命参数造成严重不利影响，且对其耐热性的提升效果较弱。而36℃的温和热驯化则会削弱成虫的耐热性。韭菜迟眼蕈体内四种抗氧化酶的活性……