摘要：
Apolygus lucorum (Meyer-Dür) and Adelphocoris suturalis Jakovlev (Hemiptera:Miridae) are the major pests of cotton because of the widespread adoption of Bt transgenic cotton in China and an associated reduction in pesticide use.The effects of short-term heat stress on the survival and fecundity of the two plant bugs were studied to understand changes in the biological characteristics of plant bugs encountering high temperature stress.The egg hatch rate,nymph survival rate,and reproduction of A.lucorum and A.suturalis in incubators were evaluated after the eggs and nymphs were exposed to 27,30,33,36,or 40°C for 4 h each day.Within the range of 27 to 40°C,the egg hatch rate of A.lucorum increased from 84.25％ at 27°C to 94.69％ at 30°C,then decreased to 44.30％ at 40°C;whereas the egg hatch rate of A.suturalis increased from 79.27％ at 27°C to 87.90％ at 30°C,then decreased to 60.24％ at 40°C.After exposure to 40°C for 4 h,the egg hatch rate of A.suturalis was higher than that of A.lucorum;this indicated that the heat tolerance of A.suturalis eggs was significantly higher than that of A.lucorum.The nymph survival rates of both species decreased with an increase in temperature.Within the range of 30 to 40°C,the nymph survival rate of A.lucorum decreased from 70.47％ to 0％,whereas that of A.suturalis varied from 69.65％ to 16.74％.Furthermore,female reproduction of both species was affected by high temperature.The mean egg number of A.lucorum adult females increased from 64.78 at 27°C to 70.03 at 30°C,then decreased slowly.A.lucorum did not lay eggs at 40°C.There was not a significant difference among the mean numbers of eggs laid by A.suturalis females from 27°C to 36°C.However,exposure to 40°C for 4 h each day resulted in a mean egg number of 20.75 for A.suturalis.In addition,duration of the nymphal stadia of A.lucorum was extended from 11.01 days at 27°C to 13.67 days at 36°C exposure.For A.suturalis,the duration of the nymphal stadia was extended from 13.05 days at 27°C to 16.58 days at 40°C exposure.The longevity of both sexes of A.lucorum adults decreased 2 to 4 days with exposure to 27°C and 36°C,respectively,whereas the longevity of both sexes of A.suturalis adults decreased 11 to 13 days with exposure to 27°C and 40°C,respectively.In conclusion,the egg hatch rate,survival rate,and reproduction of A.lucorum and A.suturalis significantly decreased after exposure to higher temperatures.However,A.suturalis was more adapted to 40°C than A.lucorum when both survival and fecundity were considered.The adaptive divergence of tolerance to extreme high temperature may be an important factor differentiating seasonal dynamics and distribution of these species in cotton fields.%绿盲蝽和中黑盲蝽是危害棉花害虫的两个优势种,为探明短时高温暴露对绿盲蝽和中黑盲蝽存活和生殖的影响,将在27°C饲养的绿盲蝽和中黑盲蝽的卵和初孵若虫每天暴露在不同高温(30、33、36、40°C)4 h,以27°C恒温饲养的为对照,比较两种盲蝽卵的孵化率、若虫存活率、成虫产卵量的变化以及两者的差异.研究结果显示:在27-40°C范围内,随着温度的升高,绿盲蝽卵的孵化率先从27°C处理的84.25％上升至30°C处理的94.69％,而后开始下降,36°C处理的孵化率下降为76.84％,到40°C处理时降至44.30％;中黑盲蝽卵的孵化率则由27°C处理的79.27％上升至30°C处理的87.90％,后逐渐下降至40°C处理的60.24％.在极端高温40°C的处理中,中黑盲蝽卵的孵化率显著高于绿盲蝽卵的孵化率,表明中黑盲蝽卵较绿盲蝽卵更耐极端高温.在30-40°C范围内,随着温度的升高,两种盲蝽若虫存活率降低,40°C处理后,绿盲蝽若虫存活率为零,中黑盲蝽若虫存活率为16.74％.同时,高温对绿盲蝽和中黑盲蝽的产卵量也存在显著影响.27°C处理下,绿盲蝽平均每头雌虫产卵量为64.78粒;30°C处理后,产卵量上升为70.03粒,后随处理温度升高产卵量开始下降,40°C时不能产卵;中黑盲蝽产卵量在27-36°C之间没有显着差异,平均每头雌虫产卵量为63-75粒,显著高于40°C处理的20.75粒.此外,短时高温暴露延长了绿盲蝽和中黑盲蝽的若虫历期,降低了绿盲蝽和中黑盲蝽雌雄成虫寿命.结果表明,短时高温对绿盲蝽和中黑盲蝽卵的孵化率、若虫存活率、生殖及成虫寿命等均有不利影响,温度越高,影响越大.绿盲蝽和中黑盲蝽在极端高温40°C处理下,中黑盲蝽耐热性明显高于绿盲蝽.两种盲蝽在极端高温条件下的耐热性不同,可能是导致它们在棉田内种群季节动态差异的一个重要因素.
