不同性比对井上蛀果斑螟成虫寿命及生殖力的影响

摘要

井上蛀果斑螟Assara inouei是云南石榴上最为重要的蛀果害虫,为明确不同性比对该虫成虫寿命及生殖力的影响,在温度(25±1)℃、光周期L∥D=15 h∥9h,RH 70％±10％条件下,分别设置1∶4、1∶3、1∶2、1∶1、2∶1、3∶1和4∶1(♀∶♂)共7种雌雄性比处理,研究了性比对井上蛀果斑螟雌雄成虫寿命、产卵前期、产卵期、产卵量和子代卵孵化率等主要生物学参数的影响.结果表明:雌雄性比为2∶1时的产卵期、雌雄成虫寿命均显著长于其余性比,产卵前期短于除3∶1外的其余性比;性比为1∶2时产卵高峰单雌日产卵量显著大于其余性比;性比为1∶3时平均单雌产卵量显著大于其余性比,卵的孵化率显著大于除1∶2外的其余性比.无论在偏雄或偏雌性比条件下,随着雄虫或雌虫比例的增大,产卵前期均先减小后逐渐增大,产卵期均先增大后逐渐减小,平均单雌产卵量均先逐渐增大后减小.偏雄性比条件下子代卵的孵化率高于偏雌条件下.性比对井上蛀果斑螟成虫寿命及生殖力有显著影响,性比偏高或偏低均不利于井上蛀果斑螟种群的生殖.%Assara inouei is the most important pest of pomegranate fruits in Yunnan Province.In order to clarify the effects of different sex ratios on the longevity and fecundity of this pest,the main biological characteristics of the longevity of adult,pre-oviposition duration,oviposition duration,number of eggs laid per female and hatch rate of eggs were systematically examined at seven different sex ratios of female to male at 1 ∶ 4,1 ∶ 3,1 ∶ 2,1-∶ 1,2∶1,3∶1 and4∶1 under the conditions of (25 ± 1)℃,RH 70％ ±10％ and L//D=15 h//9 h.The results showed that the longevity of male and female adults and oviposition duration of A.inouei at the sex ratio of 2∶ 1 were significantly longer than those at other ratios,and the pre-oviposition duration at 2∶1 was significantly shorter than at other ratios except at 3∶ 1.The maximum number of eggs laid per female per day was significantly higher at the sex ratio of 1∶2 than at other ratios.The number of eggs laid per female was significantly higher at the sex ratio of 1∶3 than at other ratios,and the hatch rate of eggs was significantly higher at the sex ratio of 1∶3 than at other ratios except at 1∶2.Under both male-biased and female-biased sex ratios,with the increase of the proportion of males or females,the pre-oviposition period decreased and then gradually increased;the oviposition duration was increased and then gradually decreased,and the number of eggs laid per female increased and then gradually decreased.The hatch rate of eggs under male-biased sex ratios was slightly higher than those under female-biased sex ratios.The longevity and fecundity of adult A.inouei were significantly affected by sex ratio,which significantly decreased when the adult sex ratios were either lower or higher.