大麦虫作为替代寄主和人工饲料繁育花绒寄甲对其繁殖生物学的影响

The Effects of Zophobas atratus(Coleoptera:Tenebrionidae)as a Substitute Host and an Artificial Diet on Mass Rearing of the Wood-borer Parasitoid Dastarcus helophoroides(Coleoptera:Bothrideridae)

花绒寄甲Dastarcus helophoroides是防治多种蛀干害虫天牛的重要天敌,为了解决人工大量繁育花绒寄甲的技术问题,本文选用大麦虫Zophobas atratus蛹作为繁育花绒寄甲幼虫的替代寄主,利用配置的人工饲料饲喂成虫,在实验室中连续饲养4代花绒寄甲,统计分析所繁育出的每代花绒寄甲成虫的产卵量、产卵前期时长、雌雄性比、成虫体长和体宽、体质量、卵的孵化率以及其后代幼虫的寄生率等,分析人工饲料和替代寄主对室内连续多代繁育的花绒寄甲繁殖生物学的影响。结果表明:花绒寄甲成虫的体长、体宽、体质量随着室内饲养代数的增加而减小;花绒寄甲成虫的产卵前期随着饲养代数的增加而延长,但后一种情况通过在饲料中添加维生素可有效解决。随着室内饲养花绒寄甲代数的增加和人工繁育时间的延长,平均每头花绒寄甲雌虫的产卵量增加;使用替代寄主繁殖4代后出现成虫雌雄性比下降,不符合1:1的情况。室内饲养4代的花绒寄甲卵的孵化率和初孵幼虫的寄生率几乎没有影响。通过对各个繁殖生物学指标的比较发现,饲喂改良人工饲料的花绒寄甲成虫的产卵前期在饲养多代后能明显缩短;利用大麦虫蛹繁育出的花绒寄甲后代雄虫数量明显多于雌虫;相反,利用改良人工饲料与花绒寄甲原始寄主松褐天牛幼虫配合使用,繁育出的第2、3代雌虫数量明显多于雄虫,差异显著。综上所述,利用大麦虫作为替代寄主会导致花绒寄甲后代雌雄性比下降,但可以通过改进饲料配方和利用原寄主饲养,在室内饲养多代后对花绒寄甲繁殖生物学的各项指标影响不大。因此,利用大麦虫和人工饲料等饲养技术综合应用,能够在室内人工规模化繁育花绒寄甲。

A wood borer parasitoid,Dastarcus helophoroides is an effective natural enemy as biocontrol agent for those pests in China.However,it has been difficult for mass rearing the parasitoid for biocontrol applying.In order to solve the problem,we carried out a study on the technique of mass rearing the parasitoid.We chose Zophobas atratus(Fabricius)as a substitute host for rearing its larvae,and use the artificial diets in its adult stage.We reared D.helophoroides for four generations in laboratory continuously,and analyze the spawning amount,the preoviposition period,the sex ratio,the body length,the body width,the body weight,the hatching rate of the eggs and the parasitism rate.The effect of artificial feed and substitute hosts on the multiple generations of rearing in the house was analyzed.The results showed that,the body length,body width,body weight of the parasitoid adults decreased with the increase of the indoor rearing generations;the adults preoviposition period was prolonged with the increase of the rearing generations,which could be effectively restrained by adding vitamins in the artificial diet;with the increasing of the number of generations and the extension of the time,the average number of eggs layed by per female increased;the ratio of male to female was not consistent with 1:1 after four generations of reproduction with substitute hosts;the hatching rate of the eggs and the indoor parasitism rate of the newly hatched larvae were almost not affected by the four generations of indoor mass rearing.Compared various reproductive biological characteristics indexes of different artificial diets and different hosts,it was found that the preoviposition period of improving artificial diet decreased significantly after feeding for four generations;the number of males fed by Z.atratus pupae was significantly higher than that of females,oppositely,the number of females in the second and third generations reared by improving diet and the parasitoid original host Monochamus alternatus larvae was significantly higher than that of males.To sum up,by using the substitute host Z.atratus pupae could cause imbalance of sex ratio of the parasitoid offspring,through improving artificial diet formula and reared alternatively by the original host cerambycid,it had a little impact on reproductive biological characteristics after multiple generations of indoor mass rearing,and it could be applied for mass rearing the parasitoid for biocontrol practice.