Parasitism Effects of Sclerodermus alternatusi(Hymenoptera:Bethylidae)on Pre-pupa and Pupa of Monochamus alternatus(Coleoptera:Cerambycidae)
[Objective]Sclerodermus alternatusi is an important biocontrol agent of Monochamus alternatus.To understand the parasitism effects of S.alternatusi on pre-pupa and pupa of M.alternatus and provide more sufficient data in supporting the biocontrol of this beetle.[Method]The parasitism efficiency and off-spring development were investigated when different numbers of foundresses inoculated on the pre-pupa and pupa of M.alternatus under laboratory conditions.Meanwhile,the parasitism rate of the wasp to M.al-ternatus pre-pupa and pupa was also evaluated in the field.[Result]The results showed that both the pre-pupa and pupa of M.alternatus could be parasitized by the bethylid.The parasitism rates to the pre-pupa were 60.71％,85.19％,92.86％,and the parasitism rates to the pupa were 96.67％,96.67％,100％,respect-ively when Sclerodermus alternatusi-Monochamus alternatus ratio was 4∶1,6∶1,and 8∶1.The propor-tions of pre-pupa host could produce wasp offspring were less than 50％;while more than 80％pupa host would produce wasp offspring.The developmental progress of the immature stage were not impacted by the foundress densities,but it was shorted nearly one day when the parasitoid used the pupa as host com-pared to the pre-pupa as host.The numbers of offspring increased with the increasing foundress densities,but the average number of offspring produced from each host was less than 100.In addition,higher pro-portions of male were produced when the maternal wasp parasitizing M.alternatus pre-pupa.The parasit-ism rate to the M.alternatus pre-pupa and pupa was about 30％when the parasitoid adults were released with a parasitoid-host ratio of 8∶1 in the field.[Conclusion]S.alternatusi can successfully parasitize the pre-pupae and pupae of M.alternatus but achieve higher fitness in parasitizing the pupae host.High re-lease ratio of female wasp has a promoting effect on both artificial rearing and field parasitism.
Monochamus alternatusSclerodermus alternatusipupal stagebiological control
万方数据
维普
