White Moth Zhou Tetrastichus Host

In order to probe the amount of the host species of Chouioia cunea Yang(Hymenoptera: eulophidae) in nature,biology and population dynamic of the hosts,and the generation number and population dynamics of Chouioia cunea Yang, thehost species of Chouioia cunea Yang were studied in Yantai,Tianjin andQinghtuangdao in l998. Based on the results required previously, in 1999, thegeneration number and population dynamic of Chouioia cunea Yang, The lifehistory and population dynamic of its main hosts were investigated in forests. theconclusions are as follow:l.The chalcid has 7 generations per year in Yantai region. The adult chalaids of thefirst generation emerges in the mid-May, and the mature larve of the last generationoverwinter in the host pupa during early-November the chalcids can develop in awhole year without diapause or dormancy. the developing period is17.6—48.1days.2.In nature, many species of insects, including some common forest defoliationpest insect, are the second hosts of Chouioia cunea Yang. because os the successivedevelopment of the different species of second hosts pupa, the number andparasitical rate of chalcids in nature can be increased largely when fall webwormsare controlled by our releasing large number of manual reared chalcids. not onlycan good results be obtain for controlling fall webworm at that period of releasingchalcids, but also sustainable controlling effect can be achieved in that chalcids canparasitize the second hosts and maintain a high level of population during theinterval of two generations pupa of fall webworm.3.The number of chalcids has three peaks during a who1e year in the seriouslydamaged forests. The reason is that chalcids paratize the overwinter pupa, the firstgeneration pupa and the second ones of fall webworm. So population density ofchalcids deponds on the population density of fall webworm.4.Cluster analysis shows when7 species of hosts of chalcids, 16 samples,areclassified into 4 groups, every sample coming from the same family almost belong7 白蛾周氏啮小蜂寄主的研究:AbstracttOM saxne rOUp．Tins means山at山ed＆rent between di＆rent smples Is verylittle．Howeve二 eme侣ingnUIneL sex rate andthe female number ofchalclds veryInyely．5．houghMlwebworm could be coddolled by our releasing chalclds In fores叮andthe population Is decreased greatlX the chalclds can still extendtheirpopulatlonbyparatlzingthe secondhosts because chalclds have manyspecles ofsecond hosts．In the same wap When fal webworm outbreak again,the chalcldscanparatlze and cofitrol them once more．The chalclds can co血Inuously colltrol彻lwebworm for a long time as a main n眈肌 enemy offall webworm．6．Though the chalclds have many second－hosts,and thedeveloping period ofdifferent spedes ofp叩a Is comolnt,the high density ofchalcldspopulatlon can'tbekeptbecause the number of＊the second hosts Is so few The variation of thechalclds number almost depends on the density offall webworm In forests．Duringthep叩aperlod offall Webworm,the population ofchalclds keeps a high level,While during otherperlods,It keeps a very low level。Hence,the mixed forestslllCllldlflgthapy SpCCICS OftrCCS ShollldbCpl�'�Cd SO thatthC lflSCCt dlVCYSltydridthe number of＊the second hosts could be Increased to mal血am a high level ofchalcldpopulatlon for co血oiling forestpest Insects,fall webworm．...