【摘要】 用高浓度（１×１０　８分生孢子／ｍｌ）和低浓度（４×１０　６）球孢白僵菌孢悬液处理４龄马尾松毛虫幼虫，在处理后至开始侵染死亡的１５ｄ内，高浓度处理减少松针损失４４．４％，低浓度处理减少１９．６％，消化率无显著差异，但食物利用率和转化率比对照低。饲养未死于侵染的残余幼虫至化蛹，其侵染率、化蛹率、羽化率、性比及蛹重有随着处理浓度的增加而降低的趋势。实验结束时检查受精卵数，高浓度、低浓度处理组和对照组分别为１２８３、４８２６和９６０４粒，实验种群的实际增长率分别为１２．８３、４８．２６和９６．０４。种群增长率因高浪度和低浓度处理而分别降低８６．６％和４９．８％，此外，还研究了饥饿对虫生真菌侵染４龄幼虫的影响。将幼虫分别喷以球孢白僵菌、金龟子绿僵菌和粉拟青霉后，饥饿处理１、２、３和４ｄ后正常饲养，各处理和正常饲养的对照间的侵染死亡率无显著差异。更多还原

【Abstract】 ne hundred 4th instars of the Masson’s pine caterpillar were treatd withhigh（1×10₈ conidia/ml）and low（4×10₆）concentrations of Beauveria bassiana conidialsuspension,reared routinely,and weights of pine needles consumed, feces as well as each lar-va were recorded daily.The result showed that during the period from treating to the 15thday when death due to infection began,the needle consumption（Y）of each larva was corre- lated to the day（x）posttreatment in the following forms:for high concentration treatment,Y2=41.55-25.52x2+4.44x;for low concentration treatment,Y1=41.82-24.86x1+5.41x;for control,Y0=84.53-36.69x0+6.85x;Based on the above models,loss of pineneedles by the caterpillar was decreased due to Beattveria bassiana infection during the periodby 44.4% for the high concentration and 19.6% for low concentration.There was no sig- nificant difference between approximate digestibilities between the 2 treatments and the con- trol. Efficiencies of conversion of ingested fcod and effiencies of conversion of digested foodof the treatments were lower than those of the control,and once showed negative values,in-dicating that the infection did not affect the digestibility and a portion of food was convertedinto energy for severe defence reaction.The surviving larvae were reared and allowed to pupate for further development obser-vation.Pupation rates, emergence rates of the pupae as well as sex and weight of the pupaewere recorded.All the results indicated an obvious tendency of reduction as treatment con- centration increased.Male and female pupae were paired and allowed to emerge and depositeggs,The result showed a reduction of oogenesis as the concentration increased.Number offertilized eggs of the treatments and the control were estimated after the whole experimentcompleted.They were 1283,4826 and 9604 for high,low concentration and control,respec-tively;The actual increase rate of the experimental population were determined to be 12.83,48.26 and 96.04,respectively.Cosequently,reduction of increase rate of the caterpillar popu- lation by the high concentration treatment was estimated as（96.04-l2.83）/96.04×100%=86.6%and that by low 49.8%.In addition,Effect of starvation on fungal infection of the 4th instars was tested.Theywere sprayed with conidia of B. bassiazia,M.anisopliae and P,farinosus and then starved for 1,2,3 and 4 days before fed routinely.No significant difference was found between infec- tions of the treatments and non-starvation control.更多还原