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。
ne hundred 4th instars of the Masson's pine
caterpillar were treatd withhigh(1×10_8 conidia/ml)and low(4×10_6)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.
出处
《安徽农业大学学报》
CAS
CSCD
1996年第3期381-391,共11页
Journal of Anhui Agricultural University
基金
国家"八五"攻关项目
关键词
真菌杀虫
虫生真菌
马尾松毛虫
生殖生理
产卵量
Entomogenous fungi Dendrolimus punctatus Nutritional
ph ysiology Reproductive physiology Food consumption Fecundity Increase rate Starvation