1984年晚稻稗草上三种水稻主要同翅类害虫卵及其被寄生情况初步调查

1984年晚季在水稻田内系统调查白背飞虱,褐飞虱,黑尾叶蝉在稗草和水稻上的着卵量及其卵寄生情况。结果表明:(1)白背飞虱卵晚稻中期数量大,后期数量极少。田间稗草和田埂稗草上产卵量大,其卵量分别随时间的延长而减少,即呈直线负相关,R 分别是-0.826(P<0.05)和-0.779(P<0.05),而且消长趋势较一致(T=0.0003,P>0.1)。(2)褐飞虱卵量消长是中期数量少,后期数量突增,水稻上产卵量更多。但在水稻收割期,则更趋于稗草上产卵,尤其是在田埂稗草上产卵。(3)黑尾叶蝉卵量也是中期数量大,后期数量极少。田间稗草和水稻上产卵量较大,卵量和时间呈函数关系,直线相关系数分别是-0.779(P<0.05)和-0.958(P<0.01)。两直线斜率差异不显著(T=0.013,P>0.1)。(4)稻田稗草有较多的白背飞虱和黑尾叶蝉卵,而且卵平均寄生率很高,分别为48.6%和78.9%;卵出蜂数量也比田埂稗草和水稻高得多。

PRELIMINARY INVESTIGATIONS OF BIONOMICS OF EGGS OF THREE DOMINANT SPECIES OF HOMOPTEROUS RICE PESTS AND THEIR EGG PARASITISM

Preliminary investigations on the bionomics of the eggs of three domi- nant species of homopterous rice pests have been made.These three species were white backed rice planthopper,Sogatella furcifera(Horvath),brown planthopper,Nilaparvata lugens,and rice leafhopper,Nephotettix cincticeps (Uhler).The results are summarized as follows: 1.White backed rice planthoppers more frequently lay eggs in the tissue of barnyard grass in fields and on ridges than in the tissue of rice. Both egg populations in barnyard grass in fields and on ridges tend to reduce with time.Their correlation coefficients(R)are-0.826(P<0.05)and -0.779(P<0.05)respectively.By comparing the two slopes,the difference between these two populations is not significant(T=0.0003,P>0.1). 2.Inversely,brown planthoppers lay more eggs in the tissue of rice than in the tissue of barnyard grass.However,at rice-ripening stage they laid many more eggs in the tissue of barnyard grass,especially in the tissue of the ridge plants,than in the tissue of rice. 3.Rice leafhoppers laid over seven times as many eggs in the tissue of rice and barnyard grass inside the fields as in the tissue of barnyard grass on the ridges.In the fields,the negative trend of the number of eggs in rice and in barnyard grass is a function of time.Their correlation coeffi- cients(R)are-0.779(P<0.05)and-0.958(P<0.01)respectively.The slopes of these 2 trends do not differ significantly from each other(T=0.013, P>0.1). 4.The percentage of egg parasitism in rice leafhopper was much higher than in the other two species.More egg parasites were reared from the eggs in the tissue of barnyard grass in the field than those from rice and barnyard grass on the ridges.