拟青霉菌代谢产物对菜粉蝶幼虫的生物活性

淡紫拟青霉(Paecilomyces lilacinus)甲醇萃取物柱层析活性馏分DM6和拟青霉(Paeecilomyces sp.)菌株X1甲醇萃取物柱层析活性馏分X1M5对菜粉蝶Pieris rapae(L.)4龄幼虫具有较强的选择性和非选择性拒食作用,处理后24h选择性AFC50分别为5.8652mg/mL和3.5239mg/mL,非选择性AFC50分别为9.0095mg/mL和14.0234mg/mL。饲喂法、注射法、点滴法测定结果表明,DM6和X1M5对菜粉蝶4龄幼虫具有较强的毒杀活性,其中注射法处理后72h,DM6和X1M5对菜粉蝶4龄幼虫的LD50分别为0.1846μg/头和0.6784μg/头。DM6和X1M5以5.0mg/mL饲喂法处理菜粉蝶3龄幼虫后,试虫生长发育受到强烈的抑制作用,发育抑制率分别为73.34%和63.30%。这些结果对于进一步研究拟青霉菌杀虫活性成分具有重要参考意义。

Insecticidal activities of metabolites from two Paecilomyces spp. to the small cabbage white,Pieris rapae

The insecticidal activities of metabolites produced by Paecilomyces lilacinus and Paeecilomyces sp.X1 strain isolated from the infected aphids, against the small cabbage white, Pieris rapae (L.) (Lepidoptera: Pieridae) were reported in this paper. The methanol fractions were separated in the extensive separation by silica gel column and the subsequent biological activity tests showed that the 6th fraction of P.lilacinus(DM6) and the 5th fraction of Pieris sp. X1(X1M5) were their active fractions. The biological activity for P. rapae 4th instar larvae was investigated and the results showed that the AFC50 of DM6 and X1M5 were 5.865 2 mg/mL and 3.523 9 mg/mL in choice test and 9.009 5 mg/mL and 14.023 4 mg/mL in no-choice test after treatment 24 h, respectively. The active fractions DM6 and X1M5 may possessed strong toxicity against P. rapae 4th instar larvae by feeding, injection and topical application method, for example the LD_ 50 of DM6 and X1M5 were 0.184 6 μg/larva and 0.678 4 μg/larva after treatment 72 h by injection method. The results showed the development inhibited rate (DIR) for 3rd instar larvae was 73.34% and 63.30% for DM6 and X1M5 respectively, by feeding contaminated leaves on the concentration of 5.0 mg/mL.