不同品系赤眼蜂对烟青虫卵的寄生选择性

采用棚室笼罩试验，研究了松毛虫赤眼蜂和螟黄赤眼蜂的不同品系对不同卵龄烟青虫卵的寄生选择性、松毛虫赤眼蜂HJS品系对烟草不同叶位、叶面上的烟青虫卵及不同植物（辣椒和烟草）上的烟青虫卵的寄生选择性。结果表明，松毛虫赤眼蜂HJS、YYS品系和螟黄赤眼蜂JDM品系对0～12h烟青虫卵的寄生率显著高于12～36h的卵；而螟黄赤眼蜂GGM品系对该二卵龄烟青虫卵的寄生选择性无显著差异。不论位于叶正面、叶背面还是整叶上的卵，松毛虫赤眼蜂HJS品系均对倒10～12叶位的卵寄生选择系数最高，其次为倒13～15叶，对倒1～6叶均较低，这与烟青虫产卵对叶位的选择不同；HJS对所有叶位叶正面烟青虫卵的寄生选择系数均高于对背面的，并以倒1～3和倒4～6叶位最为明显，且HJS对叶正面卵的寄生倾向和程度与烟青虫雌蛾在该叶位正面产卵的倾向及程度存在差异，该差异因叶位不同而不等。HJS对辣椒上烟青虫卵的寄生选择系数较高，而烟青虫偏好产卵于烟草。

Oviposition Preference of Trichogramma Strains to Helicoverpa assault Eggs

Parasitic preferences of .Trichogramma dendrolimi. and . T. chilonis. strains to differently aged eggs of tobacco budworm, .Helicoverpa assault,. were investigated in cages. And that of T. dendrolimi HJS strain to H. assault eggs on different leaf positions and leaf surfaces of tobacco, and that on pepper and tobacco was also studied at the same situation. Results showed that: parasitisms of T. dendrolimi HJS and YYS strains and T. chilonis JDM strain to the 0-12h eggs were significantly higher than their corresponding parasitisms to the 12-36h eggs. Wihle parasitisms of T. chilonis GGM strain to the two kinds of eggs did not differ significantly. No matter the eggs were on the upside, on the underside, or on the whole tobacco leaves, T. dendrolimi HJS strain preferred eggs on the 10th-12th leaves from the top, followed by those on the 13th-15th leaves and on the 1st-6th leaves from the top. This parasitic preference of leaf position differed from the oviposition preference of tobacco budworm. Among all leaf positions, HJS strain preferred host eggs on the leaf upsides to that on the undersides, and the difference was especially obvious between the 1st-3rd and the 4th-6th leaves from the top. Such preferences of T. dendrolini HJS strain differed with that of tobacco budworm's oviposition preference. As to different host plants, HJS strain preferred to oviposit in the host eggs on pepper, but tobacco budworm preferred to oviposit on tobacco.