烟蚜茧蜂寄生对烟蚜生长发育和繁殖的影响

【目的】为探究烟蚜茧蜂Aphidius gifuensis对烟蚜Myzus persicae寄生后烟蚜生长发育和繁殖影响及其在烟蚜防控中的作用。【方法】采用室内叶片培养皿法，测定了不同龄期烟蚜(1-4龄若蚜及成蚜)被烟蚜茧蜂寄生后烟蚜当代(F₀)及后代(F₁)的发育历期、寿命、产仔量。【结果】烟蚜1龄若蚜被烟蚜茧蜂寄生后，1龄若蚜历期受到显著影响，较未被寄生对照缩短了0.65 d (33.00%)，而2-4龄若蚜期和成蚜历期未受显著影响；2龄若蚜被寄生后，4龄若蚜和成蚜历期均受到显著影响，较未被寄生的对照分别缩短了1.50 d (100.00%)和0.83 d (100.00%)，而2和3龄若蚜期未受显著影响；3龄若蚜被寄生后，4龄若蚜和成蚜期均受到显著影响，较未被寄生对照分别缩短了1.50 d (100.00%)和0.83 d (100.00%)，而3龄若蚜期未受显著影响。2龄若蚜被寄生后烟蚜的寿命和产仔量均受到显著影响，寿命较未被寄生对照缩短了8.39 d(54.00%)，每雌产仔量较未被寄生对照减少了48.67头(100.00%)。此外，2-3龄若蚜被寄生后其后代(F₁)1龄若蚜历期受影响最大，较未被寄生烟蚜后代1龄若蚜期缩短了0.80 d(40.00%)，其F₁代平均寿命较未被寄生烟蚜后代平均寿命延长了5.72 d(41.20%)，但其产仔量与对照差异不显著。【结论】不同龄期烟蚜被烟蚜茧蜂寄生后，其发育历期和寿命比未被寄生的缩短，产仔量比被未寄生的少，但其F₁代平均寿命比未被寄生后代烟蚜的长且其产仔量未受显著影响。当代2龄若蚜期是控制烟蚜增长的关键时期。这些结果对确定烟蚜茧蜂防治烟蚜适期及认识其机理具有重要参考意义。

Effects of parasitization byAphidius gifuensis (Hymenoptera: Aphidiidae) on the growth,development and reproduction ofMyzus persicae(Hemiptera: Aphididae)

【Aim】 This study aims to clarify the effects of parasitization by Aphidiusgifuensis on the growth, development and reproduction of the green peach aphid, Myzuspersicae, and its role in the control of this aphid. 【Methods】 After M. persicae atdifferent developmental stages (the 1st, 2nd, 3rd and 4th instar nymph and adult) wereparasitized by A. gifuensis, the developmental duration, life span and litter size of theF₀ and F₁ generations of M. persicae were evaluated by breeding in Petri dish using tobaccoleaves in the laboratory. 【Results】 After the 1st instar nymphs of M. persicae wereparasitized by A. gifuensis, the developmental duration of the 1st instar nymph of M.persicae was significantly shortened by 0.65 d (33.00%) as compared with that of theunparasitized control, while the developmental duration of the 2nd instar nymph to adult ofM. persicae was not significantly affected. After the 2nd instar nymphs of M. persicae wereparasitized by A. gifuensis, the developmental duration of the 4th instar nymph and adultof M. persicae was significantly shortened by 1.50 d (100.00%) and 0.83 d (100.00%),respectively, as compared with that of the unparasitized control, while the developmentalduration of the 2nd and 3rd instar nymphs of M. persicae was not significantly affected.After the 3rd instar nymphs of M. persicae were parasitized by A. gifuensis, thedevelopmental duration of the 4th instar nymph and adult of M. persicae was significantlyshortened by 1.50 d (100.00%) and 0.83 d (100.00%), respectively, as compared with that ofthe unparasitized control, while the developmental duration of the 3rd instar nymph of M.persicae was not significantly affected. After the 2nd instar nymphs of M. persicae wereparasitized by A. gifuensis, their life span was significantly shortened by 8.39 d (54.00%)and the litter size per female was decreased by 48.67 individuals (100.00%), as comparedwith those of the unparasitized control. Additionally, after the 2nd and 3rd instar nymphsof M. persicae were parasitized by A. gifuensis, the developmental duration of the 1stinstar nymph of M. persicae offspring (F₁) was shortened by 0.80 d (40.00%), and thisdecrease was more significant for the 1st instar nymph of M. persicae offspring (F₁) thanfor the other instar nymphs. The average life span of the parasitized M. persicae offspring(F₁) significantly increased by 5.72 d (41.20%) as compared with that of the unparasitizedaphid offspring, while their litter size was not significantly different from that of thecontrol. 【Conclusion】 After M. persicae at different developmental stages wereparasitized by A. gifuensis, the developmental duration and life span of M. persicae weresignificantly shortened, and its litter size was significantly decreased as compared withthat of the unparasitized aphids. The average life span of the offspring (F₁) ofparasitized aphids was longer than that of the offspring of the unparasitized ones, whilethe litter size of the offspring of the parasitized and unparasitized aphids was notsignificantly different. The 2nd instar nymph of M. persicae is the key stage forcontrolling this aphid by A. gifuensis. These results provide important data fordetermining the optimal control time and understanding the underlying mechanism for thecontrol of M. persicae by A. gifuensis.