白蛾周氏啮小蜂滞育诱导及滞育后发育

本研究针对人工繁育白蛾周氏啮小蜂Chouioia cunea Yang过程中出现的小蜂滞育现象, 对其滞育诱导的光周期反应及敏感光照虫态进行了调查。结果表明: 沈阳地区的白蛾周氏啮小蜂属长日照型昆虫, 以老熟幼虫进入滞育状态, 但在不同的温度条件下诱导滞育的临界光周期不同, 在18℃时诱导滞育的临界光周期处于13L∶11D和14L∶10D之间; 在21℃和24℃时诱导滞育的临界光周期变短, 处于12L∶12D和13L∶11D之间。白蛾周氏啮小蜂滞育诱导的敏感光照虫态为幼虫期, 且以幼虫的后期最为敏感, 但整个幼虫期接受短光照对滞育的形成更为有利。通过观察白蛾周氏啮小蜂滞育后在18℃, 21℃, 24℃和30℃的恒温条件下的发育历期, 由最小二乘法计算出白蛾周氏啮小蜂老熟幼虫滞育后发育起点温度和有效积温分别为14.60±0.31℃和209.38±8.72日·度。这些结果可为进一步研究白蛾周氏啮小蜂的种蜂长期保存技术和指导商品蜂生产, 正确把握放蜂时机提供理论依据。

Diapause induction and post-diapause development in Chouioia cunea Yang (Hymenoptera: Eulophidae)

Photoperiod response of diapause induction and the photo-sensitive stage in Chouioia cunea Yang were investigated. The photoperiodic response curves under 24-h light-dark cycles showed that the species is a typical long-day species, entering diapause as mature larvae. The critical photoperiod for diapause induction was estimated to be between 13L: 11D and 14L: 10D at 18℃, and between 12L: 12D and 13L: 11D at 21℃ and 24℃. The late instar larvae were most sensitive to photoperiod. However, the short day light received at all larval stages was also important for the increase of their diapause rate. The developmental duration for post-diapause development of C. cunea was determined by exposing diapause larvae to different constant temperatures (18, 21, 24 and 30℃). The results showed that the threshold temperature and effective accumulative temperature for post-diapause development of mature larvae were 14.60 ±0. 31℃ and 209. 38 ± 8. 72 day-degrees, respectively. These results may provide a theoretical basis for long-term preservation, commercial production and release time of C. cunea.