Photoperiodic response of diapause induction in the pine caterpillar, Dendrolimus punctatus

• DOI: 10.1111/j.1570-7458.2005.00345.x
• Publication Date: 2005-10-24T14:30:12Z
• Authors: Lili Huang; Fangsen Xue; Guohong Wang; Ruidong Han; Feng Ge
• Keywords: Voltinism; Overwintering

Abstract The pine caterpillar, Dendrolimus punctatus (Walker) (Lepidoptera: Lasiocampidae), is a multivoltine pest of trees in China, overwintering as larvae. Winter diapause was induced by short day length. critical night length about 10 h 40 min at 25, 28, and 31 °C the field, showing temperature‐compensated induction. Transfer experiments from (L16:D8) to long (L12:D12) or vice versa different times after hatching showed that sensitivity restricted first 14 days; required number for 50% response 25 3.5 days nights but 7.5 nights, indicating are photoperiodically more effective. When four successive were used interrupt long‐night regime development stages versa, results highest photoperiod occurred on 4th−8th day, corresponding second larval instar. Experiments alternating short‐night cycles during period information well could be accumulated. By rearing larvae under conditions other than 24‐h light–dark cycles, we clearly dark (scotophase) played major role determination diapause. Nanda‐Hamner Bünsow failed reveal rhythmic fluctuations with 24 occurrence Therefore, photoperiodic clock D. an hourglass timer damped circadian oscillator.