Diapause Programming with Variable Critical Daylength under Changing Photoperiodic Conditions in Mamestra brassicae (Lepidoptera : Noctuidae)

概要

論文の詳細を見る
Mamestra brassicae (Linnaeus) can be regarded as a long-day insect, because a long winter diapause (WD) is induced by short daylengths while nondiapause and short summer diapause are predominant under intermediate (14.5 h) and long (>15 h) daylengths, respectively. However, LD16 : 8 (16 h light : 8 h dark) dramatically enhanced WD induction and LD12 : 12 averted WD when followed by LD14 : 10 after the egg or early larval stages. Only three cycles of LD16 : 8 in the first larval stage followed by LD14 : 10 resulted in 100% WD. In the early larval stage, a shift from LD18 : 6 to 15 : 9 as well as from LD15 : 9 to 14 : 10 gave a high incidence of WD, but that from LD16 : 8 to 15 : 9 prevented WD. Increasing shift below the critical daylength (e.g., from LD10 : 14 to 13 : 11) did not avert WD. These results could not be explained either by a response to the direction of daylength change or by a response involving stepwise processes. We hypothesize that, within a certain range of photoperiod, the critical daylength for the programming of pupal development changes with the daylength in the early developmental stages. The incidence and intensity of diapause under simulated 'natural' photoperiodic conditions suggested the significance of daylength change in the fine tuning of the seasonal life cycle.
日本昆虫学会の論文
1998-12-25