Altitudinal Variation of Pupal Diapause in the Flesh Fly, Boettcherisca nathani (Diptera : Sarcophagidae), from the Nepalese Himalaya

The sarcophagine flesh fly, Boettcherisca nathani LOPES is widely distributed from Malaysia to Pakistan including the Indian subcontinent and Sri Lanka. In the Nepalese Himalaya, B. nathani is commonly found from lowlands to highlands up to 2, 500 m above sea level. Six colonies of B. nathani, each originated from a female collected in Nepal, were investigated for their photoperiodic responses inducing pupal diapause. Three colonies derived from the mountainous areas, Bn (Tistung), Bn (Jubing) and Bn (Ghandruk), entered pupal diapause to some extent (7.7 to 58.7%) under short day photoperiodic regimes at 20℃. The critical day length was 12 h 45 min in Bn (Tistung) and 12 h 30 min in Bn (Jubing) and Bn (Ghandruk), respectively. Three colonies from the lowlands of Terai plain and Kathmandu valley, Bn (Nijgahr), Bn (Kathmandu) and Bn (Godawari) were virtually "non-diapausing". In these three lowland colonies, less than one percent of pupae entered diapause at 12L : 12D and 10L : 14D, or 10L : 14D, and no diapause was observed in photoperiods from 16L : 8D to 9L : 15D. "Nondiapausing" colonies originating from the foot of Himalayas seem to have a potential, though limited to photoperiodically control diapause.