First evidence for photoperiodic regulation of the life cycle in a millipede species, Polydesmus angustus (Diplopoda: Polydesmidae)

摘要: The hypothesis that the periods of dormancy previously described in millipede Polydesmus angustus may be photoperiodically induced diapauses was tested experimentally. In this species, biennial individuals exhibit two successive dormancy: aestivation penultimate stadium (stadium VII) and reproductive adults, which emerge autumn. It first established is not a thermally controlled state quiescence. When adults emerging autumn were kept at 16 °C under natural photoperiod, their reproduction delayed for several months comparison with spring similar temperatures. This indicates begins period diapause. Further experiments provided evidence photoperiodic induction adult millipedes reared short day length (L:D 12:12 h) throughout development, they required more time to reproduce than long 16:8 same Photoperiod influenced females, but no significant effects detected males. On other hand, VII markedly longer L:D h both sexes, strongly suggests also by photoperiod. However, on duration varied among individuals, some showed response days. study document regulation life cycle class Diplopoda, trait common classes terrestrial arthropods.