Diapause and post-diapause quiescence demonstrated in overwintering Harmonia axyridis (Coleoptera: Coccinellidae) in northwestern Europe

作者：Raak Van den Berg C Lidwien^*; De Jong Peter W; Hemerik Lia; Van Lenteren Joop C

来源：EUROPEAN JOURNAL OF ENTOMOLOGY, 2013, 110(4): 585-591.

DOI：10.14411/eje.2013.079

• Coleoptera
• Coccinellidae
• Harmonia axyridis
• invasive species
• hibernation
• diapause
• quiescence
• pre-oviposition period
• semi-field experiment

The Asian ladybird Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) is regarded as an invasive species in many parts of the world. In a previous study we hypothesised that H. axyridis enters diapause at the end of October and then shifts to a quiescent state in December in northwestern Europe. In the present study we test this idea of a short, early period of diapause by sampling beetles from their hibernation sites immediately after their migratory flights in October, subsequently keeping them in outdoor cages, and then, after certain time-intervals, measuring the pre-oviposition time under optimal egg-laying laboratory conditions at 25 degrees C. We did this at both short (12L) and long (16L) photoperiods, since a photoperiodic response is an indicator of true diapause, rather than quiescence. A significant, albeit small, difference in pre-oviposition period between the two photoperiods, which disappears in December, corroborates our earlier hypothesis that the ladybirds are in a state of diapause until mid-December. Compared with that of native ladybirds the diapause of H. axyridis generally is relatively short and weak; moreover, it appears to have become shorter over the last decade. This flexibility in diapausing behaviour may be an important factor that contributes to the invasive success of H. axyridis.

• 出版日期2013