Nn the repriductive diapause in a predatory ladybird Cheilomenes sexmaculata (Fabricius, 1781) (Coleoptera, Coccinellidae)
The ability to enter reproductive diapause was experimentally studied in females of the laboratory population of a predatory ladybird Cheilomenes sexmaculata originated from individuals collected in Nepal in a region of subtropical monsoon climate. The experiment included 12 regimes, i. e. combinations of 2 temperatures (20 and 24 °C), 3 photoperiods (day lengths of 10, 12, and 14 h), and 2 diets (the green peach aphid Myzus persicae and eggs of the grain moth Sitotroga cerealella ) . Females with undeveloped ovaries and well developed fat body were considered as diapausing. The proportion of diapausing females was signiﬁcantly dependent only on temperature being 0.8% at 24 °C and 7.4% at 20 °C. Although found in only a small fraction of the studied population, the ability to enter reproductive diapause (as suggested by literature data) possibly was an important prerequisite for Ch. sexmaculata spread northwards to the temperate zone.