Mating behaviour of the predaceous ladybird, Harmonia dimidiata

We studied the mating behaviour of the predaceous ladybird beetle, Harmonia dimidiata (Fabricius) (Coleoptera: Coccinellidae). The courtship behaviour of the male involves the secretion from the tibio-femoral joints of its hind-legs of yellow coloured reflex blood containing the alkaloid harmonine, which is usually the first line of defence of this ladybird. In this case, this reflex blood also functions as a nuptial gift from the male, which is edible and facilitates mating. The amount of reflex blood offered as a nuptial gift decreases with each subsequent mating. Mating in H. dimidiata was prolonged and initially increased before subsequently decreasing with each subsequent mating. This information could be useful for the mass rearing of this species in the laboratory.