The relation between food, age and flight in the Rutherglen bug, Nysiusm vinitor (Hemiptera : Lygaeidae)

Abstract

The relationships between food, egg-laying, age, and flight were studied with the aim of providing a better understanding of the causal factors of displacement flights in N. vinitor. The distinction in N. vinitor between "fliers" and "non-fliers" is, most probably, a reflection of the environment. Thus, an increased proportion of individuals taking off and of distinctively prolonged flights were a response to inadequate food either during the nymphal or adult stage. Shortage of water during the adult stage resulted also in increased flight activity. The quality of the food consumed by the nymphs rather than its quantity affected the behavioural flight response of emerging adults. Immature females, whether virgin or not, had different flight responses from egg-laying females and are probably the true migrants of the species. Displacement flights in N. vinitor are always triggered by adverse conditions in the nymphal or adult stage, but the type of flight changes as females become older; flights are migratory in the immature females and dispersive in the mature ones.