Courthsip Behaviour in the Oriental Fruit Fly, Dacus dorsalis under Semi-natural Conditions

Abstract

An investigation was carried out to study the distribution and courtship behaviour of the oriental fruit fly, Dacus dorsalis under semi-natural conditions using a potted citrus plant held inside a perspex cage. The principal site of assembly for mating in Dacus dorsalis on the plant was the under-surface of leaves. When the light intensity was reduced at the 'dusk' period, males aggregated mainly under the leaves and started caIling. Majority of male calling, encounters and copulation attempts between flies occurred on the under-surface ofleaves. Copulation was always initiated on the foliage and never on the 'fruit'. Females were less receptive to males just after mating. Probing with the ovipositor, which is thought to be an important part of the courtship sequence, was the most prominent female sexual behaviour observed.