Influence of Belated Copulation on the Fecundity and Progeny Sex Ratio of Binodoxys indicus(Subba Rao and Sharma) (Hymenoptera: Braconidae)

Abstract

Belated copulation has been observed as one of the major factors that influence the fecundity and progeny sex ratio in parasitic wasps. A young (0-12h old) female mated with 0-12h old male, Binodoxys indicus produces 131.6±8.08 progeny within 4 days of life. However, older female mated with older male (both 96-108 h old) yields only 89.0±12.54 progeny. The progeny sex ratio (proportion of males) is female-biased (0.36±.03) when the parents were younger (0-12h old) but is male·biased (0.59±0.06) when the parents were older (96-108h old). Therefore, it implies that most of the daughters are produced during earlier phase of reproduction. The analysis of the data shows that only maternal age at copulation influences the total births significantly while both maternal as well as paternal age during copulation influence the progeny sex ratio. The implication of these results is discussed with reference to the maximisation of yield of total births as well as the female births for mass propagation and field release of the parasitoids in biocontrol programmes.