Propensity of Interstrain Mating in Cytoplasmically Incompatible Strains of the Almond Moth1

Abstract

Males of a strain (US) of Ephestia cautella (Walker) which is reproductively incompatible with strain (I) were caged with I males and virgin I females at various ratios (US♂:I♂:I♀) from 1:1:1 to 24:1:1. Egg hatch decreased from 43.4% at the 1:1 ratio to only 8.1% at the 24:1 ratio, and the total number of progeny per female decreased from 36.1 to 2.1. Calculated competitiveness values showed that I females did not prefer intrastrain mating over interstrain mating. Therefore, releases of large numbers of incompatible males could lead to suppression of E. cautella populations.