The effect of aging and food source of males on the reproductive potential of Orius laevigatus (Hemiptera: Anthocoridae)

Orius spp. are polyphagous predators that are widely used as biological control agents of thrips and other small arthropods. Research has increasingly focused on the rationalization of the mass production of these predators. The objective is to develop cost effective foods which could lower the production costs and hence promote the use of these biological control agents. The suitability of a diet is evaluated by assessing the developmental and reproductive performance of the produced insects. When assessing reproductive potential, the role of males is often neglected, although they may have a significant impact on the reproductive output of their female mates. In this study the effect of age and diet of males on the reproductive capacity of Orius laevigatus was investigated. The tested diets consisted of eggs of the Mediterranean flour moth Ephestia kuehniella and an egg-yolk based artificial diet. Regardless of their diet, virgin females did not produce any mature oocytes, indicating that mating is required to complete ovarian development. When both males and females were offered the artificial diet, male age had a significant effect on female oocyte counts. Virgin females that were mated with 0-day-old virgin males produced fewer offspring than those mated with 8-day-old virgin males. In contrast, male age did not affect fecundity when the males were fed E. kuehniella eggs. The implications of these findings for the mass production of O. laevigatus are discussed.