Size Preference and Functional Response of the Reduviid Predator Rhynocoris marginatus Fabricius (Heteroptera:Reduviidae) to its Prey Spodoptera litura (Fabricius) (Lepidoptera:Noctuidae)

Laboratory and field cage experiments were carried out to assess the prey and size preference of the reduviid predator Rhynocoris marginatus Fabricius. It preferred Spodoptera litura (Fabricius) over Euproctis mollifera Walker and Mylabris pustulata Thunberg. The relationship between preference for different sizes of S. litura and the predator, was directly proportional. Functional response of adult female R. marginatus to its most preferred prey size of S. litura revealed that the predator responded positively to the changing abundance of prey and exhibited Holling's second model of functional response. The possibilities of utilising R. marginatus to control S. litura in cotton ecosystem is discussed.