Absence of intraspecific interference during feeding by the predatory ladybirds Chilocorus spp. (Coleoptera: Coccinellidae)

Abstract. 1. The hypothesis was tested that intraspecific behavioural interference does not adversely affect the feeding behaviour of adults of three predatory coccinellid species, Chilocorus nigritus (F.), C.bipustulatus (L.) and C.infernalis Mulsant, at densities found under field conditions.
2. Feeding rates on mature oleander scale Aspidiotus nerii Bouché were evaluated by two methods at various predator densities. Proportion of the population dispersing was also measured for one of the species.
3. Feeding rate did not decrease and dispersal did not increase with increasing predator density. No significant behavioural interference that might have reduced predatory efficiency was observed, counter to assumptions on which published interference models are based.
4. Results here help to explain the relative importance of parasitoids and predators in the effective control of red scale Aonidiella aurantii (Mask.). The results also provide guidelines for release of these bio-control agents.