Predator population density influences oviposition rate in Amblyseius victoriensis Womersley and Typhlodromus doreenae Schicha

Abstract

In a leaf arena study high population densities of Amblyseius victoriensis (Womersley) (7.7/4cm²) and Typhlodromus doreenae Schicha (9.0/4cm²) reduced oviposition from 2.1 and 1.4 eggs/day/ (one predator/4cm²) to 0.6 and 0.7 eggs/day/, respectively. Frequent interference in oviposition behaviour by conspecifics in high density populations is suggested as a mechanism for this phenomenon. Intraspecific relationships of phytoseiid mites have received far less study than phytoseiid-prey interactions. However, they may be important in understanding the dynamics of acarine biological control systems or in the development of mass rearing techniques.