Survival, development and fecundity in Euseius finlandicus, Typhlodromus pyri and Kampimodromus aberrans (Acari, Phytoseiidae) feeding on the San José scale Quadraspidiotus perniciosus (Coccina, Diaspididae).

Studies on juvenile survival, development and reproduction of Euseius finlandicus Oudemans, Typhlodromus pyri Scheuten and Kampimodromus aberrans Oudemans feeding on crawlers of the diaspidid San José scale Quadraspidiotus perniciosus Comstock were conducted in the laboratory at 25 ± 1°C, 65 ± 5% RH and 16 h photoperiod. Immature life stages as well as adult females readily accepted crawlers as prey. All predatory species preying upon scale crawlers were able to complete development and to sustain reproduction during a 10-day-period. Immatures of E. finlandicus and K. aberrans had a low juvenile mortality, whereas nearly 50% of T. pyri protonymphs died. Mean development from larva to adult took 5.6 days in E. finlandicus, 13.2 days in K. aberrans and 17.4 days in T. pyri. E. finlandicus had a higher fecundity (0.7 eggs/day/female) than T. pyri (0.5 eggs/female/day) and K. aberrans (0.4 eggs/female/day). However, San José scale crawlers must be considered a suboptimal prey. Its nutritional value is discussed in relation to that of more adequate food sources. Data on development and fecundity are also discussed in relation to other phytoseiid species feeding on armoured scale insects. [ABSTRACT FROM AUTHOR]