Evaluation of biological aspects of the predacious mite, Neoseiulus cucumeris (Oudemans) (Acari: Phytoseiidae) due to prey changes using selected arthropods

Abstract

ABSTRACT Supplying mite predators with alternate feeding stratagems are important in determining their survival and these could play a key role in their use for biocontrol. This paper describes the food habits of predatory mite Neoseiulus cucumeris (Oudemans) in the presence or absence of target insect and acarine pests. The study used well known pests, the stored food mite Tyrophagus putrescentiae (Schrank), the red spider mite Tetranychus urticae Koch, and the western flower thrips Frankliniella occidentalis (Pergande), as prey for the predatory mite. Survival of N. cucumeris was observed in relation to the prey diets offered, prey consumption, fecundity, development time, and adult longevity as influenced by changes in prey were recorded. Significant differences were observed for the types of prey diet used, Ty. putrescentiae was the most suitable prey closely followed by Te. urticae; then F. occidentalis diet. Predation response observed after feeding trials began at a prey density of 15 individuals per predator; N. cucumeris adults displayed higher consumption rates (7.0 and 6.4 nymphs/24 h) for Ty. putrescentiae and Te. urticae, respectively, than for F. occidentalis larvae (4.0/24 h). The duration of the developmental stages of the predatory mites reared on Ty. putrescentiae and Te. urticae were 7.6 and 7.7 days, respectively, compared to 8.5 days when reared on thrips. Total adult female survival periods were higher (30.2 and 28.0 days) when predators were fed these mites than when fed thrips (23.0 days). Survival periods were 27.4, 25.0, and 20.4 days, respectively, for the male predatory mite. Average fecundities of N. cucumeris fed Ty. putrescentiae and Te. urticae were 3.8 and 3.4 eggs after 24 h, respectively, compared to 2.2 eggs when fed thrips. Respective oviposition periods were 20.4, 18.0, and 13.4 days. After transfer to a new prey host, adult N. cucumeris of which the parental stock had been fed F. occidentalis, showed preference for Ty. putrescentiae and Te. urticae. Predatory mites for whom the parent generation had been reared on Ty. putrescentiae and Te. urticae also accepted F. occidentalis as substitute prey but inadequate predation was apparent, as indicated by reduced egg production, growth period, and survival. Although relatively short, the periods measured were sufficient to reveal differences linked to the initial and previous diets. The predatory mite N. cucumeris is a promising biological control agent for thrips, spider mite, and mold mite because it can feed and survive on alternative nutritional sources when prey is absent or scarce.