Predatory Capacity and Age-Stage Life Table of Zetzellia mali (Acari: Stigmaeidae) Feeding on Panonychus ulmi on Apple

Abstract

The stigmaeid mite Zetzellia mali is an important phytoseiid-associated predator contributing to the natural suppression of phytophagous mite populations in temperate fruit orchards. Laboratory experiments were conducted to evaluate the predatory capacity and age-stage, two-sex life table parameters of Z. mali when feeding on Panonychus ulmi on apple. Developmental duration, survival rate, fecundity, and predation potential were assessed under controlled environmental conditions. The predator successfully completed its life cycle on all life stages of P. ulmi, demonstrating strong adaptability and feeding efficiency. Nymphal development proceeded through distinct stages with high survival rates under moderate temperature and humidity conditions typical of apple orchard environments. Predation rates increased progressively with developmental stage, with adult females exhibiting the highest consumption of prey mites compared with immature stages and males. Reproductive performance was closely associated with prey availability, with peak oviposition occurring during the early adult period followed by gradual decline in fecundity with age. Life table analysis indicated a positive intrinsic rate of increase, high net reproductive rate, and short mean generation time, reflecting the predator’s capacity for rapid population growth under favorable conditions. Age-stage survival and predation curves demonstrated strong synchronization between predator development and prey availability, highlighting effective functional response to P. ulmi populations. Environmental stability and continuous prey presence significantly enhanced predator survival, reproduction, and overall predation efficiency. The results indicate that Z. mali possesses strong biological control potential against P. ulmi in apple orchards and can contribute to sustainable mite management programs.