Predatory potential and functional response of Neoseiulus longispinosus (Evans) against Panonychus ulmi (Koch) reared on different apple cultivars
The European red mite, Panonychus ulmi (Koch), has emerged as a major threat to apple production globally, exacerbated by widespread pesticide resistance. This study evaluated the predatory potential and functional response of the predatory mite Neoseiulus longispinosus (Evans) against stage-specific prey densities (3–5 protonymphs, 5–25 deutonymhs or 10–50 adults) of P. ulmi across seven commercially significant apple cultivars: Jeromine, Red Velox, Super Chief, Auvial Early Fuji, Gale Gala, Scarlet Spur II, and Royal Delicious. Laboratory experiments conducted at 25±0.5°C, 14L: 10D photoperiod and 70±5 per cent RH revealed that while larvae remained non-feeding, all other developmental stages exhibited significant predatory activity. The highest net prey-kill rate (C0) was recorded on the Super Chief cultivar (200.78±25.43 mites), while ‘Auvial Early Fuji’ supported the lowest (134.20±21.34 mites). Adult females demonstrated superior predatory efficiency compared to males, with a maximum consumption of 258.44 mites on ‘Super Chief’. Logistic regression confirmed a Type II functional response for all feeding stages across all cultivars, characterized by a declining proportion of prey consumed as initial prey density increased. Predatory performance improved with age; adult females on ‘Red Velox’ exhibited the highest attack rate (0.206 h-1) and the shortest handling time (0.841 h). These findings underscore the influence of host-plant cultivars on predator-prey dynamics and highlight the potential of N. longispinosus as a robust biological control agent for integrated pest management (IPM) programs in diverse apple orchards.