Bottom-up effects of strawberry cultivar resistance on the demographic and predatory performance of Neoseiulus californicus (Phytoseiidae) against Phytonemus pallidus (Tarsonemidae)

Screening of chilli (Capsicum annuum L.) germplasm for resistance to broad mite, Polyphagotarsonemus latus (Banks) under field conditions

Chilli (Capsicum annuum L.) is an economically important spice and vegetable crop cultivated extensively in tropical and subtropical regions of the world. However, its productivity is severely constrained by several insect and mite pests, among which the broad mite, Polyphagotarsonemus latus (Banks), is a major pest causing leaf curling, stunted growth, flower drop and substantial yield losses. Developing resistant cultivars offers an eco-friendly and sustainable approach for broad mite management. Therefore, field investigations were conducted during kharif 2023 and 2024 to evaluate sixteen chilli genotypes, including the susceptible check Byadgi Dabbi, for resistance against broad mite infestation. The study aimed to assess genotypic variability and identify resistant sources for future breeding programmes. During 2023, mean mite infestation was 2.96 mites per leaf, ranging from 2.30–4.02 mites per leaf. Higher populations were recorded on Sadabahar, Rasgulla and Byadgi Kaddi, whereas Phule Jyoti and Phule Mukta exhibited lower infestation levels. Mite incidence commenced at 45 days after transplanting (DAT), reached its peak at 120 DAT and declined thereafter. In 2024, infestation ranged from 1.98–3.78 mites per leaf, with maximum incidence observed at 90 DAT. Sadabahar remained highly susceptible, while Phule Jyoti, RHRCH 8-2 and Phule Mukta consistently recorded lower mite populations. The pooled mean infestation was 2.79 mites per leaf (2.14–3.90). Based on resistance categorisation, 2 genotypes were identified as resistant, 8 as moderately resistant, 3 as moderately susceptible and 3 as susceptible, indicating substantial genetic variability and providing valuable sources for resistance breeding and integrated pest management programmes in chilli.

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.

Combined use of Beauveria bassiana and the predatory mite Neoseiulus californicus to suppress Tetranychus urticae on greenhouse-grown sweet pepper

Predatory mites and invertebrate-pathogenic fungi are important biological control tools for managing populations of the two-spotted spider mite, Tetranychus urticae, in horticultural field crops. Here, we evaluated strategies for the combined use of a mite-pathogenic strain of Beauveria bassiana and Neoseiulus californicus to suppress T. urticae populations on sweet pepper plants. First, we compared the performance of both biocontrol agents, applied alone or in combination, under greenhouse conditions. A decline in T. urticae populations was observed 7 days after the release of the predatory mite (53–62%), the application of fungal conidia (77–81%), and their combined use (73–81%). However, in the combined treatment, N. californicus abundance was lower on plants sprayed with B. bassiana than on unsprayed plants. We then evaluated a temporal selectivity strategy in lab and greenhouse conditions, releasing the predatory mite at varying intervals after fungal application, to improve T. urticae suppression. Intervals of 6 days between B. bassiana conidia application and N. californicus release, under both laboratory and greenhouse conditions, substantially reduced the negative effects of the fungus on the predatory mite. These findings indicate that the combined use of these biological control agents requires a well-defined sequential application strategy to maximize T. urticae suppression by the predatory mite.

Population growth and predation efficiency of three phytoseiid species fed Panonychus ulmi in Egypt

The European red mite, Panonychus ulmi (Koch), is one of the most serious pests affecting apple orchards globally, with increasing cases of resistance to conventional chemical compounds. Despite its importance, little is known about the potential of the locally Egyptian predatory mites as biological control agents against this pest. Therefore, this study presented the first comparative evaluation of the life table parameters and predation efficiency of three predatory species; Typhlodromus athiasae Porath and Swirski, Cydnoseius negevi (Swirski and Amitai), and Neoseiulus barkeri (Hughes), to identify the most efficient bio-agents for P. ulmi in the Egyptian apple orchards. This assessment was conducted using the most recent updated versions of TWOSEX-MSChart and CONSUME-MSChart computer software. Typhlodromus athiasae recorded the shortest pre-adult developmental time (♀= 6.87 and ♂= 5.38 days) compared to the other tested species at 27 ± 2 °C and 70 ± 5% RH. It also recorded the highest total fecundity rate (46.13 eggs/female), net reproduction rate (R0) (34.05 offspring/individual), intrinsic rate of increase (r) (0.209 day-1), finite rate of increase (λ) (1.23 day−1), growth reproduction rate (GRR) (38.27 offspring/individual), and the shortest generation time (T) (16.92 days). With respect to predation performance, T. athiasae achieved the highest net predation rate (C0) (573.60 prey/individual), whereas, C. negevi presented a higher finite predation rate (ω) (31.21 day-1), stable predation rate (ψ) (26.45 preys/predator), and slightly equivalent transformation rate (Qp) comparable to T. athiasae. Overall, N. barkeri displayed the weakest performance across all parameters. Correspondingly, the results demonstrated that T. athiasae and C. negevi are promising candidates for P. ulmi biological control in Egyptian apple orchards.

Stage-specific predation and functional response of Orius insidiosus (Hemiptera: Anthocoridae) toward Diaphorina citri (Hemiptera: Psyllidae) and differential toxicity of formulated pesticide mixtures.

Effect of Biological Agents in the Management of Phytophagous Mites in Strawberry (Fragaria × ananassa)

The occurrence of phytophagous mites in strawberry crops represents one of the main phytosanitary challenges of the culture, due to the high reproductive capacity and rapid dispersal of these pests. In this context, the present study evaluates the effect of different control strategies in the management of Tetranychus urticae (two-spotted spider mite) and Tetranychus ludeni (red spider mite) in a commercial strawberry crop. The experiment was conducted in a randomized block design with five treatments: Chromobacterium subtsugae, Pseudomonas fluorescens + Pseudomonas chlororaphis, Azadirachta indica, abamectin, and a control. Evaluations were performed weekly for six weeks by monitoring the mite population, number of infested leaflets, presence of eggs, leaf bronzing, web formation, and production of commercial and non-commercial fruits. At the end of the experiment, sampling of predatory mites was also conducted. The treatments based on A. indica and C. subtsugae showed lower average infestations of T. urticae and lower levels of visual damage to the plants. For T. ludeni and the variables related to fruit production, no significant differences were observed among the treatments. The results indicate that A. indica and C. subtsugae have potential for the sustainable management of the two-spotted spider mite in commercial strawberry cultivation.