Response of grey slug to entomopathogenic nematodes

Abstract

Biological control using entomopathogenic nematodes (EPNs) is known as an ecofriendly strategy in integrated pest management. The terrestrial slug Parmacella ibera is a major pest of vegetables and citrus trees in north of Iran. The heavy costs and environmental concerns of synthetic molluscicides led the study to use EPNs, against the slug P. ibera.The present study was arranged to evaluate and compare the performance of EPNs, Steinernema feltiae, S. carpocapsae and Heterorhabditis bacteriophora on P. ibera population (mortality rate) and the feeding rate in vitro, and also its damage (seedlings establishment rate) in vitro.Phasmarhabditis hermaphrodita, as a slug parasite nematode, and also the metaldehyde, as a molluscicide, were used as positive controls. The results of the study showed that the highest mortality rate (%) and the seedlings establishment rate (%) of the slug population were observed in S. carpocapsae, S. feltiae and H. bacteriophora treatments, respectively.The feeding rate (%) of the slug declined in the treatments with H. bacteriophora, S. feltiae and S. carpocapsae, respectively. The mortality rate of the pest was enhanced by extending the exposure time and increasing levels of the nematodes. Therefore, it can be concluded that the EPNs S. carpocapsae, S. feltiae and H. bacteriophora are able to control the slug P. ibera population.

Morph‐dependent nematode infection and its association with host movement in the land snail Cepaea nemoralis (Mollusca, Gastropoda)

“…Food intake was influenced by nematode infection: highly parasitized snails ate less (Table 2). Feeding reduction in nematode‐infected individuals has been documented in other terrestrial molluscs (Antzée‐Hyllseth et al., 2020; Saeedizadeh & Niasti, 2020) and is an indication that parasite infection is indeed costly for snails even if they are non‐lethal, at least in adults (Grannell et al., 2021; Williams & Rae, 2016; Wilson et al., 2000). By contrast, trematode infection had no effect on the behaviour, including feeding behaviour (Table 2).…”

Entomopathogenic nematode-gastropod interactions

“…The study by Saeedizadeh and Niasti (2020) provided reasonable evidence that EPNs may be effective biological control agents. They used quantifiable doses over a large range, a reasonably timed assay, and measured aspects of the host biology.…”

“…However, whether the EPNs parasitized the slugs was not determined. Saeedizadeh and Niasti (2020) did not stage the nematodes after infection. Koch’s postulates were not met, and no aspect of nematode biology was measured.…”

“…The most recent study of EPN-gastropod interactions was by Saeedizadeh and Niasti (2020) . This paper explored the response of Parmacella ibera to the EPNs S. feltiae , S. carpocapsae and H. bacteriophora .…”

Morph-dependent nematode infection and its association with host movement in the land snail Cepaea nemoralis (Mollusca, Gastropoda)

“…Food intake was influenced by nematode infection: highly parasitized snails ate less ( Table 2 ). Feeding reduction in nematode-infected individuals has been documented in other terrestrial mollusc species (Antzée-Hyllseth et al ., 2020; Saeedizadeh & Niasti, 2020) and is an indication that parasite infection is indeed costly for snails even if they are non-lethal, at least in adults (Wilson et al ., 2000; Williams & Rae, 2016; Grannell, Cutler & Rae, 2021). By contrast, trematode infection had no effect on behaviour, including feeding behaviour ( Table 2 ).…”