Fungi as Control Bioagents Against the Terrestrial Snail, Eobania vermiculata

The molluscicidal potencies of the recommended fungal isolates; Metarhizium anisopliae, Paecilomyces lilacinus, Trichoderma harzianum and Verticillium albo-atrum against juveniles (two and four months old) age and adults of Eobania vermiculata (Müller, 1774) (Gastropoda, Stylommatophora, Helicidae) snail was investigated. Three tested concentrations of 2 × 10⁵, 4 × 10⁵ and 6 × 10⁵ spores/ml from each fungal isolate were tested against the snail ages under the laboratory conditions. The two most effective fungal isolates that achieved the highest molluscicidal effect against adult snails in the laboratory were selected to be applied against the adult individuals in the field. The results indicated that V. albo-atrum and T. harzianum were the most potent fungi against all ages of snails in the laboratory. They recorded 90 & 83.33% and 86.66 & 76.66% mortality for juveniles two and four months old at the highest concentration of 6 × 10⁵ spores/ml after one month of the infection, respectively. After this period and at the tested concentration, both fungal isolates caused 63.33 and 60% mortality in adult individuals, respectively. On the contrary, P. lilacinus had the lowest molluscicidal activity against all stages of the snail. Under the field conditions, the molluscicidal influence of V. albo-atrum against snails was greater than that of T. harzianum as they achieved 58.06 and 55.10% reduction of snails at the highest concentration of 6 × 10⁵ spores/ml after a month of application, respectively. These results indicate that the fungal isolates in this study especially V. albo-atrum and T. harzianum have a high potential molluscicidal impact on all developmental stages of E. vermiculata snails making them promising fungi that can be commercially manufactured and used as future safe biopesticides for control this harmful snail.