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Succinea snails are considered to be invasive and pestiferous gastropods to those in the floricultural industry. Their small size makes them difficult to locate within large plant shipments, and their presence on decorative plants can constitute for an entire shipment to be rejected for sale and distribution. Research performed on Succinea snails is limited, especially in terms of effective mitigation strategies. The nematode Phasmarhabditis hermaphrodita is a biological control agent used on pestiferous gastropods throughout some European nations. Here, three strains of Phasmarhabditis from the United States (P. hermaphrodita, P. californica, and P. papillosa) were assessed as biological control agents against Succinea snails in controlled laboratory conditions, along with the molluscicide Sluggo Plus® as a control. All species of Phasmarhabditis applied at 30 IJs/cm2 caused significant mortality compared to the non-treated control and treatment with Sluggo Plus®. P. californica caused 100% mortality 6 days after exposure, while P. hermaphrodita and P. papillosa caused the same mortality rate 7 days after exposure. The molluscicide was unable to cause significant mortality compared to the non-treated control. Additional research with US Phasmarhabditis strains, including their non-target effects and distribution may lead to their being a viable option for biological control against Succinea snails. [ABSTRACT FROM AUTHOR]

The grey field slug, Deroceras reticulatum, is an agricultural pest causing damage to a wide variety of crops each year. The nematode Phasmarhabditis hermaphrodita has been shown to effectively kill this slug in field-simulated conditions, leading to its widespread use as a biological control agent in Europe. However, recently discovered isolates of Phasmarhabditis from California have not been tested in a field-simulated environment. The lethality of three local isolates of Phasmarhabditis (P. hermaphrodita, P. californica, & P. papillosa) as well as the molluscicide Sluggo Plus® was assessed on D. reticulatum in a lath house. Remaining leaf area on Canna lilies and slug mortality were recorded after 3 weeks of exposure to treatments. Local isolates efficiently killed D. reticulatum and protection from leaf damage was attained by treatment with P. papillosa. Further experimentation is required to assess plant protection afforded by Phasmarhabditis as plants in some trials may have been in poor health. The three tested Phasmarhabditis isolates are reasonable candidates for biological control within the United States but additional information, particularly on the lethality to non-target gastropods, is needed before an informed decision on their use can be made. [ABSTRACT FROM AUTHOR]