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Slugs and snails (class Gastropoda) are the obligate intermediate hosts of the rat lungworm, Angiostrongylus cantonensis. This nematode is the causative agent of human angiostrongyliasis and the most common cause of human eosinophilic meningoencephalitis. Humans can become infected by accidental consumption of slugs or snails and possibly flatworms (or a portion of one of these animals) in fresh produce, but the slime from these animals can contain nematodes and may also constitute a disease risk. Gastropod carriers in Hawai'i include, among other species, giant African snails, veronicellid slugs, and the semi-slug Parmarion martensi. This latter species was first discovered on the island of Hawai'i in 2004 and is now common in the area where the majority of the state's documented cases of human angiostrongyliasis occurred between 2005 and 2011. This species is considered a high risk carrier of A. cantonensis because of its climbing behavior, abundance around human dwellings, and high worm burdens. One individual collected from east Hawai'i Island contained >6,800 infective third stage A. cantonensis larvae. Common and efficient control methods for slugs and snails include sanitation (eg, removal of objects that serve as hiding places) and the use of poison food baits, such as those containing metaldehyde and iron. An ironcontaining bait that is relatively safe to non-target organisms was effective in controlling semi-slugs in cage experiments, although it killed more slowly than a metaldehyde-containing bait and the majority of slugs affected did not die until 1-2 weeks following ingestion. [ABSTRACT FROM AUTHOR]

In Hawaii, Zonitoides arboreus (Say) is a serious pest of potted orchids, particularly those grown in bark- or coir-based media. This snail, which feeds preferentially on roots at or near the surface, causes the plant to become unstable within the pot which makes it unmarketable. Affected plants cannot be sold until roots have regrown. There is little published information about the control of this important pest. Our primary objective was to test commercially available and experimental molluscicides for control of Z arboreus in laboratory and greenhouse trials. Molluscicides were first tested within Petri dishes to facilitate behavioural observations related to attraction or repellency of food baits and other products added to filter paper, and mortality of snails exposed to chemicals in this manner. Promising chemicals were then tested in greenhouse trials. Chemicals tested included a wide variety of commercial products containing metaldehyde; methiocarb (a carbamate); a bait product containing iron phosphate; a coppercontaining fungicide; two extracts of neem (azadirachtin and neem oil) and an experimental extract of yucca known to repel slugs and snails. There was no evidence that snails were attracted to any of the food baits. The liquid metaldehyde products and the yucca extract caused snails to withdraw immediately into their shells and avoid contact with treated filter paper for up to 1 week. Both neem products acted as phagostimulants. Best control in greenhouse trials was obtained using a liquid formulation of metaldehyde, metaldehyde granules with inert carrier containing 7.5% active ingredient or methiocarb. [ABSTRACT FROM AUTHOR]