A survey of nematodes associated with native and introduced species of terrestrial slugs was conducted in the Western Cape Province of South Africa, in order to gather new data regarding diversity and distribution. A total of 521 terrestrial slugs were collected from 35 localities throughout the Western Cape. All slugs were dissected and examined for the presence of internal nematodes. Extracted nematodes were identified using a combination of molecular (18S rRNA gene sequencing) and morphological techniques. Nematodes were found parasitizing slugs at 14 of the 35 sites examined, amounting to 40% of sample sites. Of all slugs, 6% were infected with nematodes. A total of seven species of nematode were identified in the province, includingAgfa flexilis,Angiostomasp.,Phasmarhabditissp. SA1,Phasmarhabditissp. SA2,Caenorhabditis elegans,Panagrolaimussp. andRhabditissp. Of these species, four were thought to be parasitic to slugs (A. flexilis, Angiostomasp.,Phasmarhabditissp. SA1 andPhasmarhabditissp. SA2), as opposed to forming necromenic or phoretic associations. Three new species of slug-parasitic nematode were identified during this study (Angiostomasp.,Phasmarhabditissp. SA1 andPhasmarhabditissp. SA2).
Terrestrial molluscs (Mollusca: Gastropoda) are important economic pests worldwide, causing extensive damage to a variety of crop types, and posing a health risk to both humans and wildlife. Current knowledge indicates that there are eight nematode families that associate with molluscs as definitive hosts, including Agfidae, Alaninematidae, Alloionematidae, Angiostomatidae, Cosmocercidae, Diplogastridae, Mermithidae and Rhabditidae. To date,Phasmarhabditis hermaphrodita(Schneider, 1859) Andrássy, 1983 (Rhabditida: Rhabditidae) is the only nematode that has been developed as a biological molluscicide. The nematode, which was commercially released in 1994 by MicroBio Ltd, Littlehampton, UK (formally Becker Underwood, now BASF) under the tradename Nemaslug®, is now sold in 15 different European countries. This paper reviews nematodes isolated from molluscs, with specially detailed information on the life cycle, host range, commercialization, natural distribution, mass production and field application ofP. hermaphrodita.
A survey of nematodes associated with terrestrial slugs was conducted for the first time in Norway. A total of 611 terrestrial slugs were collected from 32 sample sites. Slugs were identified by means of morphological examination, dissection of genitalia and molecular analysis using mitochondrial DNA. Twelve slug species were identified, representing four different slug families. Internal nematodes were identified by means of morphological analysis and the sequencing of the 18S rRNA gene. Of the sample sites studied, 62.5% were found to be positive for nematode parasites, with 18.7% of all slugs discovered being infected. Five nematode species were identified in this study:Alloionema appendiculatum,Agfa flexilis,Angiostoma limacis,Angiostomasp. andPhasmarhabditis hermaphrodita.Of these species, only one nematode was previously undescribed (Angiostomasp.). This is the first record of the presence ofA. appendiculatum,A. flexilis andA. limacisin Norway.