194 Accepted by R. Carreno: 4 Jul. 2017; published: 28 Aug. 2017 ZOOTAXA ISSN 1175-5326 (print edition) ISSN 1175-5334 (online edition) Copyright © 2017 Magnolia Press Zootaxa 4312 (1): 194–200 http://www.mapress.com/j/zt/ Article https://doi.org/10.11646/zootaxa.4312.1.12 http://zoobank.org/urn:lsid:zoobank.org:pub:3B9AED6F-136B-48A3-9A7A-292E9B744B75 Nematodes associated with terrestrial slugs from canola fields and ornamental nurseries in South Africa ANNIKA PIETERSE 1 , ANTOINETTE P. MALAN 1 , LAURA M. KRUITBOS 2 , WILLEM SIRGEL 3 & JENNA L. ROSS 1,2,4 1 Department of Conservation Ecology and Entomology, Faculty of Agrisciences, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa 2 Institute of Biological and Environmental Sciences, University of Aberdeen, AB24 3UU, UK 3 Department of Botany and Zoology, Stellenbosch University, Private Bag XI, Matieland 7602, South Africa 4 Corresponding author. E-mail: jenna.ross@abdn.ac.uk Abstract A survey of nematodes that use terrestrial slugs as definitive hosts, was conducted in canola fields and ornamental nurs- eries located in the Western Cape province of South Africa. A total of 3290 slugs were collected from 22 different sites. On the identification of the slugs, they were vivisected and examined for internal nematodes. After identifying the nema- todes found, on the basis of their morphological characteristics, their identity was confirmed using molecular sequence data for the internal transcribed spacer (ITS-1, 5.8S, ITS-2), D2-D3 expansion segments of the large subunit (LSU or 28S) and small subunit (SSU or 18S) ribosomal DNA. Of the 22 sites investigated, 13 had nematodes present, with 8 % of the slugs being found to be infected with nematodes. Seven nematode species were confirmed, including Agfa flexilis, An- giostoma margaretae, Angiostoma sp. (SA1), Caenorhabditis elegans, mermithid sp. (SA1), Phasmarhabditis sp. (SA3) and Phasmarhabditis sp. (SA4). In addition, several Angiostoma spp. were also isolated, but could only be identified to genus level due to limited material. Of the seven confirmed species, four were previously undescribed. This is the first record of A. margaretae associating with Deroceras panormitanum, Deroceras reticulatum, Lehmannia valentiana and Oopelta polypunctata. Also, this is the first time that a mermithid has been found associating with molluscs in South Af- rica. Key words: Agfa, Angiostoma, Molluscs, Nematodes, Parasites, Phasmarhabditis Introduction Surveys of nematodes that use terrestrial slugs as definitive hosts have been conducted on all continents, with the exception of Antarctica (Ross et al., 2016). Current knowledge indicates that seven nematode families, consisting of Agfidae, Alloionematidae, Angiostomatidae, Cosmocercidae, Diplogastridae, Mermithidae, and Rhabditidae, associate with terrestrial slugs as definitive hosts. However, to date, the only nematode to be commercially developed as a biological molluscicide is Phasmarhabditis hermaphrodita (Schneider) Andrássy. Phasmarhabditis hermaphrodita is capable of infecting slug species from the families Agriolimacidae, Arionidae, Milacidae, Limacidae, and Vagnulidae (Wilson et al., 1993a; Iglesias & Speiser, 2001; Speiser et al., 2001; Grewal et al., 2003; Rae et al., 2008). The infectious nematode larvae enter slugs through natural openings, and then once inside, inhibit mollusc feeding, with death following between 4-21 days after nematode infection (Tan & Grewal, 2001). The nematode, which was made commercially available by BASF (formally MicroBio Ltd and Becker Underwood) in 1994, under the trade name Nemaslug®, is currently sold in 15 different European countries (G. Martin, personal communication, March 24, 2015). To date, the above-mentioned product cannot be commercially sold in South Africa, due to existing legislation, in terms of which P. hermaphrodita is seen as an exotic species (Amendment of Act 18 of 1989, enforceable under the Agricultural Pest Act 36 of 1947). In 2012, a study was published on nematodes associated with terrestrial slugs