Nematodes associated with terrestrial slugs in the Edmonton region of Alberta, Canada

Abstract

A survey of nematodes associated with terrestrial slugs was conducted in residential gardens, nurseries, greenhouses and agricultural sites located in and around Edmonton, Alberta, Canada. A total of 2406 slugs were collected from 82 sites. Slugs were decapitated and cadavers were incubated for two weeks, with emerging nematodes removed and processed for identification. Nematodes were identified using molecular sequence data for the 18S ribosomal DNA. Nematodes were recovered from 20 of the 82 sites surveyed, with 24.4% of the slugs infected with nematodes. A total of seven nematodes were identified to species level, including Caenorhabditis elegans, Panagrolaimus papillosus, Pellioditis typica, Pelodera pseudoteres, Rhabditella axei, Rhabditoides inermiformis and Phasmarhabditis californica. An additional four specimens were identified to genus level, including Oscheius sp. (9), Pristionchus sp., Rhabditis sp. and Rhabditophanes sp. (1). The two most common nematode species were C. elegans and P. pseudoteres. The facultative parasite, P. californica, was recovered from a single Arion rufus specimen, collected from a seasonal nursery. To our knowledge, this study represents the first survey of slug-associated nematodes in Canada.

Distribution of Phasmarhabditis (Nematode: Rhabditidae) and Their Gastropod Hosts in California Plant Nurseries and Garden Centers

“…Such surveys have the potential to identify previously unknown nematode-gastropod relationships or identify new species of nematodes with biocontrol potential. These types of discoveries have been seen in other surveys performed across the globe ( Ross et al, 2012 ; Tandingan De Ley et al, 2014 ; Mc Donnell et al, 2018a ; Brophy et al, 2020 ). In this survey, we aimed to determine the presence and distribution of Phasmarhabditis nematodes and the diversity of gastropods in nurseries and garden centers throughout California.…”

“…These nematodes are not uncommon in gastropods, and though the interaction between C. remanei and gastropods has not been thoroughly explored, C. elegans is thought to have a phoretic association with gastropods ( Caswell-Chen et al, 2005 ; Ross et al, 2012 ; Petersen et al, 2015 ; Rae, 2017 ; Sudhaus, 2018 ). C. elegans is also known to have phoretic associations with some species of earthworms and arthropods ( Kiontke and Sudhause, 2006 ; Brophy et al, 2020 ). Other interesting nematode species were also discovered during the California surveys including Cosmocercoides tonkinensis , which is not commonly associated with gastropod hosts ( Supplementary Table 1 and Tables 3 , 4 ; Sudhaus, 2018 ).…”

Pestiferous slugs and their associated nematodes in agricultural fields, greenhouses, and nurseries in Alberta, Canada

“…Slugs were collected from field margins and the adjacent vegetation stripes of three major agricultural sites in Alberta (Figure 1) from August to September 2021, a period corresponding to peak slug activity (Brophy et al 2020b). In addition, ten commercial greenhouses and nurseries in Alberta were surveyed from June to September 2021 (Figure 1).…”

“…Canada had no previous record of Phasmarhabditis in the region until a recent discovery of a Canadian strain of P. californica, which was reported from a single slug ( Arion rufus ) collected from the exterior grounds of a local nursery in Edmonton (Brophy et al 2020a; Brophy et al 2020b). However, isolating a Canadian strain of P. californica from a single slug specimen is not sufficient evidence to confirm that the nematode is established locally.…”

Influence of aromatic substances on locomotor activity of Deroceras agreste slugs

“…The most important of them is the use of biological agents against pests. To regulate the number of D. agreste, there are often used protozoans Tetrahymena rostrata (Haites et al, 2021), nematodes of Phasmarhabditis genus (Brophy et al, 2020;McDonnell et al, 2020):…”