Distribution and diversity of entomopathogenic nematodes (Steinernematidae and Heterorhabditidae) in a South African nature reserve

Koedoe - African Protected Area Conservation and Science

 
 
Field Value
 
Title Distribution and diversity of entomopathogenic nematodes (Steinernematidae and Heterorhabditidae) in a South African nature reserve
 
Creator Nthenga, Isiah Knoetze, Rinus Malan, Antoinette P.
 
Subject Ecology distribution; fynbos; JS Marais Nature Reserve; natural habitat; natural veld
Description Entomopathogenic nematodes (EPNs) are microscopic roundworms that are found in soil worldwide. They deliver an important ecosystem service through preventing natural flares in insect reproduction by means of utilising the soil stages of insects as a food source and by acting as natural biocontrol agents. A survey of EPNs was conducted in the JS Marais Nature Reserve, Stellenbosch, in the Western Cape province of South Africa. Soil samples were baited with the larvae of three susceptible hosts, codling moth (Cydia pomonella), wax moth (Galleria mellonella) and mealworm (Tenebrio molitor) to determine the presence of EPN. Of the 76 soil samples collected across the reserve, 39 were found to be positive for the presence of EPN (51.32%). Among the positive samples, 87% contained Steinernema isolates, 8% contained Heterorhabditis and 5% contained the Oscheius sp. Morphological and molecular studies were performed to characterise the isolates to species level. The Steinernema species were identified as Steinernema khoisanae in 34 samples, and as Steinernema nguyeni in five samples. The only species of Heterorhabditis found was H. safricana, which was identified from three samples. An unknown Oscheius sp. was found in two samples. The reserve’s population of S. khoisanae showed interesting inter-individual variation (93%) early in the internal transcribe spacer (ITS) region, leading to short single-usable sequences, which, in most cases, included only the ITS1 or ITS2 region. However, using the D2D3 confirmed their identity as S. khoisanae, with such occurring in all areas and soil types of the reserve.Conservation implications: The undisturbed alluvial fynbos and renosterveld of the JS Marais Nature Reserve showed high EPN abundance and diversity in stark contrast to the agro-ecosystems present in the Cape floristic region. This finding, on a micro level, should be conserved for future bioprospecting in the fynbos for EPNs with potential as biocontrol agents.
 
Publisher AOSIS Publishing
 
Contributor Flemish Inter-University Council – University Development Cooperation (VLIR-UOS) the Technology and Human Resources for Industry Programme (THRIP)
Date 2021-11-22
 
Type info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion — Survey
Format text/html application/epub+zip text/xml application/pdf
Identifier 10.4102/koedoe.v63i1.1661
 
Source Koedoe; Vol 63, No 1 (2021); 7 pages 2071-0771 0075-6458
 
Language eng
 
Relation
The following web links (URLs) may trigger a file download or direct you to an alternative webpage to gain access to a publication file format of the published article:

https://koedoe.co.za/index.php/koedoe/article/view/1661/2889 https://koedoe.co.za/index.php/koedoe/article/view/1661/2890 https://koedoe.co.za/index.php/koedoe/article/view/1661/2891 https://koedoe.co.za/index.php/koedoe/article/view/1661/2892
 
Coverage South Africa, Western Cape n/a Abundance; species richness
Rights Copyright (c) 2021 Isiah Nthenga, Rinus Knoetze, Antoinette Paula Malan https://creativecommons.org/licenses/by/4.0
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