Efficacy of pitfall trapping, Winkler and Berlese extraction methods for measuring ground-dwelling arthropods in moist-deciduous forests in the Western Ghats
Litter Entomology Research Unit, Post Graduate & Research Department of Zoology, St. Joseph’s College, Devagiri, Calicut, Kerala, India 673008
Abstract
The present study provides data to decide on the most appropriate method for sampling of ground-dwelling arthropods measured in a moist-deciduous forest in the Western Ghats in South India. The abundance of ground-dwelling arthropods was compared among large numbers of samples obtained using pitfall trapping, Berlese and Winkler extraction methods. Highest abundance and frequency of most of the represented taxa indicated pitfall trapping as the ideal method for sampling of ground-dwelling arthropods. However, with possible bias towards surface-active taxa, pitfall-trapping data is inappropriate for quantitative studies, and Berlese extraction is the better alternative. Berlese extraction is the better method for quantitative measurements than the other two methods, whereas pitfall trapping would be appropriate for qualitative measurements. A comparison of the Berlese and Winkler extraction data shows that in a quantitative multigroup approach, Winkler extraction was inferior to Berlese extraction because the total number of arthropods caught was the lowest; and many of the taxa that were caught from an identical sample via Berlese extraction method were not caught. Significantly a greater frequency and higher abundance of arthropods belonging to Orthoptera, Blattaria, and Diptera occurred in pitfall-trapped samples and Psocoptera and Acariformes in Berlese-extracted samples than that were obtained in the other two methods, indicating that both methods are useful, one complementing the other, eliminating a chance for possible under-representation of taxa in quantitative studies.
Keywords: forest floor arthropods, soil-litter arthropods, quantitative and qualitative sampling, Acariformes, Araneae, Blattaria, Chalcidae, Chilopoda, Coleoptera, Dermaptera, Diplopoda, Diptera, Formicidae, Hemiptera, Homoptera, Isopoda, Isoptera, Larva, Lepidoptera, Mantoidea, Orthoptera, Hymenoptera, Parasitiformes, Phasmida, Pseudoscorpionida, Psocoptera, Thysanoptera
Correspondence:
asabukthomas@gmail.com
Associate Editor: T.X. Liu was editor of this paper.
Received: 11 July 2008 | Accepted: 15 January 2009 | Published: 8 July 2010
Copyright: This is an open access paper. We use the Creative Commons Attribution 3.0 license that permits unrestricted use, provided that the paper is properly attributed.
ISSN: 1536-2442 | Volume 10, Number 98
Sabu TK, Shiju RT. 2010. Efficacy of pitfall trapping, Winkler and Berlese extraction methods for measuring ground-dwelling arthropods in moist-deciduous forests in the Western Ghats. Journal of Insect Science 10:98, available online: insectscience.org/10.98
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