The Mesostigmatid Mite Protogamasellus mica, an Effective Predator of Free-Living and Plant-Parasitic Nematodes

Graham R Stirling,David E Walter,A Marcelle Stirling

doi:10.21307/jofnem-2017-080

Graham R Stirling, David E Walter + Show 1 more

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https://doi.org/10.21307/jofnem-2017-080

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Abstract

Protogamasellus mica was extracted from a sugarcane field in Australia and cultured on bacterial-feeding nematodes. Studies with various nematodes in laboratory arenas showed that one mite and its progeny reduced nematode numbers by between 26 and 50 nematodes/day. A bacterivore (Mesorhabditis sp.), a fungivore (Aphelenchus avenae), and two plant parasites (root-knot nematode, Meloidogyne javanica and root-lesion nematode, Pratylenchus zeae) were all reduced at much the same rate despite the fact that the nematodes are quite different in size and motility and belong to different trophic groups. When sugarcane was grown in the greenhouse for 8 wk, stunt nematode (Tylenchorhynchus annulatus), a plant parasite that feeds ectoparasitically on roots, was almost eliminated from pots inoculated with the mite, and numbers of microbivores and root-lesion nematode were markedly reduced. Huge reductions in nematode populations were also observed when mites were added to microcosms containing small quantities of defaunated soil. These results show that P. mica multiplies rapidly when nematodes are available as a food source and has the capacity to play a role in regulating populations of both plant-parasitic and free-living nematodes. Future research should focus on understanding the crop and soil management practices required to enable this mite and other predatory species to thrive.

Highlights

Protogamasellus mica was extracted from a sugarcane field in Australia and cultured on bacterial-feeding nematodes
Feeding studies in laboratory arenas: Results of four similar experiments with different nematodes are presented in Table 1, and they show that the number of nematodes was markedly reduced when P. mica was present, regardless of the nematode species used as a food source
Mites were never recovered from the no mite treatment but P. mica multiplied in the vials into which it had been added

Summary

Introduction

Protogamasellus mica was extracted from a sugarcane field in Australia and cultured on bacterial-feeding nematodes. Huge reductions in nematode populations were observed when mites were added to microcosms containing small quantities of defaunated soil These results show that P. mica multiplies rapidly when nematodes are available as a food source and has the capacity to play a role in regulating populations of both plant-parasitic and free-living nematodes. Plant-parasitic nematodes have been widely studied because they damage root systems and reduce the yield of most crops (Evans et al, 1993; Luc et al, 2005), but from an ecological perspective, free-living nematodes are probably more important These nematodes feed on bacteria, fungi, and other soil organisms, and during that process, they regulate populations of their prey and increase the availability of nutrients required by plants (Ingham et al, 1985; Yeates and Wardle, 1996; Ferris et al, 1998; Chen and Ferris, 1999; Stirling, 2014). As nothing is known about the capacity of these animals to prey on nematodes in a soil environment, this study aimed to determine whether they consumed enough nematodes to play a role in regulating populations of nematode pests

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