Concomitancy of Entomophilous and Soil Transmitted Nematodes in Selected Insects

Aim: To determine the occurrence of entomophilous and soil transmitted nematodes of three insect species; Zonocerus variegatus, Gryllotalpa orientalis and Mantis religiosa in Obio Akpor, Local Government Area of Rivers State, Nigeria.

Methodology: The insect samples were collected with entomological sweep net as described by Colwell [1] and pitfall traps as described by Davies [2]. Insect samples were dissected using Stubbins’ method [3] while nematodes in the insects were isolated and identified according to Cheesborough, (2005).

Results: Two hundred and forty-eight (248) insect specimens comprising; Z. variegatus 193 (77.8%), G. orientalis 42(16.9%) and Mantis religiosa 13(5.2%) were collected from designated ecological settings based on availability and trapping efficiency. Out of the 248 insects sampled; 145 (58.5%) were infected with three genera of nematodes comprising; Ascaris lumbricoides; 17 (7.5%), Mermis Spp., 148 (65.5%) and Trilabiatus lignicolus 61(27.0%). Mermis Spp., an entomophilous nematode occurred in Z. variegatus and Mantis religiosa due to host specific factors. Nematode occurrence in the host did not indicate sex relationship (P>0.05) however, hosts age influenced parasite occurrence as older insects harbored more parasites (P<0.05). Trilabiatus lignicolus; a free-living soil nematode and A. lumbricoides; a soil transmitted helminthes found in the guts of Z. variegatus and G orientalis was attributed to the feeding habits of the insects.

Conclusion: The study indicated that Z. variegatus and G. orientalis as veritable vectors of soil transmitted nematodes while Z. variegatus and Mantis religiose are suitable host of the entomophilous nematode Mermis Spp.