Evaluation of Native Entomopathogenic Nematode Isolates for the Management of Selected Insect Pests in Nigeria

Document Type : Original Article

Authors

1 Dept. Crop Protection Environmental Biology, University of Ibadan, Ibadan, Nigeria

2 Dept. of Crop Protection and Env. Biology University of Ibadan

Abstract

Native entomopathogenic nematodes (EPNs) were evaluated for the management of three selected pests, Sesamia calamistis, Spodoptera frugiperda and Rhynchophorus ferrugineus in laboratory bioassays. The EPNs were isolated from soils from various locations within Ibadan, Nigeria using the greater wax moth (Galleria mellonella) as insect bait. A two-factor laboratory experimental assay was laid out in a completely randomized design and replicated three times. The EPN suspension was applied on insect larvae with distilled water as control. Number of days to mortality, percentage mortality of insect larvae, and total EPN population of infective juveniles (IJs) recovered from larval cadavers were assessed and reproductive factor (RF) determined.  Data were analyzed using analysis of variance, and means were separated using Tukey’s Studentized Range Test at P<0.05. The number of days to mortality for inoculated larvae of S. calamistis, S. frugiperda, R. ferrugineus and G. mellonella were 6.43, 3.57, 8.80 and 6.20, respectively. The EPN population achieved percentage mortality of 82.0%, 54.0%, 60.0% and 84.0%, respectively for G. mellonella, S. calamistis, S. frugiperda and R. ferrugineus larvae respectively. Mean numbers of EPN IJs recovered from cadaver was in the order; R ferrugineus (9,407.0), >G. mellonella (5075.08), >S. frugiperda (3957.23), >S. calamistis (742.31). From the results, EPN had the greatest fecundity in G. mellonella and R. ferrugineus showing higher ability to be recycled. This study reveals the potential of native EPNs as a biocontrol agent of insect pests and emphasizes the need for a more environment-friendly and sustainable approach to insect pest management.

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