IOSR Journal of Agriculture and Veterinary Science (IOSR-JAVS) e-ISSN: 2319-2380, p-ISSN: 2319-2372. Volume 11, Issue 6 Ver. II (June 2018), PP 48-53 www.iosrjournals.org DOI: 10.9790/2380-1106024853 www.iosrjournals.org 48 | Page Potential of Entomopathogenic Nematodes for the Management of Sesamia calamistis in Nigeria Claudius-Cole, A. O. Department of Crop Protection and Environmental Biology, University of Ibadan, Nigeria Corresponding Author: Claudius-Cole, A. O. Abstract: The management of agricultural insect pests with entomopathogenic nematodes (EPNs) is recognized internationally as a sustainable and environmentally friendly method of management. This study aimed at determining the efficacy of indigenous EPNs on the management of Sesamia calamistis, the stem borer of maize. Soil samples were collected within 5 × 5 m quadrants (r = 3) from seven forests and three cultivated locations within Ibadan. In the laboratory, 200 cm 3 from each quadrant per location were bulked to form a composite per location and used for the trial. The composite soil was properly mixed and moistened with water, and 500 cm 3 was measured into transparent plastic containers. Ten S. calamistis larvae were placed on the soil surface and the containers were inverted and placed in the dark. Larval mortality was recorded every 48 hrs for 10 days. Dead larvae were counted, removed and assessed for nematode infection. Descriptive statistics and ANOVA were performed on the data. Nematodes in the genus Heterorhabdidtis were identified from insect cadavers. Laval mortalities were 4- 57% from soils where they were found. Nematode populations recovered per cadaver ranged from 250 from soil of UI botanical garden to 3,350 from CRIN plantation. Nematode infection on the larvae from naturally infested soil indicates that a more targeted application from quantified laboratory cultures will likely provide good management of the stem borer species. Keywords: biological control, maize, Heterorhabdidtis, Steinernema, stemborer --------------------------------------------------------------------------------------------------------------------------------------- Date of Submission: 16-06-2018 Date of acceptance: 02-07-2018 --------------------------------------------------------------------------------------------------------------------------------------- I. Introduction Nematode parasites of insects have been known since the 17th century (1), but it was only in the 1930’s that serious consideration was given to using nematodes to control an insect pest. Like other nematodes, entomopathogenic nematodes are soft bodied, non-segmented roundworms that are obligate or facultative parasites of insects. They occur naturally in soil environments and locate their host in response to various cues (2). EPNs have been found all over the world in a range of ecologically diverse habitats. The most commonly studied entomopathogenic nematodes are those that can be used in the biological control of harmful insects, the members of Heterorhabditidae and Steinernematidae (3). Species in these two families have been effectively used as biological insecticides in pest management programs (4) for insects in Lepidoptera, Coleoptera, Diptera and Hemiptera (2) In Nigeria, some basic research have been conducted regarding EPNs mainly in the surveying for the presence of the nematodes. Heterorhabditis bacteriophora and Steinernema feltiae were the two EPNs identified from 6.5% of the positive samples taken from three states in north central Nigeria (4). In another study by Eche et al. (5), conducted in two north central states of Nigeria, 2% of the samples were positive for EPNs from which Heterorhabditis sp. H. indica, and H. bacteriophora were identified. Depending on the environmental niche, EPNs have two main strategies for infecting their hosts. Those with a mobile foraging strategy (cruisers and intermediate foraging strategies) could be considered for use in above-ground habitats (foliar, epigeal habitats). Those with a sit and wait foraging strategy (ambushers) will be most effective in cryptic and soil surface habitats (6). The use of entomopathogentic nematodes is particularly attractive as a biological control method because they can tolerate and are compatible with may synthetic insecticides unlike most parasitoids. Negrisoli et al. (7) demonstrated that 12 out of the 18 insecticides approved for the management of the fall army worm in Brazil were compatible with three species of EPNs. The Stem borer Sesamia calamistis Hampson (Lepidoptera: Noctuidae) is widely distributed in Nigeria where it causes damage to maize crops (8) (9). The characteristic damage of tunneled internodes and dead heart can result to yield loss of between 36-100% depending on the level of infestation (10); (11). The various strategies for managing the pest include biological control options such as entomopathogenic nematodes (12) (13). In this study, a preliminary assessment was conducted with the purpose of detecting EPNs in soils from the south west of Nigeria and evaluating mortality of S. calamistis in the collected samples.