Management of Spodoptera frugiperda J.E. Smith Using Recycled Virus Inoculum from Larvae Treated with Baculovirus under Field Conditions

Allan Mweke; Ivan Rwomushana; Arthur Okello; Duncan Chacha; Jingfei Guo; Belinda Luke

doi:10.3390/insects14080686

Management of Spodoptera frugiperda J.E. Smith Using Recycled Virus Inoculum from Larvae Treated with Baculovirus under Field Conditions

Insects. 2023 Aug 3;14(8):686. doi: 10.3390/insects14080686.

Authors

Allan Mweke^{1

2}, Ivan Rwomushana², Arthur Okello², Duncan Chacha², Jingfei Guo³, Belinda Luke⁴

Affiliations

¹ Department of Animal Health and Production, School of Pure and Applied Sciences, Mount Kenya University, Thika P.O. Box 342-01000, Kenya.
² Centre for Agriculture and Biosciences International (CABI) Africa, Canary Bird, 673 Limuru Road, Muthaiga, Nairobi P.O. Box 633-00621, Kenya.
³ Institute of Plant Protection, Chinese Academy of Agricultural Sciences (IPP-CAAS), Beijing 100193, China.
⁴ Centre for Agriculture and Biosciences International (CABI), Bakeham Lane, Egham, Surrey TW20 9TY, UK.

Abstract

Fall armyworm (FAW) is a major pest of maize and causes huge losses. Chemical pesticides are the commonly used control strategy among farmers. The efficacy of baculoviruses against FAW has been proven; however, farmers may not be able to afford the products. The use of farmer-produced baculovirus mixtures could provide an opportunity for a nature-based solution for FAW at a low cost. This study evaluated the potential of recycled virus inoculum from FAW larvae treated with a commercial baculovirus (Littovir) for the management of FAW under laboratory and field conditions. In the laboratory, the virus from 25, 50, 75 and 100 FAW larvae caused variable mortality among FAW instars. The highest mortality (45%) among 1^st-3^rd instars was caused by Littovir followed by recycled virus inoculum from 100 FAW larvae (36%). Under field conditions, even though recycled virus inoculum did not offer adequate protection against FAW damage, the maize yield was comparable to that of commercial insecticide-treated plots and similar to that of control plots. This study has shown the potential use of recycled virus inoculum from infected larvae for the management of FAW. This would offer the farmers a sustainable and affordable option for the management of FAW as it would require the farmers to purchase the commercial baculovirus once and collect larvae from treated plots for repeat applications.

Keywords: Littovir; damage; fall armyworm; insecticides; maize; virus; yield.

Grants and funding

The study was conducted as part of CABI’s PlantwisePlus program, which is funded by the UK Foreign, Commonwealth and Development Office (FCDO), Netherlands Directorate-General for International Cooperation (DGIS), Swiss Agency for Development and Cooperation (SDC) and the European Commission (DG INTPA).