Sustainable Management of Fall Armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae) in Maize Cultivation of Sri Lanka Through Local Natural Enemies

The fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) was first reported in Sri Lanka in 2018/19 Maha and caused a considerable foliage damage to the maize crop. A sustainable, ecologically, and economically viable, long-term solution adaptable to local conditions was sought to overcome the situation. Investigations were carried out to identify natural enemies and their potential for use in FAW management through their conservation and introductive/augmentative release comparing with conventional practices. An island-wide survey revealed that eight species of parasitoids and eleven species of insect predators, one species of frog and five species of birds were actively involved in suppressing of FAW population in maize crop in Sri Lanka. One Hymenoptera egg parasitoid, Telenomus remus which showed 80% parasitism and two unidentified species of Dipteran larval parasitoids, together showing 80% parasitism, belonging to Lonchaedae and Chloropidae were identified as the most prominent parasitoids of FAW. Several species of lady beetles and spiders, Staphilinid beetles, and ants were among the main predators of FAW. Farmer field demonstrations indicated that FAW damage of small scale maize cultivations (< 2 ha) could be successfully managed more profitably by implementing CBM without application of synthetic pesticides when compared with the practice of pesticide application. The main components of the proposed Community Biodiversity Management (CBM) practices include conservation of natural vegetation within the system, regular field scouting, supplementary introduction of egg parasitoid, T. remus, and application of a neem-based botanical insecticide only on early detected hotspots of FAW.