INCIDENCE, MORPHOLOGICAL DESCRIPTION, DNA BARCODING AND PHYLOGENETIC ANALYSIS OF ARMYWORM, LEUCANIA ALBISTIGMA (LEPIDOPTERA: NOCTUIDAE) ON MAIZE FROM INDIA

First record of Leucania albistigma from India

Abstract

In India, armyworms and cutworms are pests of crops and assume serious pest status occasionally causing significant damage to agricultural crops. Following distress calls from maize growers, survey was undertaken to known the incidence and taxonomic identity of the pest which occurred in outbreak form with severe defoliation on maize over 1000 hectares in Shivamogga district of Karnataka.  In the adjoining maize fields, infestation was also noticed on sorghum and rice. Through morphological characters including genitalia and DNA barcoding study, we report the taxonomic identity of Leucania albistigma Moore, 1881 (Lepidoptera: Noctuidae) as armyworm for the first time from India. As the taxonomic information of this species was scanty, redescription of all the stages was provided with images. DNA barcoding and phylogenetic analysis revealed that species of the genera Leucania has a close relationship with the species of Mythimna.  Further, using quadrat method, spatial distribution of larvae in fields with severe outbreak was recorded based on the larval counts on the plants and in soil. Surprisingly, spatial distribution indices analysed indicated uniform distribution in soil but aggregated distribution on maize plants. The selected insecticides were evaluated in field targeting larvae with spray and with poison bait in randomised block design. Treatments with poison bait outperformed other spray formulations, indicating larval behaviour could be exploited for its successful management. As different species of armyworms are polyphagous and occur frequently in Indian subcontinent, the taxonomic, ecological and management studies undertaken forms a basis for future monitoring of species identity and outbreaks on cereal crops.