First insights into the genetic diversity of Spodoptera spp. (Lepidoptera: Noctuidae) affecting vegetable crops in Jamaica

Abstract

Abstract Spodoptera spp. (Lepidoptera: Noctuidae) are economically important insect pests of cereal and vegetable crops in Tropical and Subtropical regions of the Americas, but little is known of their distribution and diversity in countries of the Caribbean, in particular, Jamaica. In this study, larvae collected from hosts in the three major vegetable producing regions of Jamaica were characterized based on morphological characters and mitochondrial cytochrome c oxidase I (COI) sequence data. Three species were identified; S. exigua, S. latisfascia and S. frugiperda. All three species were prevalent on bunching onions (Allium fistulosum); while bell pepper (Capsicum annum) and corn (Zea mays) were also hosts for S. exigua and S. frugiperda, respectively. Species clades at 99% confidence were obtained in phylogenetic analyses with Jamaican COI sequences and those from different geographical locations. Separate clustering occurred with native S. latisfascia and invasive S. exigua populations of the Americas. S. frugiperda corn and rice strain groupings that were closely related to native accessions of the Americas and invasives in Africa and Asia, including populations with recorded insecticide resistance, were distinguished. Based on this sampling, the Jamaican populations are consistent with those previously reported in the Americas and elsewhere. Low intraspecific genetic distances of ≤ 0.6% were obtained with the three species and apart from two exceptions, interspecific distances ranged from zero to 1.4%. The results provide new information about the population dynamics of Spodoptera species affecting vegetable crops in Jamaica and establish a baseline for further studies.