Identifying Diversity of Thrips on Lablab (Lablab purpureus): A Potential Vegetable Crop

Background: Lablab (Lablab purpureus) is a potential vegetable crop cultivated throughout India. It is a tropical and subtropical vegetable adaptive to different climatic conditions and grown in all seasons. Thrips are one of the important pests of lablab as they affect all stages of the crop and transmit plant viruses. The current study aimed at identifying the thrips diversity present in lablab as a base for monitoring and management purposes. Methods: An exploratory survey was conducted to identify the diversity of thrips on lablab in its growing areas of Coimbatore. Furthermore, continuous monitoring of the lablab crops in TNAU orchard, Coimbatore, was done to explore all the life stages of thrips species and their diversity. Morphological and molecular characterization of the collected species was done using taxonomic keys and mtCOI DNA sequencing approach. Result: Thrips palmi and Thrips tabaci were observed during the crop’s early stages before blossoming. Frankliniella schultzei is a polyphagous pest species that has been found infesting all phases of crop development, from early leaf through pod formation. During and after blooming, the four species Megalurothrips usitatus, Thrips parvispinus, Chaetanaphothrips orchidii and Haplothrips gowdeyi began to infest. Shannon and Simpson diversity indices were determined to be -1.739 and -0.1979. According to Shannon index, C. orchidii and T. parvispinus were the first and second predominant species after flowering. Taxonomic investigations of the collected species were done and substantiated with molecular identification of those analyzed species. A phylogenetic tree of the analyzed sequences was constructed to denote species divergence based on their specific sequences.