An emerging pest of radish, striped flea beetle Phyllotreta striolata (Fabricius), from Northern India: incidence, diagnosis and molecular analysis

Abstract

Severe incidence of striped flea beetle, Phyllotreta striolata (Fabricius) (Coleoptera: Chrysomelidae) in radish is being reported from Delhi National Capital Region and Haryana. The larvae and adult of this species were found to damage both roots and leaves of radish, respectively. Overall there was an average 63.02 percent leaf infestation and 53.96 percent root infestation in the radish fields surveyed, which was above the economic threshold level (25% infestation). Infestation was also observed on other cruciferous crops like turnip, mustard, cabbage and cauliflower in National Capital Region and Haryana. In the present study, we have furnished the species diagnosis, sexual dimorphism, nature of damage and illustrations of various stages of the pest. DNA barcoding was employed to confirm the species identity and molecular phylogenetic studies based on mt CO I sequences from across the world showed that there were two clusters; the Old World and the New World. The biology of the pest and the importance of studies on area specific population dynamics for formulating management strategies are discussed.