Biological control potential of entomopathogenic nematodes against the striped flea beetle, Phyllotreta sinuata Stephens (Coleoptera: Chrysomelidae)

Abstract The striped flea beetle, Phyllotreta sinuata is a serious pest of Chinese radish production. This insect larvae feed on roots of the host plant, pupate in the soil and adults live close to the soil surface. This study evaluated the efficacy of three entomopathogenic nematodes (EPN); Steinernema siamkayai, S. carpocapsae, and Heterorhabditis indica against various stages of P. sinuata. The results showed that all three EPN species were able to kill third-instar larvae, pupae and adults of P. sinuata under laboratory conditions. Larvae of P. sinuata were more susceptible to all three EPN species than the other two stages. Field evaluations indicated a reduction of P. sinuata populations and a decrease of root damaged length caused by the larvae of P. sinuate after 40 days of exposure. Furthermore, root weight and root diameter of Chinese radish in treatments with S. carpocapsae were higher than control treatments. This study presents evidence for the potential use of the three EPN species as bio-agents against P. sinuata on Chinese radish production in Thailand.