Eco-friendly management of cardamom root grub (Basilepta fulvicorne Jacoby) through entomopathogenic nematodes

Abstract

Studies on the infective juvenile (IJs) of entomopathogenic nematodes attachment, penetration into root grub and infectivity of eight native EPNs namely, Heterorhabditis sp. (IISR-EPN 01), Steinernema sp. (IISR-EPN 02), S. ramanai (IISR-EPN 03), S. carpocapsae (IISR-EPN 06), Oscheius gingeri (IISR-EPN 07) and Oscheius spp. (IISR-EPN 04, 05, and 08) were tested against cardamom root grub. Among the tested EPNs, maximum number of O. gingeri (IISREPN 07) IJs attached, followed by Heterorhabditis sp. (IISR-EPN 01) after 3 h of inoculation. Maximum number of Heterorhabditis sp. (IISR-EPN 01) IJs penetrate into grub, followed by O. gingeri (IISR-EPN 07). The lowest rate of penetration was found in the Oscheius sp. (IISR-EPN 05). In case of infectivity of EPNs, Heterorhabditis sp. (IISR-EPN 01) and O. gingeri (IISR-EPN 07) caused 100 % mortality to root grub, followed by S. ramanai (IISR-EPN 03) (83%). Whereas, Steinernema sp. (IISR-EPN 02), S. carpocapsae (IISR-EPN 06) and Oscheius sp. (IISR-EPN 08) brought about 67% mortality. However, Oscheius spp. (IISR-EPN 04 and 05) kill only 50% root grub after 72 h. Infectivity of these EPN against cardamom root grub is being reported for the first time. This opens a new non chemical option for management of insect pests of cardamom.