Use of Steinernema and Heterorhabditis nematodes for control of white grubs, Brahmina coriacea hope (Coleoptera: Scarabaeidae) in potato crop

The efficacy of the entomopathogenic nematodes (EPN) Steinernema carpocapsae and Heterorhabditis indica against different developmental stages of Brahmina coriacea Hope (Coleoptera: Scarabidae) were evaluated under laboratory and field conditions. In laboratory studies, significant mortality by S. carpocapsae (68–93%) and H. indica (39–71%) after 7 days of treatment was observed at three dosages viz.; 500, 1000 and 2000 infective juveniles (ij)/100g soil. In field (Fagu and Shimla), all the three dosages of S. carpocapsae and H. indica (1, 3 and 6×10⁵ij/m²) were effective in reducing the grub population, percent plant damage as well as percent tuber damage. Percent reduction in grub population was 66–80% due to H. indica and more then 83% due to S. carpocapsae at Fagu. There was more than 60 and 50% reduction in grub population due to S. carpocapsae and H. indica treatment in 2007 and more than 80% in 2008 at Shimla in plots treated with both the EPN spp. at normal harvesting time. The least number of grubs and damaged tuber were recorded in case of treatment with S. carpocapsae @ 6×10⁵ ij/m² during both the years at Fagu as well as Shimla.