Infectivity of Spodoptera litura (F.) (Lepidoptera: Noctuidae) by certain native entomopathogenic nematodes and their penetration in test insect and in vivo production.

A study was conducted to assess the susceptibility of tobacco caterpillar, Spodoptera litura (F.) to Steinernema mushtaqi, S. masoodi, S. seemae and S. carpocapsae (Lucknow strain) and in vivo production of these species carried out during the year 2007. On exposure of the insect pest at a dose of 100 IJs/ml each of S. masoodi and S. mushtaqi were found lethal against S. litura, and cent per cent mortality after 72 h post exposure. The rest of test EPN species brought cent per cent to insect mortality after 96 h. Observation on in vivo production on tobacco catterpillar showed that, highest yield of S. mushtaqi (0.79 X 105 IJs/ cadaver was obtained, followed by S. seemae, (0.72 X 105 IJs/ cadaver), S. carpocapsae, (0.67 X 105 IJs/cadaver) and S. masoodi, (0.51 X 105 IJs/ cadaver). The rate of penetration of these species inside the S. litura larvae was also evaluated. Among these, S. masoodi was found highest value (14.41±2.99; CV = 20.74 %), followed by S. mushtaqi (11.25±4.82; CV = 42.84 %). This is the first report on infectivity of tobacco caterpillar by four native species of EPNs and using the insect as a host for culturing these nematodes.