Abstract

Spodoptera litura (Noctuidae Lepidoptera) is a notorious leaf damaging pest on tomato. A new biological insecticide molecule, spinetoram 12 SC was evaluated for acute toxicity on laboratory reared S. litura population, and persistence on tomato leaves at laboratory conditions; and effect on S. litura on tomato at field conditions during 2011 and 2012 seasons. Acute toxicity studies revealed that LC50`s of spinetoram on third instar larvae after 24, 48 and 72 hours after treatment were 8.56, 5.86 and 3.70 ppm respectively. In persistence studies, there was reduction in the mortality of larvae as the time increased and there was no mortality after 21 DAT in spinetoram 45 and 54 g a.i/ha and after 14 DAT in spinetoram 36 g a.i/ha, novaluron and quinalphos. In the field, spinetoram 12 SC was applied as foliar spray at 36 g a.i./ha, 45 g a.i./ha and 54 g a.i./ha. Spinetoram 12 SC was significantly effective at 45 and 54 g a.i./ha when sprayed thrice at 15 days interval and minimized the incidence of S. litura on tomato plants.

Keywords: Spinetoram, Tomato, Acute toxicity, Persistence, Field efficacy, Spodoptera litura