Phosphine Resistance in Rusty Grain Beetle, Cryptolestes ferruginous in Andhra Pradesh, India

摘要

The populations of rusty grain beetle, Cryptolestes ferrugineus (Stephens) were collected from the store houses of Charlapalli, Machilipatnam and Samarlakota during 1995-1997 and assessed the development of resistance to phosphine. The Machilipatnam and Samarlakota strains in comparison with Charlapalli strain showed x 39.59 and x 24.54 fold resistance at LC_(50) level and x 51.87 and x 47.74 fold resistance at LC_(99.9) level. Machilipatnam, Samarlakota and Charlapalli strains developed x 228.25, x210.03 and x4.40 fold resistance to phosphine, respectively when compared with (C x t) discriminating concentration x time product of 1.2 x 20 mg h/l.