Stability and persistence of aldrin and methyl-parathion resistance in western corn rootworm populations (Coleoptera: Chrysomelidae)

Abstract

The susceptibilities of laboratory and field-collected western corn rootworm populations (Diabrotica virgifera virgifera LeConte) to methyl-parathion and aldrin were estimated by topical application of insecticide during 2002 to determine the stability of resistance in the absence of selective pressures. Most of the laboratory-reared and field-collected populations were significantly resistant to both insecticides. Average LD 50 values of laboratory and field-collected populations were 19-and 13-fold greater than the susceptible population in methyl-parathion bioassays, respectively, and 204-and 125-fold greater in the aldrin bioassays, respectively. The presence of aldrin and methyl-parathion resistance in field-collected populations strongly suggests that both resistance traits are stable in the absence of selection pressure and that neither mechanism is associated with a strong fitness disadvantage. r

Increased survival of western corn rootworm on transgenic corn within three generations of on-plant greenhouse selection

“…Interestingly, insecticide resistance in this pest may persist for many generations in the absence of selection (10). Here, we describe the evolution of resistance to a low-to-moderate dose Bt product under greenhouse conditions.…”

“…Parimi, et al (10) evaluated laboratory and field strains of WCR for resistance to aldrin and methyl-parathion. As observed in greenhouse results with the Removal from selection colony on Bt corn, resistance to both aldrin and methyl-parathion was relatively stable in the absence of selection pressure.…”

Western corn rootworm and Bt maize

“…45 Parallels may be present with resistance to the insecticide aldrin, which took several generations to build within populations of western corn rootworm but has since persisted for more than 20 y in the absence of selection. 64 While resistance to Cry3Bb1 was associated with three or more years of cultivation for Cry3Bb1 maize, not all fields experience severe rootworm injury to Cry3Bb1 maize ( Table 3). This is to be expected because root injury in the field will be a function of resistance and pest abundance.…”

Comparative efficacy assessment of fungi, nematodes and insecticides to control western corn rootworm larvae in maize

“…Some studies show high efficacies, while others show low efficacies (e.g. for fungi: Krueger and Roberts 1997;for nematodes: Georgis and Gaugler 1991;Wright et al 1993;Jackson and Brooks 1995;Riga et al 2001; for soil insecticides and seed coatings: Zhu et al 2005;Borani et al 2006;Furlan et al 2006;Parimi et al 2006;Van Rozen and Ester 2007). Occasional failures of fungi or nematodes are usually explained by the use of species or strains that are not adapted to the host or to local conditions (Jackson 1995;Shapiro-Ilan et al 2002), by soil aridity and soil texture (Ellsbury et al 1996;Kessler et al 2003;Koppenhöfer and Fuzy 2006) or by the lack of alternative hosts (Brust 1991;Susurluk 2005).…”