Selection and genetic analysis of permethrin resistance in Amblyseius fallacis (Garman) (Acari: Phytoseiidae) from Ontario apple orchards

Abstract

Gravid female phytoseiid mites, Amblyseius faUacis (Garman), were selected for resistance to permethrin using a table-top Petri dish (PD) technique. After 55 seleetious, the LCs0 of the R population increased 964-fold to 12 241 p.p.m. (I'D) and 3.6-fold to 167 p.p.m, by a slide-dip (SD) method. A genetic analysis was conducted to examine the mode of inheritance by a series of singlepair reciprocal interstrain crosses and backerosses of female FI progeny. Concentration-mortality regressions (PD) for parental populations showed a 69.4-fold difference between R and S strains. Regressions for F1 females resulting from both intersWain crosses were intermediate between parental swains and not significantly different, showing no obvious maternal effect. Resistance in the R strain was not completely dominant or recessive and the estimated dominance, D, for the FI females from combined data of both reciprocal crosses was -0.18, for the female R x male S cross it was 0.24 and for the female S × male R cross it was -0.01. We concluded that more than one gene was responsible for the resistance in the selected R strain. No incompatibility was observed in any reciprocal interstrain crosses or baekerosses between the S strain and R strain.

Functional and numerical responses do not always indicate the most effective predator for biological control: an analysis of two predators in a two‐prey system

“…The A. fallacis colony was started in 1993 from mites collected in Jordan, Ontario, Canada (Thistlewood, Pree & Crawford 1995). The Ty.…”

Rencently-proposed methods and concepts of testing the effects of pesticides on the beneficial mite and insect species: Study limitations and implications in IPM.

“…Unlike the methods in which a pesticide is topically applied or contacted as a residue on a treated surface, the slide dip is unsuitable for selection projects because mites are glued down and survivors are incapable of reproduction. Procedure and protocols of slide and petri dish assays for measuring resistance to permethrin in Amblyseius fallacis and selection of permethrin resistance were investigated and compared in detail (Thistlewood et al, 1992(Thistlewood et al, , 1995. In France, Malezieux et al (1992) investigated the toxicity of a number of insecticides, acaricides and fungicides against P. persimilis under laboratory and field conditions.…”

Microsatellite sequences are under‐represented in two mite genomes

“…The mites were mass-reared on bean plants and harvested from the leaves by aspiration under vacuum. The predatory mite A. fallacis originated from a strain collected in Ontario, selected for pesticide resistance (Thistlewood et al, 1995), and mass-reared commercially (Applied BioNomics Ltd, Sidney, B.C.). The predators were reared on bean plants that were infested with T. urticae as prey, and aspirated o leaves.…”