Gy. Zhao et al., INSECTICIDE RESISTANCE IN-FIELD AND LABORATORY STRAINS OF WESTERN FLOWER THRIPS (THYSANOPTERA, THRIPIDAE), Journal of economic entomology, 88(5), 1995, pp. 1164-1170
Western flower thrips, Frankliniella occidentalis (Pergande), from 5 c
ommercial greenhouses were resistant to diazinon, methomyl, bendiocarb
, and cypermethrin, except in 2 tests with bendiocarb. When compared w
ith the UMC-A reference strain, resistance ratios from LC(90)s (RR(90)
) at 24 h ranged from 10.4 to 98 for diazinon, 3.4 to 26 for methomyl,
0.9 to 11 for bendiocarb, and 18.3 to 273 for cypermethrin. We also d
id toxicity studies on 2 laboratory strains (UMC, KCM). Compared with
the UMC-A strain, RR(90)s indicated that UMC thrips were resistant to
diazinon (14-fold), methomyl (3.6-fold), and cypermethrin (232-fold),
but not to bendiocarb. The RR(90) of KCM thrips reared under diazinon
selection increased from 4.0 to 271 when compared with UMC-A thrips. D
uring diazinon selection, cross-resistance to bendiocarb was evident,
with the RR(90) increasing from 0.4 to 14. Cross-resistance to cyperme
thrin also was present at the LC(50) (3.9-fold), but not at the LC(90)
. When compared with UMC thrips, KCM thrips also were resistant to per
methrin (RR(90) = 2.5), fenvalerate (RR(90) = 3.6), DDT (RR(90) = 6.0)
, and imidacloprid (RR(90) = 14), but not to amitraz. Piperonyl butoxi
de, but not S,S,S-tri-n-butyl phosphorotrithioate, synergized the toxi
city of diazinon, bendiocarb, and fenvalerate to KCM thrips.