The effect of patch size and persistence of host plants on the developmentof acaricide resistance in the two-spotted spider mite Tetranychus urticae(Acari : Tetranychidae)
K. Goka, The effect of patch size and persistence of host plants on the developmentof acaricide resistance in the two-spotted spider mite Tetranychus urticae(Acari : Tetranychidae), EXP APPL AC, 23(5), 1999, pp. 419-427
Spatial and temporal characteristics of host plants can influence the popul
ation biology of the herbivores feeding on them. In this study, I examined
the effect of variation in host plant characteristics on the development of
acaricide resistance in the two-spotted spider mite Tetranychus urticae, a
widely distributed agricultural pest. This investigation examined the geog
raphic variation in the degree of resistance to two new types of acaricide,
pyridaben and fenpyroximate. From mortality tests at field-level concentra
tions of the acaricides, many populations collected from fruit trees and ro
ses had a high frequency of resistant individuals for acaricides while almo
st all populations collected from herbaceous crops had low frequencies of r
esistant individuals. These results, combined with those from a previous al
lozyme study, indicate that patch size and persistence of host plants regul
ate the population structure of the mites including gene flow between popul
ations and, by extension, the development of acaricide resistance.