F. Dagli et I. Tunc, Dicofol resistance in Tetranychus cinnabarinus: resistance and stability of resistance in populations from Antalya, Turkey, PEST MAN SC, 57(7), 2001, pp. 609-614
Resistance against dicofol was investigated in the carmine spider mite, Tet
ranychus cinnabarinus. Higher resistance levels were detected by leaf resid
ual bioassays than by topical bioassays, both done using a Potter spray tow
er, in almost all populations of T cinnabarinus examined from Antalya, Turk
ey. For instance, the resistance level at LC95 was 17.5-fold in topical bio
assays but 58.9-fold in leaf residual bioassays for the population collecte
d from greenhouses in the Topcular district. There were differences of resi
stance levels at LC95, ranging between 2.6- and 23.9-fold using topical bio
assays and between 5.0- and 58.9-fold in residual bioassays, in populations
collected from greenhouses from various districts. Populations from cotton
showed lower resistance levels against dicofol than populations from green
houses.
Resistance to dicofol at LC50 as indicated by topical and residual bioassay
s increased 19.7- and 100.7-fold, respectively, in a colony from the labora
tory strain of T cinnabarinus selected with dicofol alone for 16 cycles. Ho
wever, the dicofol resistance at LC50 increased 19.4- and 52.0-fold in anot
her colony selected in rotation with dicofol and tetradifon for six and eig
ht cycles, respectively. The changes in resistance to dicofol 5 months afte
r the selection ceased were as follows: in the colony selected for dicofol
alone, using topical and residual bioassays, the resistance levels at LC50
decreased to 11.7- and 99.1-fold, respectively, and in the colony selected
in rotation with dicofol and tetradifon to 10.8- and 15.8-fold, respectivel
y.
(C) 2001 Society of Chemical Industry.