A. Tsagkarakou et al., GENETIC-VARIABILITY IN TETRANYCHUS-URTICAE (ACARI, TETRANYCHIDAE) FROM GREECE - INSECTICIDE RESISTANCE AND ISOZYMES, Journal of economic entomology, 89(6), 1996, pp. 1354-1358
Resistance to methyl-parathion, methidathion, and methomyl was studied
by bioassays in Tetranychus urticae Koch from Greece. At LC(50), the
resistance ratio was highly variable with methidathion (5- to 63-fold)
and with methomyl (6- to 34-fold). The mortality curves with methyl-p
arathion showed a clear plateau at approximate to 20% mortality, and t
he resistance ratio was approximate to 50 fold at LC(50) in all sample
s. By using isoelectric focusing on cellulose acetate membranes, elect
rophoretic studies of 5 loci encoding esterases (Est-1 and Est-2), glu
cose-phosphate isomerase (Gpi), malic enzyme (Me), and phosphoglucomut
ase (Pgm) disclosed large genetic differences among the samples.