Insecticide Resistance in the Pear Psylla1
- 1 February 1965
- journal article
- research article
- Published by Oxford University Press (OUP) in Journal of Economic Entomology
- Vol. 58 (1) , 172-173
- https://doi.org/10.1093/jee/58.1.172
Abstract
In the State of Washington strains of the pear psylla, Psylla pyricola, have become highly resistant to one insecticide after another. In 1963 LD50''s of Guthion (O,O-dimethyl S-(4-oxo-l,2,3-benzotriazin-3(4H)-ylmethyl) phosphorodithioate) against pear psylla, expressed in pounds of 25% Guthion wettable powder per 100 gal. of spray, were determined in an unsprayed orchard and in several orchards previously sprayed beginning from 1959 to 1961. Insects with an LD50 of 0.81 or less appeared to be still susceptible to control with Guthion, but those with higher LD50''s demonstrated considerable resistance to this organophos-phate.This publication has 1 reference indexed in Scilit:
- Effects of Some Antibiotics on Three Aphid SpeciesJournal of Economic Entomology, 1963