Cross-Resistance Shown by Aldrin-Resistant Seed Maggot Flies, Hylemya spp., to Other Cydodiene Insecticides and Related Materials1

Abstract
Laboratory tests on adult seed maggots, Hylemya spp., resistant to aldrin (✕209 at LD50) established that cross-resistance occurs with other cyclodiene insecticides and some related materials. The levels of cross-resistance were heptachlor ✕214; heptachlor epoxide ✕174; dieldrin ✕120; endrin ✕9.6; Telodrin® (1,3,4,5,6,7,8,8-octachloro-1,3,3a,4,7,7a,-hexahydro4,7-methanoisobenzofuran) ✕ 7.9; lindane ✕5.5; and endosulfan ✕1.7. The slope of the regression lines for the resistant Delhi strain was lower than that obtained with the susceptible strain. This resulted because an average 10% of the population was susceptible.