Laboratory and Field Evaluation and Structure-Activity Relationships of Some Aryl Terpenoid Ethers as Insect Growth Regulators Against Anopheles quadrimaculatus, Anopheles albimanus, and Aedes taeniorhynchus13

Abstract

Eleven insect growth regulators of the aryl terpenoid ether type had LC-90 values ≤0.020 ppm in laboratory tests against larvae of Anopheles quadrimaculatus Say; 13 others had LC-90 values <0.100 ppm. In further tests against larvae of An. albimanus Wiedemann and Aedes taeniorhynchus (Wiedemann), 6 aryl ethers containing the 3,4-methylenedioxy group had LC-90 values ≤0.020 ppm in 11 of the 12 tests. 5-[[6-(3,3-Dimethyloxiranyl)-4-methyl-3-hexenyl]oxy]-1,3-benzodioxole showed outstanding activity against all 3 species: LC-90 values ranged from 0.011 to 0.0007 ppm. 3-[6-(3-Ethylphenoxy)-3-methyl-3-hexenyl]-2,2-dimethyloxirane was ineffective against Ae. taeniorhynchus, but it had LC-90 values of 0.001 and 0.0003 against An. quadrimaculatus and An. albimanus, respectively, and was the most active chemical against the 2 anopheline species. In small-plot field tests against An. quadrimaculatus, 5-[[7-(3,3-dimethyloxiranyl)-5-methyl-3-heptenyl]oxy]-1,3-benzodioxole, 3-[6-(3-ethylphenoxy)-3-methyl-3-hexenyl]-2,2-dimethyloxirane, and 2,2-dimethyl-3-[3-methyl-6-(4-propylphenoxy)-3-hexenyl]oxirane were the 3 most effective chemicals and gave 100% control of eclosion at a rate of 56 g/ha and ≥90% control at a rate of 11 g/ha; 5 others gave 100% control at a rate of 112 g/ha.