The development of preventive methods against the invasive wood-boring beetle Aromia bungii, which infests Rosaceae trees, is required in Japan. We investigated the effect on eggs of several commercial insecticides whose active ingredients are registered to kill A. bungii adults or larvae by tree injection or spray. The ovicidal activity was evaluated using the corrected egg hatch rates based on the control (distilled water) after dipping pieces of cardboard, on which eggs were deposited, in liquid insecticide solutions for 10 sec. The egg-dipping tests revealed highly effective ovicidal activity in the following insecticides: more than 8000 ppm for fenitrothion, 1000 ppm for acetamiprid, 400 ppm for clothianidin, and 500 ppm for dinotefuran (corrected egg-hatch rates of approximately less than 5%). In terms of current registration in Japan, only fenitrothion (SUMIPAIN emulsion) and acetamiprid (MATSUGREEN liquid solution 2) by trunk spraying during the A. bungii reproductive period are adulticidal insecticide candidates with preventive potential through incidental ovicidal activity.
A series of N-alkylated octopamine derivatives was synthesized, and the structure–activity relationships of these derivatives with the silkworm Bombyx mori octopamine receptor BmOAR1 were evaluated using a secreted placental alkaline phosphatase reporter assay system. The N-alkyl moiety on the ligand affected the intensity of the agonist activity in the order: CH3>(H)>C2H5. Although linear alkyl chains of C3 or higher did not exhibit any activity, the fixed C3 alkyl group forming a pyrrolidine ring showed significant activity. These results suggest that BmOAR1 has a relatively small space around the amine-binding site, and the alkyl part constituting the cyclic amine could exert the same effect as the small alkyl group.