The Antifeeding Activity and Eletrophysiological Response of Synthetic Polyacetylenes Against Ostrinia furnacalis

The first attempt to study the activity of new synthetic compounds of nine conjugated diacetylenes and three single acetylenes against the 5th instar larvae of Ostrinia furnacalis with the methods of behavioral bioassay and electrophysiological observation was reported. The result shows that compound 2 (6,6-dimethyl-2,4-heptadiyne-1-ol), compound 3 (2,4-hexadiyne-1,6-diol), compound 9 (1-phenyl-2,4-hexadiyne) and compound 11 (3-bromo-2-propyne-1-ol), of those compounds have significantly antifeeding activity against the insect. The antifeeding index is about 80 percent at the dose of 500 μg/g. When comparing the impulse frequency of medial maxillary sensillum of the larvae stimulated with different compounds and activity of behavioral bioassay, it is found that the impulse frequencies correlated well with their antifeeding activity in behavioral test. Electrophysiological study also demonstrates that those compounds with activity can stimulate deterrent cells in the medial maxillary styloconic sensilla as well as inhibit the sensitive cell in the lateral maxillary styloconic sensilla. The medial and lateral maxillary styloconic sensilla control and regulate commonly the feeding behaviors of the insect.