Trapping Lacewings at Tea Plantations by Colored Sticky Boards or Tea Aphid Sex Pheromones

During the prosperous season of lacewings in tea plantations in autumn, sticky boards colored in bud green, earthy yellow, dark green, jasmine yellow, apple green, orange, bright red, peach red, lake blue, purple, sky blue and pure white were placed in the tea plantations to investigate their respective trapping effect on the predators. After 7 consecutive days of the trapping test, the sticky boards in bud green, earth yellow, dark green, and jasmine yellow were found to attract the highest numbers of lacewings, while the pure white board the least. However, the differences were not significant at P< 0.05 level. In parallel, various mixing ratios of the aphid sex pheromones, (4aS, 7S, 7aR)-nepetalactone and (1R, 4aS, 7S, 7aR)-nepetalactol, were made with rubber septas into suspensions to test for their abilities to attract the insects at the tea plantations as well. It was found that Chrysopa sinica Tjeder and Chrysopa septempunctata Wesmael were significantly lured by the blend of (4aS, 7S, 7aR)-nepetalactone and (1R, 4aS, 7S, 7aR)-nepetalactol at the mixing ratio of 1:9. In addition, (1R, 4aS, 7S, 7aR)-nepetalactol displayed a significant attraction in the duration of the experiment. It appeared that the pheromones could be coated on boards without adhesives to collect lacewings for the biocontrol of tea aphids at tea plantations.