A research team at the University of California, Riverside has found a new tool that targets the Asian Citrus Psyllid's (ACP’s) olfactory system, and they’ve have identified a suite of odorants (odor molecules) that the insect detects. Some of these odorants can modify the behavior of ACP and may lead to the development of tools to tackle its spread. The ACP olfactory system is sensitive to a variety of odorants released by citrus plants. This presents an opportunity to develop attractants and repellents using odors. The ACP detects citrus-plant odors using tiny sensors on its antennae. The Universities lab performed a large-scale analysis of numerous citrus-emitted odors and identified the ones that strongly activate the neurons on the ACP antennae. Then, using a blend of activating odorants, the researchers developed an efficient attractant that could lure the ACP to sticky traps. This odor-based insect lure could be of use to growers in California and other parts of the world where ACP invasion is occurring.
The blend of odors the team of researchers identified consisted of myrcene, ethyl butyrate and p-cymene — odors found in nature. To test whether this blend was indeed effective as an attractant, the team performed field trials on citrus trees in a residential neighborhood in El Monte, Calif. They found that the odor-based traps caught nearly 230 percent more ACPs than conventional traps placed on the same trees. What’s particularly encouraging is that these three chemicals are affordable, useful in small quantities, and safe for human handling. They could be developed into monitoring and surveillance tools. Similar approaches can be taken to develop control strategies using odors for other insect pests of crops as well. The study also reports identification of odors that block the ACP olfactory system from detecting citrus odors and have potential for development into repellents. -Millet
