Plant volatiles mediated the orientation preference of slugs to different plant species

BACKGROUNDSlugs mechanically damage plant leaves, resulting in significant economic losses. However, there are limited cost-efficient strategies available in slug management. By studying how slugs utilize plant volatiles to locate host plants, we can gain insights into the design of attractants and repellents.RESULTSBioassay results suggest slugs (Agriolimax agrestis) prefer to orientate to lettuce (Lactuca sativa), cabbage (Brassica oleracea L.), and young tobacco seedlings, compared with old tobacco seedlings. We analyzed the volatomics of lettuce, cabbage, young and old tobacco seedlings. 2-(2-butoxyethoxy)-ethanol acetate (2EA) had high abundance while nonanal, decanal, and beta-cylocitral had relatively low content in volatiles. Old tobacco seedlings released significantly more hexanal but fewer 1,4-dihydro-4-oxopyridazine (DO). In olfactory tests, hexanal, nonanal, decanal, and beta-cylocitral showed strong repellency to slugs, while DO at a dose of 500 ng/mu L and 2EA at a dose of 1% were attractive to slugs. The two alkanes, hexadecane and heptadecane, had no effect on slug orientating to host plants. DO and 2EA can thus alleviate the repellency of hexanal, nonanal, decanal and beta-cylocitral.CONCLUSIONThe high emission of hexanal in old tobacco seedlings helps repel slugs, while 2EA and DO attract slugs to lettuce and cabbage. These findings suggest that these chemicals can be utilized in the design of repellents and attractants, and contribute to constructing a push-pull system for slug control. (c) 2023 Society of Chemical Industry. The size of words indicates the relative content of chemicals. The red words represent repellent chemicals and green words represent chemicals that are attractive to slugs. Highly released hexanal by non-host plants was found to repel slugs, while 2-(2-butoxyethoxy)-ethanol acetate (2EA) and 1,4-dihydro-4-oxopyridazine (DO) favor slugs to locating their host plants under dark.dagger image