DO ROOT-EMITTED VOLATILE ORGANIC COMPOUNDS ATTRACT WIREWORMS?

摘要

Wireworms are the larvae of click beetles (Coleoptera: Elateridae). Their worldwide importance as belowground crop pests is well documented. Resort to insecticides for their management has considerably decreased and alternatives to synthetic chemicalshave emerged. Many IPM approaches have already proven to be useful at field scale while some need improving. More efficient integrated management could be undertaken if gaps of knowledge in wireworm biology and ecology were filled (Furlan 2005). Research could beneficiate from new insights in wireworms' chemical ecology, especially regarding their food searching behaviour. Wireworms are likely to orientate towards food through a three-step mechanism (Johnson and Gregory, 2006). First, carbon dioxide gradients originating from roots or any other belowground plant organ biases their random movement (Doane et al., 1975). The second step involves the perception of specific semio-chemicals, including volatile organic compounds (VOC) or root exudates residues. Finally, root surface chemosensory cues act as influencers of acceptance or rejection of the host plant (Johnson and Gregory 2006). Several plant-produced substances have been shown to elicit an orientation or a biting response (Thorpe et al., 1946;Johnson et al., 2008), but the role of root-emitted VOC remains unclear.