Although pulmonate molluscs are the principal seedling herbivores in temperate grasslands and agriculture, we understand little about what drives seedling selection. Shannon et al. examined the roles of constitutive chemical defences (glucosinolates) and volatiles (volatile organic compounds (VOCs)) in the attractiveness of oilseed rape (Brassica napus) seedlings to snails (Helix aspersa).
While glucosinolates had no effect, VOCs related to snail selective preferences were identified and a blend of ‘repellent’ VOCs (mainly green leaf volatiles) reduced snail selection in olfactometer choice tests. The study highlights the possibility of modifying the VOC profile of crop seedlings to reduce damage by agricultural pests.
See also Futurity: Pesky snails pick food by smell not taste
Roger W. R. Shannon, Anne-Emmanuelle Félix, Guy M. Poppy, Philip L. Newland, Nicole M. van Dam, Mick E. Hanley, 2016, 'Something in the air? The impact of volatiles on mollusc attack of oilseed rape seedlings', Annals of Botany, vol. 117, no. 6, pp. 1073-1082 http://dx.doi.org/10.1093/aob/mcw032