Chemical Ecology, Plant Protection Science, SLU, P.O. Box 44, 230 53 Alnarp, Sweden.
Anti-feedants as a protection against herbivores have been described in many plants,
well-known is the 'neem' tree Azadiractica indica. In conifers defense is
quantitative, based on less toxic oleoresin compounds. In small, stressed conifers like the
ones planted on clear-cuts in forestry, the quantitative defense is weak. These seedlings
have been defended by insecticides like DDT and pyrethroids against the feeding by pine
weevils Hylobius abietis (causing a 100 million US$/year damage in Sweden),
but use of insecticides will be banned in 2003.
Out work follows two lines: 1) The screening of synthetically available anti-feedant compounds
and related structures. 2) The search for antifeedants in non-host plants. The development
of laboratory bioassays has been a prerequisite for the project. Initially, we modified a twig
technique of Salom et al. (1994). Later, to test small amounts of synthetics
and extracts, we developed a micro feeding assay using TLC-plates. Presently, we are
modifying an olfactometer to investigate the mode of action (taste/smell) of synthetics. Field
tests in 1997 and 1998 demonstrate that formulated feeding deterrents may protect seedlings
for months. The long-term formulation of antifeedants, their mode of action, and finding of
lower volatility compounds remain our goals.
Klepzig, K., & Schlyter, F. 1999. Laboratory evaluation of plant derived
antifeedants against pine weevil Hylobius abietis twig feeding. - J. Econ. Entomol. 92:644-650.