M. Panzuto et al., Perception of aspen and sun/shade sugar maple leaf soluble extracts by larvae of Malacosoma disstria, J CHEM ECOL, 27(10), 2001, pp. 1963-1978
We investigated the behavioral feeding preference and the chemoreception of
leaf polar extracts from trembling aspen, Populus tremuloides, and from su
n and shade sugar maple, Acer saccharum, by larvae of the polyphagous fores
t tent caterpillar, Malacosoma disstria, a defoliator of deciduous forests
in the Northern Hemisphere. Three polar extracts were obtained from each tr
ee species: a total extract, a water fraction, and a methanol fraction. M.
disstria larvae were allowed ad libitum access to an artificial diet from e
closion to the fifth instar. Two-choice cafeteria tests were performed comp
aring the mean ( SE) surface area eaten of the total extracts, and the foll
owing order of preference was obtained: aspen > sun maple > shade maple. Te
sts with the other fractions showed that M. disstria larvae preferred the t
otal aspen extract to its water fraction, and the latter to its methanol fr
action. The response to sun maple was similar to aspen. However, for the sh
ade maple experiment, there was no difference between the total extract and
its water fraction. Electrophysiological recordings for aspen showed that
the sugar-sensitive cell elicited more spikes to the water fraction, follow
ed by the total extract, and finally the methanol fraction, Spike activity
to stimulations of sun and shade maple extracts revealed a similar trend, w
here methanol fraction > water fraction > total extract Our findings are di
scussed in light of previously known information about this insect's perfor
mance on these host plants.