Abstract
Scolus secretions and hemolymph of caterpillars of Satumia pyri fed with two different foodplants (Crataegus monogyna, Prunus spinosa) were chemically analyzed and their chemical similarities determined. The secondary-compound patterns obtained for the two body fluids showed no significant differences when compared between the two groups of alterna tively fed last-instar larvae. Thus, the composition of these fluids of full-grown caterpillars is not influenced by the larval diet. However, younger larvae on P. spinosa revealed a diversity of compounds differing significantly from that of larger caterpillars fed with either C. monogyna (both body fluids) or P. spinosa (hemolymph only). This indicates that, on the one hand, the hemolymph composition is adapted to the changing physiological requirements of the given instars whereas, on the other hand, the defensive mixtures remain unaltered in the late larval instars due to a constant spectrum of potential enemies.
Proximity to canopy mediates changes in the defensive chemistry and herbivore loads of an understory tropical shrub,
Piper kelleyi
