Glucosinolates and trichomes track tissue value in two sympatric mustards.

Glucosinolates, trichomes, nitrogen, and carbon are not distributed uniformly through the canopies of mustards. In this study, we asked whether glucosinolate concentrations and trichome densities in two sympatric mustards, Brassica kaber and B. nigra, are highest in tissues of greatest value to the plant.

From terpenoids to aliphatic acids: further evidence for late-instar switch in osmeterial defense as a characteristic trait of swallowtail butterflies in the tribe papilionini.

We compared the chemical compositions of the osmeterial secretions of fourth and fifth (last) instars of eight swallowtail species of the tribe Papilionini. Four species (Papilio demoleus, P. polytes, P.

Combined roles of contact stimulant and deterrents in assessment of host-plant quality by ovipositing zebra swallowtail butterflies.

Zebra swallowtail (Eurytides marcellus) butterflies are stimulated to oviposit by a single compound, 3-caffeoyl-muco-quinic acid (1). Analysis of the aqueous extracts of the leaves of the host. Asimina triloba, showed that they contained stimulant 1, its isomer (2), and the flavonoids rutin (3) and nicotiflorine (4) as major components.

Effects of benzylisoquinoline alkaloids on the larvae of polyphagous Lepidoptera.

Six benzylisoquinoline alkaloids were fed to the larvae of three polyphagous Lepidoptera species: Hyphantria cunea, Spodoptera eridania, and Lymantria dispar. Exposure of last instar larvae to alkaloid-containing diets over a 24-h period resulted in reduced feeding rates and reduced growth efficiencies. Lymantria dispar larvae reared from eggs on alkaloid diets took longer to reach the fifth instar, attained lower larval weights, and showed reduced survivorship.