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.

Quantification of contact oviposition stimulants for black swallowtail butterfly,Papilio polyxenes, on the leaf surfaces of wild carrot,Daucus carota.

Ovipositing black swallowtail butterflies,Papilio polyxenes, make their final host-selection decisions on the basis of compounds present on the leaf surface. Little information is available, however, on the chemistry of leaf surfaces. The purpose of this study was to develop a technique to extract and quantify the concentrations of compounds from the leaf surfaces ofDaucus carota, one of the main host species forP.