†Department of Pure and Applied Biology, Imperial College, Silwood Park, Ascot, Berks., U.K.
Oviposition by Danaus plexippus in relation to cardenolide content of three Asclepias species in the southeastern U.S.A.
Article first published online: 28 JUN 2008
Volume 15, Issue 2, pages 231–240, May 1990
How to Cite
ZALUCKI, M. P., BROWER, L. P. and MALCOLM, S. B. (1990), Oviposition by Danaus plexippus in relation to cardenolide content of three Asclepias species in the southeastern U.S.A. Ecological Entomology, 15: 231–240. doi: 10.1111/j.1365-2311.1990.tb00804.x
- Issue published online: 28 JUN 2008
- Article first published online: 28 JUN 2008
- Accepted 21 June 1989
- Key words. Oviposition;
- Danaus plexippus;
- cardiac glycosides;
Abstract. 1. Female monarchs were observed in the field ovipositing on a native North American milkweek host, Asclepias humistrata L. As in a comparable Australian study on an introduced novel host (Asclepias fruticosa L.) we found post-alighting rejection of plants with low and high cardiac glycoside concentration (CG).
2. Most oviposition took place on plants with CG in the range 200–500 μg/0.1 g dry weight. Thin-layer chromatography showed no obvious qualitative difference in cardenolide types between accepted and rejected plants, excepting an indication that rejected plants may have a higher level of more polar cardenolides.
3. In a controlled laboratory experiment comparing oviposition on a low (A.incarnata L.) vs high (A.curassavica L.) CG host plant species we found no relationship between CG and oviposition on the low CG species, but a negative relationship in the high CG species. This corroborates our findings on oviposition on single host species in the field.
4. We also record the first indication of a physiological cost of monarch larvae feeding on plants high in CG. There was a significant negative relationship between survival of first instar larvae and CG levels in plants. This study opens the way for further work on the association of monarch butterflies and their toxic milkweed hosts.