Variation in Cardiac Glycoside Content of Monarch Butterflies from Natural Populations in Eastern North America

Brower, Lincoln P.; McEvoy, Peter B.; Williamson, Kenneth L.; Flannery, Maureen A.

doi:10.1126/science.177.4047.426

Cited by 151 publications

(90 citation statements)

References 8 publications

(1 reference statement)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In contrast to these findings, laboratory studies using fifth instar larvae in bioassays found no effect of CG levels in diet, or different Asclepias species, on growth of IV and V instar larvae and fecundity of subsequent adults (Erickson 1973;Cohen 1983). Variation of adult size in the field in relation to CG concentration has been interpreted as indicating a physiological cost (Brower et al 1972), but this has been criticised on various grounds (Dixon et al 1978).…”

Section: Introductionmentioning

confidence: 93%

Survival of first instar larvae ofDanaus plexippus (Lepidoptera: Danainae) in relation to cardiac glycoside and latex content ofAsclepias humistrata (Asclepiadaceae)

Zalucki

Brower

1992

Chemoecology

Self Cite

View full text Add to dashboard Cite

SummaryOur paper addresses field survivorship of first instar monarch butterfly larvae (Danaus plexippus L., Lep.:Danainae) in relation to the dual cardenolide and latex chemical defenses of the sand hill milkweed plant, Asclepias humistrata (Asclepiadaceae) growing naturally in north central Florida. Survival of first instar larvae in the field was 11.5°70 in the first experiment (15-20 April 1990), and dropped to 3.4°7o in the second experiment (20-30 April). About 30°7o of the larvae were found glued to the leaf surface by the milkweed latex. Predator exclusion of non-flying invertebrates by applying "tanglefoot" to the plant sterns suggested that the balance of the mortality was due to volant invertebrates, or to falling and/or moving off the plants. Regression analyses to isolate some of the other variables affecting survivorship indicated that first instar mortality was correlated with (1) increasing cardiac glycoside concentration of the leaves, (2) increasing age of the plants, and (3) the temporal increase in concentration of cardiae glycosides in the leaves. The study also provided confirmatory data of previous studies that wild monarch females tend to oviposit on A. humistrata plants containing intermediate concentrations of cardiac glycosides. Cardiac glycoside concentration in the leaves was not correlated with that in the latex. The concentration of cardenolide in the latex is extremely high, constituting an average of 1.2 and 9.5°70 of the mass of the wet and dry latex, respectively. The data suggest that an increase in water content of the latex is compensated for by an influx of cardenolide with the result that the cardenolide concentration remains constant in the latex systems of plants that are growing naturally. We also observed first instar larvae taking their first bite of milkweed leaves in the field. In addition to confirming other workers findings that monarch larvae possess elaborate "sabotaging" behaviour of the milkweed's latex system, we discovered that several larvae on their first bite involuntarily imbided a small globule of latex and instantly became cataleptic. This catalepsis, lasting up to 10 min, may have been in response to the high concentration of cardenolide present in the latex of A. humistrata, more than 10 times that in the leaves. The results of the present study suggest that more attention should be directed to plant chemical defenses upon initial attack by first instar insect larvae, rather than attempting correlations of plant chemistry with older larvae that have already passed the early instar gauntlet. The first bite of neonate insects may be the most critical moment for coping with the chemical defenses of many plants and may play a much more important role in the evolution of insect herbivory than has previously been recognized.

show abstract

Section: Introductionmentioning

confidence: 93%

Survival of first instar larvae ofDanaus plexippus (Lepidoptera: Danainae) in relation to cardiac glycoside and latex content ofAsclepias humistrata (Asclepiadaceae)

Zalucki

Brower

1992

Chemoecology

Self Cite

View full text Add to dashboard Cite

show abstract

“…Individual plant and butterfly samples were prepared and extracted with 95 % ethanol as described by Brower et al (1972). Spectrophotometric determinations of cardenolide concentrations in the [1983][1984] samples were performed at 20 °C and 622 nm with alkaline 2,2'-,4,4'-tetranitrodiphenyl (TNDP) on a Perkin Elmer 559A spectrophotometer as described in Brower et al (1972, Brower & Moffitt (1974), Lynch & Martin (1987) and .…”

Section: Determination Of Total Cardenolide Contentmentioning

confidence: 99%

Cardenolide content, emetic potency, and thin-layer chromatography profiles of monarch butterflies,Danaus plexippus, and their larval host-plant milkweed,Asclepias humistrata, in Florida

et al. 1992

Self Cite

View full text Add to dashboard Cite

SummaryThis paper is the fourth in a series on cardenolide fingerprints of monarch butterflies (Danaus plexippus, Danainae) and their host-plant milkweeds (Asclepiadaceae) in the eastern United States. Cardenolide concentrations of Aselepias humistrata plants from north central Florida ranged from 71 to 710 gg/0.1 g dry weight, with a mean of 417 gg/0.1 g. Monarchs reared individually on these plants contained cardenolide concentrations ranging from 243 to 575 gg/0.1 g dry weight, with a mean of 385 gg/0.1 g. Cardenolide uptake by butterflies was independent of plant concentration, suggesting that sequestration saturation occurs in monarchs fed cardenolide-rich host plants. Thinlayer chromatography resolved 19 cardenolides in the plants and 15 in the butterflies. In addition to humistratin, A. humistrata plants contained several relatively non-polar cardenolides of the calotropagenin series which are metabolized to more polar derivatives in the butterflies. These prodnced a butterfiy cardenolide fingerprint clearly distinct from those previously established for monarchs reared on other Asclepias species. In emetic assays with the blue jay, Cyanocitta cristata, the 50°70 emetic dose (EDso) per jay was 57.1 gg, and the average number of ED»o units per butterfly was 13.8, establishing that this important south eastern milkweed produces highly emetic, chemically defended monarchs. Our data provide further support for the use of cardenolide fingerprints of wild-caught monarchs to make ecological predictions concerning defence against natural enemies, seasonal movement and larval host-plant utilization by monarch butterflies during their annual cycle of migration, breeding and overwintering.

show abstract

“…A recent study (3) has shown that monarch butterflies from natural populations exhibit palatability spectra and include individuals that are only moderately unpalatable. A predator might have to experience more than one of these before it was conditioned to avoid subsequent individuals.…”

mentioning

confidence: 99%

Theoretical Investigations of Automimicry: Multiple Trial Learning and the Palatability Spectrum

Pough

Brower

Meck³

et al. 1973

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

View full text Add to dashboard Cite

show abstract

Variation in Cardiac Glycoside Content of Monarch Butterflies from Natural Populations in Eastern North America

Cited by 151 publications

References 8 publications

Survival of first instar larvae ofDanaus plexippus (Lepidoptera: Danainae) in relation to cardiac glycoside and latex content ofAsclepias humistrata (Asclepiadaceae)

Survival of first instar larvae ofDanaus plexippus (Lepidoptera: Danainae) in relation to cardiac glycoside and latex content ofAsclepias humistrata (Asclepiadaceae)

Cardenolide content, emetic potency, and thin-layer chromatography profiles of monarch butterflies,Danaus plexippus, and their larval host-plant milkweed,Asclepias humistrata, in Florida

Theoretical Investigations of Automimicry: Multiple Trial Learning and the Palatability Spectrum

Contact Info

Product

Resources

About