James A. Cohen

Learn More
Florida queen butterflies are highly variable in cardenolide content and, in three populations studied, contained less cardenolide than did a sample of sympatric Florida monarchs. The possibility that queens stored a more potent set of cardenolides from their host plants (and therefore were as well protected as monarchs, even at lower concentrations) is(More)
Cycnia tenera adults, reared as larvae onAsclepias humistrata, had 10 times higher cardenolide concentrations, and contained 15 times more total cardenolide, than did moths reared onA. tuberosa. Thin-layer chromatography confirmed that each individual cardenolide visualized in the adult moths reared on the former host plant corresponds to one present in the(More)
Most recent treatments of sexual selection theory have focused on the mechanisms of intrasexual (male) competition and female choice (e.g., Williams, 1966, 1975; Maynard Smith, 1978; Searcy, 1982). This is largely attributable to the view that females make a greater gametic investment in the zygote than do males, even when no maternal care is involved, and(More)
  • 1