Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 1995 Jan 3;92(1):50-5.
doi: 10.1073/pnas.92.1.50.

The Chemistry of Sexual Selection

Free PMC article

The Chemistry of Sexual Selection

T Eisner et al. Proc Natl Acad Sci U S A. .
Free PMC article


The moth Utetheisa ornatrix (Lepidoptera: Arctiidae) is protected against predation by pyrrolizidine alkaloids that it sequesters as a larva from its foodplants. At mating, the male transfers alkaloid to the female with the spermatophore, a gift that the female supplements with alkaloid of her own and transmits to the eggs. Eggs are protected as a result. The male produces a pheromone, hydroxydanaidal, that he derives from the alkaloid and emits from a pair of extrusible brushes (coremata) during precopulatory interaction with the female. Males rendered experimentally alkaloid-free fail to produce the pheromone and are less successful in courtship. The male produces the pheromone in proportion both to his alkaloid load and to the amount of alkaloid he transfers to the female. The pheromone could thus serve as an indication of male "worth" and provide a basis for female choice. Utetheisa females are promiscuous and therefore are able to accrue multiple nuptial gifts (alkaloid and nutrient, both transmitted with the spermatophore). They use sperm selectively, favoring those of larger males. Larger males in nature are also richer in alkaloid. Females therefore reinforce after copulation the choice mechanism they already exercise during courtship.

Similar articles

See all similar articles

Cited by 48 articles

See all "Cited by" articles


    1. Proc Natl Acad Sci U S A. 1991 Oct 15;88(20):9224-7 - PubMed
    1. Proc Natl Acad Sci U S A. 1993 May 15;90(10):4689-92 - PubMed
    1. Proc Natl Acad Sci U S A. 1988 Aug;85(16):5992-6 - PubMed
    1. J Lipid Res. 1964 Jan;5:3-19 - PubMed
    1. Proc Natl Acad Sci U S A. 1995 Jan 3;92(1):14-8 - PubMed

Publication types

LinkOut - more resources