Chemical basis of courtship in a beetle (Neopyrochroa flabellata): Cantharidin as "nuptial gift".

The amount of cantharidin (Spanish fly) that the Neopyrochroa flabellata male presents to the female as a glandular offering during courtship represents only a small fraction of the total cantharidin the male accumulates systemically following ingestion of the compound. A major fraction of the acquired cantharidin is stored by the male in the large accessory glands of the reproductive system. At mating, the male transfers this supply, presumably as part of the sperm package, to the spermatheca of the female. The female in turn allocates the gift to the eggs. Eggs endowed with cantharidin proved relatively invulnerable to attack by a predaceous beetle larva (Coleomegilla maculata).

Sodium: a male moth's gift to its offspring.

Males of the moth Gluphisia septentrionis acquire sodium by drinking from mud puddles. Analyses of male and female bodies indicate that such "puddling" behavior enables the male to provide his mate with a nuptial gift of sodium, presumably via the spermatophore. This gift (about 10 microg), amounting to more than half of a puddler male's total body sodium, is in large measure apportioned by the female to her eggs. Puddler-sired eggs contain 2 to 4 times more sodium than those control-sired; this difference is already apparent in eggs laid the night after mating. Paternal endowment of offspring with sodium had not previously been demonstrated for an insect to our knowledge. The potential adaptive significance of such chemical bestowal is evident, given that the foliar diet of G. septentrionis larvae is extremely low in sodium content.