![]() ![]() Utetheisa can be reared in the laboratory on PA-free or -containing diet ( 12). Females are promiscuous, and as a result are kept infused with PA, even as they relinquish the toxins on an ongoing basis to the eggs ( 3, 11). ![]() ![]() To provision the eggs, the female resorts not only to PA that she herself sequestered as a larva, but to supplementary PA that she receives from the male with the spermatophore at mating ( 7, 10, 11). The chemicals protect larvae and adults against spiders ( 4, 5) and protect the eggs against ants ( 6), coccinellid beetles ( 7), chrysopid larvae ( 8), and parasitoid wasps ( 9). It acquires the toxins from its larval food plants (species of Crotalaria family Fabaceae), retains them through metamorphosis, and as an adult, transmits them in part to the eggs ( 3). Utetheisa derives protection from pyrrolizidine alkaloids (PAs). To address these questions, we turned to an experimental animal, the arctiid moth, Utetheisa ornatrix (henceforth referred to as Utetheisa), which we have studied for a number of years, both in the field and laboratory. Are the insects themselves affected negatively by possession of the toxins, and are the negative effects discernable and quantifiable? A question of interest is whether insects that put phytotoxins to defensive use incur a cost by doing so. They absorb the compounds from the gut and incorporate them systemically, with the result that they are protected against predation ( 1, 2). Many insects sequester toxic secondary metabolites from their food plants. ![]()
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