Plant-derived pyrrolizidine alkaloid protects eggs of a moth (Utetheisa ornatrix) against a parasitoid wasp (Trichogramma ostriniae)

Abstract

Pyrrolizidine alkaloid (PA), sequestered by the moth Utetheisa ornatrix from its larval food plant, is transmitted by both males and females to the eggs. Males confer PA on the female by seminal infusion, and females pass this gift, together with PA that they themselves procured as larvae, to the eggs. Here we show that PA protects the eggs against parasitization by the chalcidoid wasp, Trichogramma ostriniae. Eggs laid subsequent to a first mating of an Utetheisa female receive most of their PA from the female. The amount they receive from the male is insufficient to provide for full protection. However, female Utetheisa are promiscuous and therefore likely to receive PA on a cumulative basis from their male partners. chemical defense ͉ parasitism ͉ Arctiidae ͉ Trichogrammatidae

The Cost of Mating: Influences of Life History Traits and Mating Strategies on Lifespan in Two Closely RelatedYponomeutaSpecies

“…These positive effects include compensation for mating with a genetically incompatible, inferior, or infertile male and an increase in genetic variability among the offspring ( [16,17], and references therein). Moreover, substances in the male ejaculate (nuptial gifts) can increase female lifespan [18,19], female fecundity (see [20] for an overview), and offspring fitness [21,22]. Positive effects of the ejaculate act either directly, by providing extra resources for somatic maintenance of females ( [18] and references therein [19,23]), or indirectly, by protecting the female against predators (e.g., the pyrrolizidine alkaloids transferred by male Utetheisa ornatrix [24]).…”

The study of plant specialized metabolism: Challenges and prospects in the genomics era

“…In a particularly complex case, the arctiid moth Utetheisa ornatrix actively takes up PAs from plant sap, and males use the alkaloids to synthesize pheromones that advertise their alkaloid load to females. They transfer accumulated PAs to the female while mating (Campo et al, 2005), and in turn, the female transfers the PAs to the eggs for protection against predators (Eisner and Meinwald, 1987;Bezzerides et al, 2004). The involvement of metabolites in such plant-biotic interactions may also make them mediators of speciation, as suggested in the "escape-and-radiate coevolution" hypothesis (Thompson, 1994).…”

Chemical Defence and Toxins of Plants

“…Furthermore, females of Utethesia ornatrix transmit PAs that have been transmitted by males during copulation to eggs for protection of eggs. 27 Figure 2 Synthetic pathway and activation process of pyrrolizidine alkaloid. [24][25][26] 4.08.1.2.1(ii) Nonprotein amino acids Nonprotein amino acids are amino acids other than the 20 amino acids incorporated in protein (Figure 3).…”