Choosing between good and better: optimal oviposition drives host plant selection when parents and offspring agree on best resources

Abstract

Insect preferences for particular plant species might be subjected to trade-o V s among several selective forces. Here, we evaluated, through laboratory and W eld experiments, the feeding and ovipositing preferences of the polyphagous leafminer Liriomyza huidobrensis (Diptera: Agromyzidae) in relation to adult and o V spring performance and enemy-free space. Female leafminers preferred laying their eggs on Vicia faba (Fabaceae) over Beta vulgaris var. cicla (Chenopodiaceae), in both laboratory and W eld choice experiments, although no oviposition preference was observed in no-choice tests. Females fed more often on B. v. var. cicla (no-choice test) or showed no feeding prefer- ence (choice test), even when their realized fecundity was remarkably higher on V. faba. O V spring developed faster, tended to survive better, and attained bigger adult size on the preferred host plant. Also, a W eld experiment showed higher overall parasitism rates for leafminers developing on B. v. var. cicla, with a nonsigni W cant similar tendency in W eld surveys. According to these results, host plant selection by L. huidobrensis appears to be driven mainly by variation in host quality. Moreover, the consistent oviposition choices for the best host and the labile feeding preferences observed here, suggest that host plant selection might be driven by maximization of o V spring W tness even without a con X ict of interest between parents and o V spring. Overall, these results highlight the complexity of decisions performed by phy- tophagous insects regarding their host plants, and the impor- tance of simultaneous evaluation of the various driving forces involved, in order to unravel the adaptive signi W cance of female choices.