Plant Animal Interactions

Diapause allows insects to temporally avoid conditions that are unfavorable for development and reproduction. However, diapause may incur a cost in the form of reduced metabolic energy reserves, reduced potential fecundity, and missed reproductive opportunities. This study investigated a hitherto ignored consequence of diapause: trade-oVs involving sequestered chemical defense. We examined the aristolochic acid defenses of diapausing and non-diapausing pipevine swallowtail butterXies, Battus philenor. Pipevine swallowtail larvae acquire these chemical defenses from their host plants. ButterXies that emerge following pupal diapause have signiWcantly less fat, a female Wtness correlate, compared to those that do not diapause. However, butterXies emerging from diapaused pupae are more chemically defended compared to those that have not undergone diapause. Furthermore, non-diapausing butterXies are confronted with older, lower quality host plants on which to oviposit. Thus, a trade-oV exists where butterXies may have greater energy reserves at the cost of less chemical defense and sub-optimal food resources for their larvae, or have substantially less energetic reserves with the beneWt of greater chemical defense and plentiful larval food resources.