A novel trade-off of insect diapause affecting a sequestered chemical defense.
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-offs involving sequestered chemical defense. We examined the aristolochic acid defenses of diapausing and non-diapausing pipevine swallowtail butterflies, Battus philenor. Pipevine swallowtail larvae acquire these chemical defenses from their host plants. Butterflies that emerge following pupal diapause have significantly less fat, a female fitness correlate, compared to those that do not diapause. However, butterflies emerging from diapaused pupae are more chemically defended compared to those that have not undergone diapause. Furthermore, non-diapausing butterflies are confronted with older, lower quality host plants on which to oviposit. Thus, a trade-off exists where butterflies 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 benefit of greater chemical defense and plentiful larval food resources.
Fordyce
James A
JA
Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN 37996, USA. jfordyce@utk.edu
Nice
Chris C
CC
Shapiro
Arthur M
AM
D000222:Adaptation, Physiological / Q000502:physiology*; D000704:Analysis of Variance; D000818:Animals; D030022:Aristolochia / Q000502:physiology; D034341:Aristolochic Acids / Q000032:analysis*; D001823:Body Composition / Q000502:physiology; D002080:Butterflies / Q000737:chemistry* / Q000502:physiology*; D002140:California; D004734:Energy Metabolism / Q000502:physiology; D007814:Larva / Q000737:chemistry / Q000502:physiology
D034341:Aristolochic Acids; C000228:aristolochic acid I