Beskrivning
Declining butterfly abundance over recent decades is associated with habitat loss and increasingly warmer springs. Warmer temperatures pose a problem for capital breeders, especially those species that enter diapause as a pupa or adult, since a higher metabolic rate depletes lipid store reserves used for egg production at a greater rate. While the adults can collect additional carbohydrate and amino acid resources from nectar plants upon emergence it remains unclear to what extent access to flowering plants can limit the predicted loss in potential fecundity. To investigate this relationship, we undertook a three-way factorial experiment on Pieris napi, a model butterfly species that overwinters as a pupa, to evaluate the consequences for fitness of access to sugar solution (ad libitum vs. water control) for pupae exposed to varying post-diapause temperatures (6 vs. 2 oC) and duration times (12 vs. 6 weeks). We found a that a warmer and longer post-diapause time significantly increased the proportion of body mass lost between initial pupation of adult emergence. This proportional loss was found to limit individual fecundity of females, and was equal in effect size to the influence of body mass itself. However, since 1) access to sugar solution had such a strong effect on lifespan and rate of egg laying and 2) warmer spring temperatures increased rate of egg laying during the first week, the consequences of a loss in potential fecundity had limited impact on individual fitness. We support our empirical findings with a structural equation model to integrate both the direct and indirect effects of these treatments on fitness. We conclude that the greatest risk to fitness of a warmer spring may arise from a potential phenological mismatch in emergence time and nectar plant flowering rather than the costs of greater resource depletion during the post-diapause quiescence period.| Period | 2023 sep. 14 |
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| Evenemangstitel | GfÖ Annual Meeting 2023 - 52nd Annual Meeting of the Ecological Society of Germany, Austria and Switzerland: The Future of Biodiversity – overcoming barriers of taxa, realms and scales |
| Typ av evenemang | Konferens |
| Konferensnummer | 52 |
| Plats | Leipzig, Tyskland, SachsenVisa på karta |