3 research outputs found
Multidimensional plasticity in the Glanville fritillary butterfly: larval performance is temperature, host and family specific
Variation in environmental conditions during development can lead to changes in life-history traits with long-lasting effects. Here, we study how variation in temperature and host plant (i.e. the consequences of potential maternal oviposition choices) affects a suite of life-history traits in pre-diapause larvae of the Glanville fritillary butterfly. We focus on offspring survival, larval growth rates and relative fat reserves, and pay specific attention to intraspecific variation in the responses (G × E × E). Globally, thermal performance and survival curves varied between diets of two host plants, suggesting that host modifies the temperature impact, or vice versa. Additionally, we show that the relative fat content has a host-dependent, discontinuous response to developmental temperature. This implies that a potential switch in resource allocation, from more investment in growth at lower temperatures to storage at higher temperatures, is dependent on the larval diet. Interestingly, a large proportion of the variance in larval performance is explained by differences among families, or interactions with this variable. Finally, we demonstrate that these family-specific responses to the host plant remain largely consistent across thermal environments. Together, the results of our study underscore the importance of paying attention to intraspecific trait variation in the field of evolutionary ecology.Peer reviewe
Thermal plasticity in development and diapause strategy in a temperate butterfly across a latitudinal gradient
Trade-offs among traits are central to life-history theory and often closely linked to an organism's fitness. Understanding how these trade-offs vary among populations and across environments is therefore important to more accurately predict species' responses to future climate change. However, the extent to which responses vary across populations remains unknown because few studies investigate intraspecific differences.We performed a full-factorial split-brood common garden experiment to test how variation in rearing temperature affects developmental timing and other traits important for survival during diapause in the Glanville fritillary butterfly (Melitaea cinxia). Pre-diapause larvae originating from four regions across a latitudinal cline across Europe were reared at four temperatures (25, 28, 31 and 34 degrees C), and we used a reaction norm approach to test for evidence of genetic differentiation and variation in developmental plasticity across regions.We found clear signs of genetic differentiation in multiple developmental traits, as well as differences in developmental plasticity. Northern larvae entered diapause in the fourth instar when the temperatures were low, whereas southern larvae did so in the fifth instar. As a result, development time is canalized with regards to temperature in northern larvae: due to entering diapause one stage earlier, they develop fast even in the cold, whereas southern larvae always develop slower, especially at low temperatures. As a trade-off, northern larvae have a lower body mass when reared at cooler temperatures compared to southern larvae, and they show increased plasticity in diapause mass. No clear clinal patterns were found in relative fat content.Our results show that trade-offs between body size, development time and growth rate can vary within species living across environmental clines, possibly as a consequence of natural selection to local environmental conditions or other genetic constraints. This variation highlights the importance of recognizing the context dependency of relationships between important life-history traits and their interactions with local environments in predicting species' responses to climate change.Read the free Plain Language Summary for this article on the Journal blog.Read the free Plain Language Summary for this article on the Journal blog.imagePeer reviewe