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Assisted migration consists of the introduction of a species to previously inhabited areas or to new suitable regions. Such introductions have been touted as a viable tool for conserving the earth's biodiversity. However, both the likely success of assisted migrations and the impacts on local communities are hotly debated. Empirical data on the local impacts of assisted migration are particularly lacking. We examined the short and long time‐scale effects of herbivory on Lonicera involucrata (Richards) Banks ex. Spreng (Caprifoliaceae) after an introduction of Euphydryas gillettii Barnes (Lepidoptera: Nymphalidae, Melitaeini) to Gunnison County, Colorado, USA, via an assisted migration in 1977. The plant is the primary larval host plant for the butterfly. We quantified plant seed production, plant survival, and population stage structure in two sets of observational experiments. We found that herbivory by E. gillettii increased L. involucrata reproduction on an annual time scale, independent of plant size and local microhabitat characteristics. Over the time since the butterfly's introduction, herbivory by E. gillettii resulted in a plant population structure biased toward smaller plants in the butterfly introduction and satellite sites compared with sites without the butterfly. Our results highlight the importance of studying the effects of assisted migrations on native populations at different temporal scales. As assisted migration becomes an indispensable tool for species conservation, our work adds to the understanding of the multi‐trophic impacts of assisted introductions on local populations and communities. [ABSTRACT FROM AUTHOR]

The evolution of flight in an early winged insect ancestral lineage is recognized as a key adaptation explaining the unparalleled success and diversification of insects. Subsequent transitions and modifications to flight machinery, including secondary reductions and losses, also play a central role in shaping the impacts of insects on broadscale geographic and ecological processes and patterns in the present and future. Given the importance of insect flight, there has been a centuries-long history of research and debate on the evolutionary origins and biological mechanisms of flight. Here, we revisit this history from an interdisciplinary perspective, discussing recent discoveries regarding the developmental origins, physiology, biomechanics, and neurobiology and sensory control of flight in a diverse set of insect models. We also identify major outstanding questions yet to be addressed and provide recommendations for overcoming current methodological challenges faced when studying insect flight, which will allow the field to continue to move forward in new and exciting directions. By integrating mechanistic work into ecological and evolutionary contexts, we hope that this synthesis promotes and stimulates new interdisciplinary research efforts necessary to close the many existing gaps about the causes and consequences of insect flight evolution., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology.)

Peak metabolic rate reflects maximal performance and may have direct fitness consequences, whereas resting metabolic rate (RMR) represents the maintenance cost of the whole animal. These traits may be linked, which has significant implications for the evolution of both traits. In vertebrates, a positive correlation between resting metabolic rate and aerobic capacity has been proposed to explain the origin of endothermy. However, as studies on the relationship between resting metabolic rate and aerobic capacity have focused on vertebrates, we know much less about these traits in ectothermic insects. I measured RMR in the Glanville fritillary butterfly (Melitaea cinxia) using two configurations: one optimized for measuring flight metabolic rate, the other optimized for resting metabolic rate. The relationship between RMR and body mass was similar for the two configurations. Body mass explained 82% of the variation in RMR when it was measured using the "flight" configuration at 32°C, and 91% when using the "rest" configuration at 23°C. The Q10 coefficient calculated based on the two RMR measurements was 2.8. Mass-independent RMR was positively correlated between measurements obtained using the two instrument configurations. However, neither measure of RMR was correlated with peak metabolic rate, which indicates that RMR cannot be used as a surrogate measure for aerobic capacity in the Glanville fritillary. Ectothermic insects may be able to combine high metabolic capacity with no apparent increase in maintenance cost. Even though RMR is among the most frequently measured physiological variables, it may have limited predictive power when it comes to questions related to activity or aerobic capacity, or in the case of butterflies, flight performance., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology.)

High peak metabolic rates may provide a performance advantage, but it may also entail a physiological cost. A long-held assumption is that high mass-specific energy expenditure is associated with short lifespan. To examine the relationship between energy expenditure and lifespan we asked two questions. First, do individuals have a consistent rate of metabolism throughout their life? Second, is metabolic rate correlated with lifespan? We analysed the repeatability of measurements of resting (RMR) and peak flight metabolic rate (MR(peak)) throughout the life of the Glanville fritillary butterfly (Melitaea cinxia). Measurements of MR(peak) showed significant repeatability. Senescence occurred only shortly before death. RMR showed a U-shaped relationship with age and very low repeatability. Intraspecific association between metabolic rates and lifespan was tested under three conditions: in the laboratory, under field conditions and in a laboratory experiment with repeated flight treatments. There was a significant correlation between MR(peak) and lifespan in all three experiments, but the correlation was positive, not negative. RMR was not correlated with lifespan. Both MR(peak) and lifespan may reflect physiological condition and therefore be positively correlated. Individuals with a large resource pool may be able to invest in mechanisms that slow down ageing. Individuals with high metabolic capacity may also possess adaptations against ageing. Molecular polymorphism in the gene phosphoglucose isomerase (Pgi) was significantly associated with both MR(peak) and lifespan, and may have coevolved with defence mechanisms against senescence. Generalisations such as 'live fast, die young' may be too simple to explain the complex processes affecting ageing and lifespan.