Effects of environmental warming during early life history on libellulid odonates

Abstract

Climate warming affects ectotherms globally, yet we know little regarding the variability in species' responses to warming, particularly in early life stages. Additionally, intraspecific variation in response to warming is understudied but may determine species' resilience to warming. To assess how temperature affects egg development rate in co-occurring dragonfly species, we manipulated temperature (range: 22-31°C) and measured time to hatching. Warming decreased egg development time across all species, indicating that while climate warming will advance hatching phenology, maintained synchrony in hatching order will likely not affect species interactions. Our second experiment examined early life-history responses to warming in the dot-tailed whiteface (Leucorrhinia intacta (Hagen, 1861)) dragonfly. We measured time to hatching, hatchling size, growth rate, and survival at four temperatures (23-30°C), including a treatment with increased thermal variation. Warming resulted in smaller hatchlings with increased growth and mortality rates, whereas higher thermal variation did not have effects different from those of warming alone. We observed significant intraspecific variation in the responses to warming in both egg development time and hatchling size and this variation was correlated with date of oviposition. High levels of intraspecific variation may be important in buffering populations from the effects of climate warming.Key words: body size, climate change, development, ectotherm, life history, Odonata, survival. Résumé :Si le réchauffement climatique a une incidence sur les organismes ectothermes en général, les connaissances sur la variabilité des réactions des espèces au réchauffement sont limitées, particulièrement pour les premières étapes du cycle de vie. Les variations intraspécifiques de la réaction au réchauffement sont également sous-étudiées même si elles pourraient déter-miner la résilience des espèces au réchauffement. Pour évaluer l'influence de la température sur le taux de développement des oeufs chez des espèces de libellules cooccurrentes, nous avons manipulé la température (fourchette : 22 à 31°C) et mesuré la durée d'incubation. Le réchauffement réduisait la durée de développement des oeufs pour toutes les espèces, ce qui indique que, si le réchauffement climatique accélérera la phénologie de l'éclosion, le maintien du synchronisme de l'ordre d'éclosion n'aura vraisemblablement pas d'incidence sur les interactions entre espèces. Notre deuxième expérience se penchait sur les réactions au réchauffement durant les premières étapes du cycle de vie de la leucorrhine mouchetée (Leucorrhinia intacta (Hagen, 1861)). Nous avons mesuré la durée d'incubation, la taille des bébés nouvellement éclos, le taux de croissance et la survie à quatre températures (de 23 à 30°C), incluant un traitement comprenant des variations de température accrues. Le réchauffement produisait des bébés plus petits présentant des taux de croissance et de mortalité accrus, alors que l'augmentation des variations de...

Size‐mediated priority and temperature effects on intra‐cohort competition and cannibalism in a damselfly

“…Increased temperature below the thermal optimum should increase growth and feeding rates in ectothermic organisms (Dell, Pawar, & Savage, ; Frances, Moon, & McCauley, ; Gresens, Cothran, & Thorp, ) and result in stronger priority effects (Grainger et al., ). Interestingly, our results did not support this prediction since the priority effects at the high temperature did not have stronger negative effects on life‐history traits than did the low temperature, that is we found no statistical interaction between treatment and temperature ( t test and Table ).…”

Phenology of the regionally Critically Endangered dragonfly Urothemis edwardsii in the National Park of El Kala, Northeast of Algeria

“…The year 2018 was drier but slightly cooler than 2019. The weather has an important influence on the life history of odonates (Hassall & Thompson, 2008;Frances et al, 2017;McCauley et al, 2018). Studies have shown experimentally that odonate larvae grow faster and emerge earlier under warmer conditions (Lutz, 1974;Pickup & Thompson, 1990), which explains the phenological shift that has been recorded during the past decades (Hassall et al, 2007;Dingemanse & Kalkman, 2008).…”

Ecological Factors and the Distribution of Adult Odonata in Puerto Rico

“…Temperature is known to affect many aspects of the life history of Odonata (see review by Hassall and Thompson 2008). For example, increased temperature has been shown to affect egg development (Frances et al 2017), larval growth rates (Pritchard et al 2000, Suhling et al 2015, Frances et al 2017), larval survival (McCauley et al 2015, and sexual coloration (Moore et al 2018). As a consequence, the distribution of dragonflies and damselflies across the landscape may be determined by the thermal heterogeneity of the habitat and the sensitivity of the insect to temperature.…”