Diamesa mendotae (Diptera: Chironomidae) Demonstrate Predictable Behavior Patterns Associated with Aging and Mortality

Chironomidae (Diptera) are one of the most abundant aquatic insects in freshwater habitats and play key roles in aquatic ecosystems. Many studies have assessed chironomid longevity under varying conditions to estimate potential consequences of climate change on longevity. However, these studies did not account for behavioral changes that may affect the ability of chironomids to find a mate or return to the water for oviposition. Longevity estimates may therefore underestimate the effects of climate change on chironomids by neglecting behavior-related fitness losses. To better understand how chironomid behaviors relate to survivorship, we used previously identified behaviors to determine how behavior patterns changed as the chironomid Diamesa mendotae aged. We found that D. mendotae exhibited age-related behaviors that correlated with a decrease in mobility over time. Additionally, behaviors performed early post-collection in D. mendotae adult lifespans were predictive of total chironomid longevity. These findings will help improve estimates of chironomid longevity and our understanding of age-related behaviors in other invertebrates. Improved methods for determining longevity and age-specific fitness-linked behaviors will allow us to better understand climate change’s impacts on aquatic insect survival and reproduction, which has broad ramifications for the aquatic ecosystems where they are abundant.