Diversity and Abundance of Dragonflies and Damselflies in Tampa Bay, Florida

Abstract

Little is known about the community of dragonflies and damselflies in Tampa Bay, Florida, USA. To address this gap, we conducted 2 longitudinal surveys of adult odonates in a natural floodplain of the Hillsborough River in 2013 and 2017. Along with abundance and species diversity, we also measured intraspecific variation in body size, sexual dimorphism, wing-cell asymmetry, and water mite ectoparasitism. Our first weekly survey from Oct 2013 to Oct 2014 sampled 327 adults (230 female, 97 male) from 8 dragonfly species, with the eastern pondhawk (Erythemis simplicicollis Say; Odonata: Libellulidae) representing 79% of captures, followed by the second most abundant (14%), the Florida non-native and neotropical hyacinth glider (Miathyria marcella Selys; Odonata: Libellulidae). Our second weekly survey from Sept to Dec 2017, which focused on both damselflies and dragonflies and captured 205 adults from 8 species, with the fragile forktail (Ischnura posita Hagen; Odonata: Coenagrionidae) being the most abundant with 70% of captures. Female-biased sexual size dimorphism was found in both E. simplicicollis and I. posita; however, both sexes were equally variable in size and symmetric in a meristic trait. Female and male M. marcella were equally variable, monomorphic, and symmetric. Combing symmetry data from each sex, only I. posita damselflies were asymmetric overall. Finally, we did not observe any parasitism by larval water mites in either survey. We aim to continue surveys to track seasonal and climate-driven changes in dragonfly diversity and phenology in this region.