Effects of Zebra Mussel Colonization on Dragonfly Larvae Burying Behavior
Zebra mussels (Dreissena polymorpha) invaded North American aquatic ecosystems in 1986, altering ecological communities and harming human infrastructure. Zebra mussels have been found attached to dragonfly larvae, decreasing the likelihood of successful emergence as adults. This study assesses negative impacts zebra mussel colonization has on dragonfly larvae by testing the effects of colonization on dragonfly burying behavior. Macromia illinoiensis larvae and zebra mussels were tested at Douglas Lake, Michigan in July and August 2009. Weather and water temperature affected uncolonized burial time, but not uncolonized burial depth. Uncolonized burial time, head width, and body area predicted which individual dragonflies got colonized. Once individuals were colonized, their burial depth was impaired, which could lead to early mortality. Because dragonflies link aquatic and terrestrial ecosystems, increased early mortality of dragonflies could cause cascading effects across ecosystems.