Life of the Damselfly: the benthic with respiratory wing pads
The damselfly is a fascinating benthic macroinvertebrate that will undergo incomplete metamorphosis involving the following phases: the egg, the nymphal stage, and the adult stage. The life cycle of a damselfly usually lasts one year and most of this time the damselfly is in the nymphal stage. Today we will explore what happens after the damselfly leaves the safety and familiarity of the water? And how does the damselfly transform into its adult form? To explore these questions, we’ll start at the very beginning-- when the damselfly eggs are first laid.
When damselflies mate, the male will attach the back of his abdomen to the female’s head and the mating pairs will fly in tandem until the female is able to go and lay her eggs in aquatic emergent and submergent vegetation, just above the water line or at times directly on the water. If mating occurs in the spring, after 1-3 weeks the eggs hatch releasing the nymphs, however if mating occurs in late summer, the eggs may overwinter before they hatch.
Once in the nymphal stage, damselflies will breathe through three leaf-like gills and begin preying on fish-fry, tadpoles, water beetles, and smaller nymphs. Depending on the species and various environmental conditions, the stage can last anywhere from 1 to 3 years. Throughout this time, the damselfly may shed its skin anywhere from 5 to 15 times, going through instar developments before becoming ready to emerge into the adult form.
Now ready to become an adult, the damselfly will crawl out of the water and moult or shed its exoskeleton one final time and transform into an adult damselfly. Adults have a lifespan of a few weeks to a few months in this stage. Respiration at this stage is also occurring through the damselflies wing pads!
Fun Fact: Some damselflies that are now extinct were nearly one metre in length!
Fun Fact: Adults are able to devour their prey while holding it in their legs as they fly.
Fun Fact: A distinction can be made between dragonfly and damselfly larvae by looking at the abdomen. While dragonflies have an abdomen ending in five points, damselfly larvae have abdomens ending in 3 leaf-like gills, which are fragile and sometimes broken off or lost. Another way to distinguish the two is that dragonflies hold their wings horizontally at rest while most damselflies hold their wings together above the body.
Interested in learning more about benthic macroinvertebrates and how they can be used to measure the health of rivers and streams? Be sure to follow EcoSpark’s social media to stay updated on our Changing Currents program and our other citizen science and environmental education programs.
References
Jee and Rani Nature Photography. (2016). Wiki Media. Retrieved from: https://en.wikipedia.org/wiki/Damselfly#/media/File:Ceriagrion_cerinorubellum-Kadavoor-2016-04-11-002.jpg
Katatrepsis: Science, skepticism and dragonflies. (2011). Dragonflies vs. damselflies. Retrieved from: https://katatrepsis.com/2011/08/14/dragonflies-vs-damselflies/
Carina holds a Bachelor of Honors in Environmental Studies and a diploma in Ecosystem Technology, both of which developed her interest in using geographic information systems to communicate about complex issues, such as climate change. In her role as Lead Environmental Educator, Carina designs geospatial education tools for EcoSpark’s citizen science programs. When outdoors in the field, you will often find her streamside identifying aquatic critters, communicating her enthusiasm for the outdoors, and demonstrating her dedication to stewardship practices with youth and adults throughout the GTA.