I was really excited on Saturday to spot this colorful female Swamp Darner dragonfly (Epiaeschna heros) depositing her eggs into a rotten log at Prince William Forest Park. Some female dragonflies (like this Swamp Darner) and all female damselflies have well-developed ovipositors at the tip of their abdomens that they use to insert their eggs into plant tissues at or below the water level. The first photo gives you a really good look at the Swamp Darner’s spike-like ovipositor in a raised position and the other shots show the ovipositor partially inserted into the log.
An alternative method for laying eggs is used by most dragonfly species. Rather than placing eggs in specific locations like the Swamp Darner, many female dragonflies lay their eggs in clusters directly onto the surface of the water or onto the mud along the water’s edge by tipping their abdomens multiple times against the water in different spots.
This whole process is fascinating to me and I have provided a rather simplified explanation of these different strategies for propagation of the dragonfly species. If you want to learn a bit more, I recommend an article by the Slater Museum of Natural History entitled Odonate Oviposition. Despite its scientific-sounding title, the article is quite easy to read and understand.
© Michael Q. Powell. All rights reserved.
