For this month’s edition of “Insect of the Month” I wanted discuss an insect that is fairly unknown to a lot of people: the Hine’s Emerald Dragonfly (Somatochlora hineana). Dragonflies in general are fascinating in their behaviors, habitat and how their bodies function. Because of this insect’s rarity in particular, even many entomologists don’t know about its unique history and highly specialized life cycle. The more you dive into the world of entomology, the more bizarre creatures you can discover and this will be no exception.
The Hine’s Emerald Dragonfly (HED) has historically been found in the middle of America, from Alabama to Minnesota and every state around the Great Lakes. Today they can only be found in Illinois, Michigan, Missouri and Wisconsin. Through decades of industrial and residential development, many of the wetlands they depend on have been drained. HED and other dragonflies will only lay their young in clean, uncontaminated water, so the degradation of groundwater from pollution has also impacted their numbers.
HED also has some very restrictive conditions in which its young can survive. These insects require calcareous (high in calcium carbonate), spring-fed marshes specifically to lay their young. Adult males will defend an area inside the marsh and wait for females. The females will lay their eggs in the marsh, where they will remain until they hatch the following spring. These newly hatched aquatic nymphs will remain immature for up to 4 years! This is one of the longest immature stages in all of the insect kingdom! Once they do emerge as adults they breed and will only live 4-5 weeks.
Many of you may be asking yourself, “why do I care about dragonflies anyway”. The truth is there are several good reasons why you should care about HED and all dragonflies. First, they are a natural indicator to contaminated water. If you have a pond or marsh on your property that normally has dragonflies and you notice it doesn’t, its time to get a water sample. Secondly, they eat other aquatic larvae and insects, which include mosquitoes. Where dragonflies are low, mosquitoes thrive. Lastly, it is our responsibility to be good stewards of the land. We should always be conscious of the impacts we have on the land and water, to include protecting its animals.
Even though the Hine’s Emerald Dragonfly is not native to our area it is a great insect to study and know. We can take the same practices used to protect it, to protect our local dragonflies. Always be careful of our waterways and keep an eye for all the beautiful examples of God’s creation. Be safe out there.