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The Skillet Clubtail Dragonfly: What you don’t know

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Fig. 1. Skillet Clubtail dragonfly adult; notice the distinctive “skillet” on tail. Photo Credit: David Marvin. Used under a Creative Commons BY-NC-ND 2.0 licence. 

By Melody McLean

What if I told you that as a New Brunswicker, there are animals in danger of going extinct in your own backyard? Saying that, you’re probably thinking of a cute, fuzzy, little animal with big, sad eyes being displaced from its home.  Well, that’s not what I’m referring to. I’m talking about the Skillet Clubtail Dragonfly (Gomphus ventricosus), belonging to the insect order Odonata. This dragonfly currently has no status under the Species at Risk Act (SARA), but was the only arthropod classified in the 2010 COSEWIC (Committee On the Status of Endangered Wildlife In Canada) report as being endangered. Simply put, if we don’t do something, they could become extirpated[i] from Canada or even extinct.  When we hear about insects in our province, we often associate them with being pests, like spruce budworm, aphids, or disease spreading agents like mosquitos. But what we don’t often realize is that not all animals at risk of extinction are cute and fluffy. I’m here to shed some light on an underdog of the animal world, who could use a little help from us.

Insects-we can’t live with them; we can’t live without them.

  What you may not know is just how thankful we (myself included) should be for insects. They clean up after us, help to provide us with rich soil for our gardens, indirectly provide us with fresh food thanks to their pollination efforts; some, like dragonflies, even keep other insects from bugging us¾like our own personal pest control.

 

The Skillet Clubtail dragonfly is strikingly beautiful, with green, yellow, black and brown markings running along its thorax and abdomen; transparent wings; big dark green eyes; and a distinctive circular flare, resembling a skillet, at the tip of its tail (Fig. 1).

The Biology behind the Insect

The Skillet Clubtail’s  life cycle and biology is very similar to that of other dragonflies. The female lays her eggs by dipping her abdomen into the water to release them. Growing and developing, the shallowly burrowed nymphs take at least 2 years (possibly more) to develop before emerging. If conditions are right, usually in the latter 2 weeks of June, the dragonfly nymphs will find a “settle point” where the water is calm; they’ll climb up onto nearby vegetation to emerge synchronously[ii] as adults. Although the nymphs spend the majority of their lives in the water, the adults spend most of their lives around brush, fields, bogs and in the nearby canopy to forage for other insects.

Home of the Skillet Clubtail

 This stunning dragonfly is restricted to North America. In Canada, it is currently found only in a few select places along the Saint John River, specifically in the Fredericton region of New Brunswick.  Over 60 years ago, the Skillet Clubtail could be found in a few other locations in Canada, including Ontario, Nova Scotia and Quebec. But since there have been no recent sightings there, New Brunswick may be the last known Canadian location. The United States is running into similar problems with this insect too.  It was once found in Pennsylvania and New York but is likely extirpated from both of those areas. The U.S. range extends along the Red River Basin, running from Mississippi, Tennessee, Minnesota, to the northeastern limit in New Hampshire and Maine.

Habitat: Very Important

 This insect is in need of a specific and rare habitat type: a clean, large, slowly running body of water, with fine sediments and substrate, such as clay, silt, or sand, with nearby forested areas for cover. Many of these habitats are only found when the waters run through an area of rich soils, at a low gradient[iii].

99 Problems

 This is where problems arise, as the Skillet Clubtail’s habitat is often prime agricultural land, where possible pollution in the river can occur, and nutrient run-off becomes a concern. Keep in mind, agriculture runoff from fertilizers, pesticides, and herbicides, are not the only culprits behind river pollution. Accidental and illegal dumping, and everyday toxins such as oil, grease, road salt, contaminants from vehicle exhaust, lawn and garden chemicals, and other harmful substances, all have a tendency to wash off lawns and roadways down to rivers and waterways. This is especially relevant here in Fredericton as the Saint John River is considered to have “marginal” water quality. As this city is literally built on a hill, all that urban runoff must go somewhere.

Although pollution is likely a major factor to this species decline, there is also the problem of sea level rise. As the sea level rises, saline water travels further up stream into the rivers, changing the chemistry of the water. This is likely to impact freshwater aquatic wildlife, as most aquatic species cannot adapt to such rapid change in their habitat. Because the farthest population is just 5 km away from the saline water limit, this is a real possibility. It’s been discussed that the Skillet Clubtail populations further upstream on the Canaan River and Salmon River could be safe from saline influence. However it has also been speculated that the main Saint John River population acts as a metapopulation, supporting the other two populations by providing immigrating individuals to them.

It’s good to note that this species needs the surrounding forest, included in its habitat. Even though mass cuttings of forests in these locations are unlikely to happen right now, we should still keep in mind deforestation has the potential to affect not only the Skillet Clubtail dragonfly, but many other species as well.

 

Why should you care?

 

Maybe you’ve gotten through this whole article and decided that you don’t care about the Skillet Clubtail Dragonfly. That’s fine. But think of it this way: the things that are likely affecting this particular dragonfly should be of broader concern to us. Chemical runoff, deforestation, general pollution and rise in sea level don’t just affect this one dragonfly species; they affect everything living that comes in contact with them, including us. The best way to finding a solution to a problem is by better understanding it through increasing our knowledge.  Don’t be ignorant of the events happening in your community and environment. Take notice and do something about any detrimental events, like pollution, in your area. Dragonflies and other aquatic insects are great indicators of stream and river health, and not much is known about this particular dragonfly. So if you spot the Skillet Clubtail dragonfly, send your recordings and findings to your local Entomological Society. Many little changes have the potential to lead to one big change.

 

[i]  Extirpated: a species that was once found in an area but is no longer found there. This is different from extinction because you can still find that particular species of animal in other areas of the country or world, therefore not totally extinct just extirpated.

[ii] They all emerge at once over a short period of time.

[iii] Low gradient streams are associated with flattened stream beds, with slow moving water and gradual, less steep slopes of surrounding valley

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