Dragonflies come in a stunning array of colors and patterns. One particularly eye-catching species is the green and black dragonfly. With its vibrant green thorax contrasting against jet black wings, this dragonfly is truly a sight to behold in flight. But what is the specific name for this dazzling insect?
Identifying Features of the Green and Black Dragonfly
The green and black dragonfly belongs to the larger group known as the “clubtail” dragonflies. There are over 30 different clubtail species in North America alone. They get their name from the distinct enlargement at the end of their abdomen, giving them a club-shaped appearance.
Within the clubtails, the green and black dragonfly belongs to the genus Gomphus. Members of this genus can be identified by the following characteristics:
- Green thorax
- Black abdomen with yellow markings
- Bright green face
- Large size – 2.5-3 inches long
The striking color contrast between the metallic green thorax and jet black wings distinguishes this group. The yellow abdominal markings also help confirm Gomphus species identification.
Gomphus Species Names
There are around 10 different dragonfly species in the Gomphus genus in North America. To identify the specific green and black species, we need to look at some subtle distinguishing traits:
| Species | Key Identifying Traits |
|---|---|
| Common sanddragon | Yellow markings on abdominal segments 7-9 |
| Lilypad clubtail | Yellow markings on abdominal segments 8-9 |
| Dragonhunter | Hangs vertically when perched; largest Gomphus species |
| Sable clubtail | All yellow markings fused together into stripe |
| Cobra clubtail | Yellow only on segment 9; swamp-dweller |
| Midland clubtail | Yellow restricted to segment 8 |
| Mustached clubtail | Dense yellow markings on abdomen |
| Rapids clubtail | Yellow on segments 7-9; fast-flowing streams |
| Rusk’s clubtail | Yellow only on segment 8 |
| Harpoon clubtail | Spear-shaped yellow markings on segments 7-9 |
By matching the yellow abdominal markings to these descriptions, we can determine the specific species.
The Green and Black Dragonfly is…
The species that is most consistent with having vibrant green thorax and black wings, along with yellow abdominal markings on segments 7, 8, and 9, is the…
Rapids Clubtail
The Rapids clubtail (Gomphus quadricolor) matches perfectly with the description of the green and black dragonfly in question. It has the archetypal Gomphus genus features of robust green thorax and black wings. Its yellow markings are distinctly present on abdominal segments 7, 8, and 9.
In addition, the habitat preferences of the Rapids clubtail align with its common name – it is most often found around fast-moving streams and rivers. The larvae thrive in highly oxygenated riffle zones.
Distinguishing features of the Rapids clubtail include:
- Green face
- Green thorax with two faint yellow stripes
- Black wings with amber-yellow at the base
- Black abdomen with yellow spear-shaped marks on segments 7, 8, 9
- Yellow marks do not extend to the upper edge of the abdomen
- Yellow on segment 8 is the longest
- Small club at the end of the abdomen
The striking black and green coloration makes the Rapids clubtail one of the most easily identified dragonflies, even in flight. The vibrant contrast likely plays a role in territorial displays.
Habitat and Range
As its name indicates, the Rapids clubtail prefers fast-flowing rocky streams and rivers with riffle-pool structure. It is most common along mountain rivers and tributaries. The larvae develop in areas of these waterways with plentiful cobble substrate.
This species has a wide distribution across much of the United States:
- West coast – California to Washington
- Rocky Mountains – British Columbia to New Mexico
- Midwest – Minnesota to Ohio
- Northeast – Maine to Virginia
Within this broad swath of North America, Rapids clubtails can be found anywhere suitable river habitat exists. Peak emergence is typically late spring to early summer.
Threats and Conservation
Because the Rapids clubtail relies on high quality, free-flowing rivers and streams, it is vulnerable to activities that alter or degrade these habitats. Major threats include:
- Dam construction – impedes water flow and sediment transport
- Channelization – disrupts velocity and substrate
- Polluted runoff – agricultural, industrial, urban sources
- Deforestation of riparian areas
- Invasive species
Many populations are now isolated due to fragmentation of river networks. Conservation efforts for the Rapids clubtail focus on protecting free-flowing river stretches, maintaining natural flow regimes, reducing pollution inputs, and restoring degraded habitats.
This unique green and black dragonfly serves as an indicator of healthy water quality and aquatic ecosystem function. Continued protection of its specialized river habitat will be crucial for the long-term survival of Gomphus quadricolor.
Conclusion
With its striking green and black color pattern, the dragonfly in question can be definitively identified as the Rapids clubtail. This species in the Gomphus genus has a distribution across much of North America wherever suitable riverine habitat exists. However, degradation of water quality and flow threatens many populations. Protecting the integrity of free-flowing rivers will allow this gorgeous dragonfly to continue gracing waterways and delighting observers into the future.
