A Big Bluet damselfly (Enallagma durum) was spotted during a photowalk with Michael Powell along Deephole Point Road at Occoquan Bay National Wildlife Refuge (OBNWR), Prince William County, Virginia USA.
This individual — one of hundreds, if not thousands we saw while hunting for a rare to uncommon species of dragonfly — is a male, as indicated by his blue and black coloration and terminal appendages.
Ideal habitat for Big Bluet is as follows.
Habitat Large sandy lakes and lower reaches of rivers, even extending into brackish estuaries. Source Credit: Paulson, Dennis (2011-12-19). Dragonflies and Damselflies of the East (Princeton Field Guides) (Kindle Locations 2156-2157). Princeton University Press. Kindle Edition.
Think large, tidal rivers and bays. I have observed E. durum at Dyke Marsh Wildlife Preserve, Accotink Bay Wildlife Refuge, and Occoquan Bay National Wildlife Refuge.
Related Resources: Excellent digital scans created by Gayle and Jeanelle Strickland. Click on the button labeled “Download file” in order to view/save a full-size version of the graphics.
Sidebar: Scientific Classification of Damselflies
The following concise explanation of the scientific classification of damselflies is provided to help the reader understand where the genus Enallagma (American Bluets) fits into the bigger picture of the Order Odonata, Suborder Zygoptera (Damselflies).
There are four families of damselflies in the United States of America (USA), although only three families occur in the mid-Atlantic USA: Broad-winged damselflies; Narrow-winged damselflies (a.k.a., Pond Damselflies); and Spreadwing damselflies.
- Family Calopterygidae – Broad-winged Damselflies
- Family Coenagrionidae – Narrow-winged Damselflies
- Family Lestidae – Spreadwings
Note: Family Platystictidae (Shadowdamsels) is the fourth family of damselflies in the USA. Desert Shadowdamsel (Palaemnema domina) is the only member of this family. P. domina is rare, known to occur only in Arizona in the southwestern United States.
1. Family Calopterygidae is comprised of two genera.
2. Family Coenagrionidae is comprised of 14 genera. Three genera are common in Northern Virginia: Argia (Dancers); Enallagma (American Bluets); and Ischnura (Forktails).
- Argia (e.g., Blue-fronted Dancer, Blue-tipped Dancer, Variable Dancer)
- Enallagma (e.g., Big Bluet, Familiar Bluet, Orange Bluet, Stream Bluet)
- Ischnura (e.g., Eastern Forktail, Fragile Forktail, Rambur’s Forktail)
3. Family Lestidae is comprised of two genera.
- Archilestes (e.g., Great Spreadwing)
- Lestes (e.g., Slender Spreadwing, Southern Spreadwing, Swamp Spreadwing)
There are relatively few genera of Broad-winged Damselflies and Spreadwing Damselflies. In contrast, there are many more genera and species of Narrow-winged Damselflies — more species, including many that look similar, makes this family the most challenging to learn!
Related Resource: “The Odonata of North America” is a complete list of both scientific names and common names for damselflies and dragonflies, maintained by the Dragonfly Society of the Americas.
An interactive version of the same species list is available from the Odonata Central Web site. The master list can be filtered in many ways. Location is perhaps the most useful filter.
For example, my good friend Mike Boatwright lives in Amherst County, Virginia USA. Click on the blue button labeled “Filter Results.” Then click the down arrow in the Location field, enter “Amherst” and select the complete location name that appears in a list of available options; click the “Apply Filtering” button. You should see a list of 97 species of odonates reported to occur in Amherst County, including 10 species in the genus Enallagma. Notice that Big Bluet isn’t on the list, although there are several species of Enallagma that aren’t found where I live in Fairfax County, Virginia USA.
Copyright © 2020 Walter Sanford. All rights reserved.
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