Black Spreadwing - Lestes stultus

Damselflies are tough for a beginner like me, as the difference in the species are often subtle. Identification best performed by examination of a specimen "in hand", but sometimes a digi-scoped view gets me close enough to see some subtle features.

Most damselfly species rest with their wings folded near the body, but the Spreadwings (family Lestidae) usually perch or hang with wings in an open position. Here is what I believe is a male Black Spreadwing, Lestes stultus, one of many seen at Nagasawa Community Park in Santa Rosa, California. Photos are from a visit on May 10, 2016.

The male above has started to briefly fold the wings. The sexual appendages at the end of the abdomen are curved inward, with the cerci above framing a window showing the the club-shaped paraprocts below. Here the paraprocts are reflecting white, but in fact are black. Note the black panel near the ends of the wings, the pterostigma, here with a narrow white border.

 

This was the only time I saw this spreadwing with the wings folded, albeit briefly. The head and thorax have a hint of purple iridescence.

A crop of another view shows a bit more detail in the appendages:

Many of the 20+ Black Spreadwings gathered near a small ponded area in the center of the swale, most either in tandem or in the wheel position, as here. The abdomen segments near the end of the male are flexed sharply forward, allowing him to grasp the female just behind the head in an area that I believe is called the prothorax. The female's entire abdomen is curled forward to complete the wheel (or "ring"), allowing her to receive the sperm stored in secondary genitalia of the male on the undersurface of segment 2.

Cropped view of the male grasping the female, showing how the appendages have spread apart to firmly grasp the prothorax.

Black Spreadwing - Lestes stuctus

The Black Spreadwings here were seen with Leslie Flint on a trip to Nagasawa Park in Santa Rosa, June 9, 2014. We watched about a dozen males nervously flitting about in a moist meadow near the parking lot.  At times they perched to give a decent view, hanging from grass with abdomens downward. The male is dark on the top of the abdomen, often showing a bronzy sheen, especially when younger, as seen here.

Lower parts of the abdomen are light blue, and the eyes are bi-colored blue.

Better photos might show that the dark pterostigma ("wing spot") has white color at the ends. This was my very first spreadwing damsel, so it was an exciting day. The Emerald Spreadwing, found at higher elevations, is similar, but with an emerald sheen. The experts think the Black and Emerald may be subspecies, and could be lumped together in the future.

Taxonomy:

Order: Odonata. The Dragonflies, including the Damselflies. Over 5,000 species worldwide.

Suborder:  Anisoptera ("unequal wings") - The Dragonflies. Bigger, thicker bodied, wings held spread apart, eyes large and often touching at midline.

Suborder: Zygoptera ("equal wings") - The Damselfies. Smaller, wings usually held folded, eyes smaller and separated. 41 species of damsels are found in California, but that will likely change in the future as we get warmer.

Family: Lestidae - The Spreadwing Damsels. As their name implies, the spreadwings usually keep their wings spread when perched, except at night or when being harassed. They tend to be larger than other damsels. 19 spreadwing species are found in the U.S., with 7 species documented in California. Worldwide there are 84 spreadwing species.

Genus: Lestes - The Pond Spreadwings. 5 species in California. The other spreadwings here are 2 species of Stream Spreadwings, in the genus Archilestes.

Species: Lestes stuctus - The Black Spreadwing. Range limited to California and Southern Oregon.