Thursday, April 26, 2012

Apr 24, 2012: Erv's Field Notes #32

Male Eastern Forktail (Erv Klaas)

Tuesday, April 24, 2012. 4-5 PM. Beautiful sunny day, no wind. Temperature: 80 degrees F.

I parked in the lot on Harrison Road. From the car, I quickly scanned the pond next to the lot with my binoculars and spotted a Pied-bill Grebe swimming close to shore. In the foreground of my view, I could see several dragonflies flitting about so I walked down the hill to get a closer look. I identified three species of Odonata (the name of the Insect Order to which dragonflies and damselflies belong): one male Common Green Darner, several pairs of Variegated Meadowhawks, and 20 or more Eastern Forktail damselflies. These three species have been around for about a month. The Darner and the Meadowhawk are migratory dragonflies that winter in states along the Gulf Coast.

The Eastern Forktail is around all summer and is active through October depending on temperatures. It may produce more than one generation each season. They are very small and inconspicuous to the naked eye but when viewed through an 8X binocular they are exquisitely beautiful. The male’s thorax is bright green with black stripes and the abdomen is black with a bright blue tip. This is one of the most abundant damselflies in the Park and can be found in low growing vegetation near the water’s edge of the lake and wetlands.

The Variegated Meadowhawks pairs that I observed today were in tandem and laying eggs. When in tandem, the male grasps the female behind the head with a pair of claspers located at the tip of his abdomen. Their wings beat in unison but the female seems to be in control. Several pairs were flying low over the water and every few seconds the female would tap her abdomen on the surface of the water to deposit her eggs. Three different times, a large sunfish leaped out of the water in an unsuccessful attempt to catch the dragonflies. Egg laying continued for the hour that I was at the pond.

Although I only saw a single male Common Green Darner, I have observed their egg laying behavior in previous years and it is quite different from the Meadowhawk. A pair in tandem will alight on a plant that is partially submerged in the water and the female will submerge most of her abdomen in the water. The pair may stay in one place for several minutes before moving on to another plant, presumably to spread the eggs around and not put them “all in one basket.”

Erv Klaas

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