Erpetogomphus compositus - Sevilleta NWR, Socorro County, New Mexico, 24 July 2007 - dragonflies selectively feeding on colorful prey.

A Web Page by Roy J. Beckemeyer

Last Updated 25 July, 2007

Right and background: A female Erpetogomphus compositus in her prey-seeking perching position on a barbed-wire fence. 

I visited this locality in the early afternoon from noon until about 2:30pm.  The temperature was in 93ºF and the sky was mostly sunny.  The habitat was a dirt road running along an irrigation canal that parallels the Rio Grande River.  Lots of sagebrush.  The only gomphid I saw was Erpetogomphus compositus.  There were some males perched along the canal exhibiting territorial behavior.  There were also individuals in the vegetation along the road that were obviously feeding.  Most of these were females, but a few males were also observed.  After noticing that one dragonfly returning with a rather large and colorful prey item, I began trying for photos of them feeding.  Here are series of images of 2 different individuals, a male and a female.  They may have been feeding on the same kind of prey - some sort of red and black beetle.  The dragonflies would typically fly up rapidly and take their prey somewhere between one and two meters above the perch from which they took off.  They usually settled down near the take off point, and were pretty much unconcerned as I approached to within as close as a couple of feet to take these pictures.

Left and Right: Here is a male Erpetogomphus compositus feeding.  In the photo at left the tip of the prey's red abdomen can be seen while in the photo at the right a wing is also visible.

Left and Right: The female shown eating a red insect - not enough of the prey visible to identify except that it is the same shade of red as the other prey insects.  This unusual view shows the mouth in action from the ventral direction.  This individual worked from this barbed-wire fence for nearly 10 minutes, taking 3 prey and missing once in that time.

Below:  This series of photos shows the female Erpetogomphus with a second prey item.  In this sequence the prey is definitely seen to be a beetle. In the top left and right images the wing cases and legs are visible.  In the middle row, the abdomen tip (red) of the prey is visible.  In the photos middle right (below) and left, a wing is visible.

I attempted to catch this female after she caught another prey to have a voucher of the prey insect, but missed and she flew off out of sight.  My photo session was interrupted by a big storm system that came in rather suddenly, accompanied by lots of lightning and torrential rain.