Initially the seperation of Large and Small Red-eyed Damselflies can appear tricky. However, with careful observation they can be postively identified. Identification usually requires oberservation through binoculars or a telescope because both species tend to sit out on floating weed some distance from the bank. Digiscoping can get you pictures that can confirm identification.

The features to look for are given below.

Large Red-eyed Damselfly Note that the blue making on the tail of the male is confined to segments 9 and 10 and appears sharply cut off. Segment 8 of the abdomen appears all dark brown. The sides of the thorax of the female and the lower part of the abdomen close to the thorax is distinctly green. Large Red-eye tend to prefer to sit on the large floating leaves like Water Lily and, as in the photo larger pond weeds.

Small Red-eyed Damselfly Note that the blue making on the tail of the male is relatively large and distictly wedge shaped. The bottom of segment 8 is blue and the top appears dark brown. Also, note the up curved abdomen of the single male. This is a very good indication that the individual is a Small Red-eye. Check other characters though because I am not sure this is 100% reliable. The sides of the thorax of the female and the lower part of the abdomen close to the thorax is distinctly blue. Small Red-eyes tend to prefer to sit on semi-submerged plants like Hornwort and Water Millfoil. However, you will see both species on a variety of water plants.

Photos by Kay Reeve FRPS

Banner artwork by Joan Sharrett