First-spotted Four-spotted

Emptying out the moth trap in the morning, I found one moth I hadn’t noted the night before, a Peppered Moth (Biston betularia), a holarctic species made famous in England after studies of its industrial melanism. In addition to this one large moth and several large June Beetles, there were numerous tiny insects, mostly flies and beetles. Just as there are micro-moths, it appears there are also micro-beetles, beetles that don't get larger than several millimeters in length.

In the afternoon, I walked to St Olaf. Noticed some flies along the way. And, at the small hub meadow, in addition to Eastern Forktails and a female Dot-tailed Whiteface, I spotted the first Four-spotted Skimmer of the year. A large, golden dragonfly with a black spot at the node of each of its four wings. Like the Salt & Pepper Moth, the Four-spotted Skimmer is a holarctic species; it can be found around the entire northern hemisphere: in Japan, in Siberia, in Europe...there’s even a relict population, held over from the last glaciation, in the mountains of Morocco.

In Europe, this dragonfly is known to migrate. There have been several occasions in Northfield where an irruption is the only likely explanation for the sudden appearance of vast numbers of Four-spotted Skimmers. One year, in particular, stands out. I found dozens everywhere I walked, even our own backyard had a number. I have a photograph of two perched and holding on to our car’s antenna in our driveway. Another curious observation, more recent, is seeing this dragonfly perching and taking feeding flights high in our neighbor’s white pines, at least forty feet off the ground.

Posted on May 16, 2017 03:34 AM by scottking