Summertime Blues
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This time of year, our attention is pulled upwards toward the sky. The crystal blue skies of spring are a gorgeous backdrop for the bright greens of the new leaves on the trees. Birds flit around above us and sing from treetops, causing us to walk with our eyes scanning high. Trees like Tulip Poplar have bright and beautiful flowers blooming, as Crossvine and Trumpet Creeper add their blossoms to the upper levels of the forest. With all this activity above our heads, it can be easy to miss things at our feet. But this spring morning we are grateful we were scanning the ground as we made our way out of the tree line.
As we stepped into an opening, we happened to notice a small butterfly shape sitting atop a dew-covered blade of grass. The sun was shining in our face, and we could only see the backlit silhouette of what was obviously a diminutive butterfly. Careful not to frighten it, we slowly approached for a better look. Taking careful, soft steps, we circled around to put the sun at our backs and get a little closer. As soon as we saw the first hints of color, we knew which species we were looking at and it brought a smile to our face.
As with birds, flowers, trees, and even snakes, we look for a couple of quick and easy to spot field markers to help us identify butterflies. Some are simple, such as Eastern Tiger Swallowtail. Some are a little more difficult, such as the black swallowtails with purple and blue. It may take a few seconds of looking to know for sure, as opposed to knowing instantaneously. We’d like to share how we identified this butterfly, to help you when you’re in the field and encounter it. And we’d also like to share a little about where this lovely little butterfly fits into the overall Harmony Hill story.
One of the smaller butterflies at Harmony Hill, the Eastern Tailed-Blue (Cupido comyntas) looks a lot like their common name implies. When we say, “small”, we mean small; coming in at right around one inch in wingspan! They are blue above and have tiny tails that extend from both hindwings. That tail is one of the immediate identifying features of this species and one that we encourage you to focus on. There are a couple of other butterflies that look similar to the Eastern Tailed-Blue and, if you’re not careful, it wouldn’t be difficult to mistaken or misidentify them.
True to their names, male Eastern Tailed-Blues are blue when viewed overhead. However, females are predominately brown and can be fairly nondescript in appearance. Often informally lumped into “blues” with a few other species of small blue butterflies that look somewhat alike, this species is the only one in our area with tails. Formally, they are lumped into the Lycaenidae family and the Polyommatinae subfamily. But isn’t it easier for us to just call them “blues”? Though they may look like Spring Azures, Summer Azures, and Silvery Blues, the tails are one of two easy ways to separate Eastern Tailed-Blues from the other “blues”.
Two orange spots on the hindwings, often appearing as orange chevrons on the underside of the hindwings, are the other field marker to look for. As with the tails, none of the other “blues” possess such a physical trait. Their size, shape, behavior, and even overall color might give us pause, but focusing on the presence or absence of miniature tails and orange chevrons allows us to determine the identity of this species.
Also, be sure to look at the posture butterflies take when at rest. Some will sit with wings wide open, while others will rest with their wings clasped shut over their bodies. Eastern Tailed-Blues very often sit with their wings partially open, making identification much simpler. On this morning, the butterfly we observed rested with its wings closed; perhaps due to it being early in the day and the sun still very low on the horizon.
To warm themselves, some butterflies will open their wings in the rays of the sun. Gathering as much solar warmth and energy as they can, the increase in surface area is an efficient way to also increase their body temperatures.
How high or low they fly may also be a good clue to assist in identification. When it comes to Eastern Tailed-Blues, they are low fliers. Seldom getting above five to six feet, this species overwhelmingly prefers to cruise just a couple feet above the ground and the vegetation.
As we’ve discussed in our previous conversations about butterflies and moths, in order to have adult butterflies, you most often need to have larvae nearby. And as we know from talking about caterpillars, you need to have host plants for the adults to lay eggs on and hatch the larvae to munch upon. So, what host plants do we have at Harmony Hill that attract the presence of Eastern Tailed-Blues?
The top two host plants for this species are clovers; White Clover (Trifolium repens) and Red Clover (Trifolium pratense). Like so much of the southeast, or the entire United States for that matter, Harmony Hill has more than its fair share of nonnative White Clover. There aren’t many open areas that don’t have at least a few clover plants growing, meaning it is almost a forgone conclusion that we should have Eastern Tailed-Blues flying onsite. Upon seeing the male Eastern Tailed-Blue we observed for this week’s visit, we didn’t have to look too far to find deep green clover leaves spreading thickly in an opening. We took a few minutes to inspect the plants for eggs, but did not find any. During our walks, we will be certain to pay close attention, particularly if we see any females flying around.
Besides the two clovers species, other host plants for Eastern Tailed-Blues are also in the Fabaceae, or Legume, family. Members of the Lespedeza genus are host plants, and we have a couple species found over much of the property. Some of the vetch and pea plants, like Cow Vetch (Vicia cracca) and Eastern Milkpea (Galactia volubilis), are also known to host Cupido comyntas larvae. Though we haven’t documented female Eastern Tailed-Blues ovipositing on any specific plants, eggs on plants, or even yet observed caterpillars feeding on foliage, the abundance of clover and lespedeza here leads us to believe it to be the main host plant.
For the most part, the “blues” tend to have somewhat short flights. But Eastern Tailed-Blues are a bit of an exception, with a flight that lasts from March to October here at Harmony Hill. Compare that to their relative, the Spring Azure (Celastrina ladon), whose flight lasts from March to May. However, most adult “blues”, such as Summer Azure (Celastrina neglaecta), have a life measured in days. There is a lot to accomplish in that short life, such as reproducing and laying eggs. But they seem to do a fine job of doing just that, as we see a good number of each species each spring and summer in the meadows and fields of Harmony Hill.
The next gorgeous spring or summer morning you’re out for a walk in nature and you see a little one inch butterfly flying low to the ground, take a look to see if it is blue on top and gray on the underside. Chances are, it will be and, if it is, go straight into searching the hindwing for tiny tails and orange chevrons. You may very well be in the presence of an Eastern Tailed-Blue and a reminder to always look down, even as Mother Nature beckons your attention upwards to birds and leaves. Slowing down and looking all around you will reveal things often overlooked, and it will bring you more peace and joy with all you see.