Washington Area Butterfly Club


Field Reports



August 1999

August 17 and 18 -- Harry Pavulaan

Sterling, VA. Red-banded Hairstreaks are having a noticeable population irruption in the Washington D.C. suburbs this year. I first observed the summer brood in my Herndon garden on July 17, and numbers slowly increased until the end of the month. At that time, they were attracted mainly to my Indian Hemp, Bronze Fennel and Orange Butterflyweed. Interestingly, they avoided the other Fennels. By early August, they started swarming on my Joe Pye flowers, flying until sunset and even later on the hotter days. One evening, I went out after dark with a lantern and found two individuals sleeping on the upper- and undersurfaces of Joe Pye leaves, fully exposed. On August 18, I counted a whopping 36 in my garden. Most of them were swarming on my Joe Pye, though some were still found on the Bronze Fennel and Orange Butterflyweed (second bloom after dead-heading the flowers). I discovered their love for Peppermint, with 6 of them either nectaring on the few blooms or resting on the leaves.

During a visit to a friend's house in Vienna on August 17, I observed about a dozen Red-banded Hairstreaks in the shaded understory beneath some very tall shade trees. About a half-dozen were flying about a Quince tree that is fruiting. I noted the absence of Sumac in the area, and then realized that Sumac is not a major component in the area around my home, nor in nearby Runneymede Park. Last year, I observed a female laying an egg on an unopened flower bud of one of my Butterfly Bushes, while in 1997, I observed a female laying an egg on garden mulch beneath another Butterfly Bush. It makes me wonder if the species simply uses any leaf litter or detritus as the larval host. Perhaps the assumed primary host relationship with Sumac is based mainly on the species' affinity for the fragrant Sumac blossoms.

When raising Red-banded Hairstreaks, the females will freely lay eggs around the top of plastic terrariums (the kind with the colorful plastic covers). I learned from Tom Allen (West Virginia) that the caterpillars will eat Lettuce. This species is easy to raise, since the caterpillars easily handle neglect, as long as there is a sufficient supply of dried leaves (I still use Sumac) or lettuce to last about a month! However, the leaf litter should be misted or sprinkled lightly with water every few days to provide the caterpillars with some needed moisture. They seem to handle mold well, and have been observed eating moldy leaves.
Page created 19 August 1999