Date of this Version
Insecta Mundi 0330: 1-5 (2014)
Cupido comyntas (Godart), the eastern tailed-blue, is a legume-feeding caterpillar native to North America. One of its three subspecies, Cupido comyntas comyntas (Godart), is distributed over the eastern half of the United States and southeastern Canada. This subspecies was recorded for the first time feeding on cultivated soybean. Caterpillars fed upon soybean at various developmental stages, ranging from seedlings to podded plants, in several fields within a 5-km radius in Brookings County, South Dakota, from July 1 – 25, 2013. Feeding was confined to leaves, and no pod damage was observed. The caterpillars occurred at relatively low densities that were unlikely to have affected yield of soybean crops. An early maturity soybean line, H007Y12, had a lower incidence of C. comyntas comyntas caterpillars than a relatively later maturity line, H19Y11. Butterflies of C. comyntas comyntas were observed feeding from soybean flowers on multiple dates in July and early August. As the geographic distribution of C. comyntas comyntas considerably overlaps the area where soybean is grown, entomologists should watch for and document any additional infestation of soybean by these caterpillars.