https://phys.org/news/2019-01-big-genome-tiny-forest-defoliator.html

"The European gypsy moth has spread as far west as Minnesota and as far south as North Carolina. The rather slow spread—about 13 miles a year—is partly due to the fact that EGM females are flightless and must walk or be blown by the wind to disperse," said Dr. Gammon, Assistant Professor of Microbiology and a W.W. Caruth, Jr. Scholar in Biomedical Research. "In contrast, females of the Asian gypsy moth subspecies, which inhabits Asia and eastern Russia, have larger, more developed wings and can fly."

If the Asian gypsy moth were to become established in the United States, it would pose an even greater economic threat due to its ability to spread more swiftly, he added. To guard against that possibility, the U.S. Department of Agriculture has surveillance programs at several ports and regularly sprays virus-based bioinsecticides in endangered forests to kill gypsy moth caterpillars.