There are few butterflies less picky about where it lives and what it lives on than this guy, the gray hairstreak, Strymon melinus. Or put another way, there are few as adaptable as the gray hairstreak.
You'll find gray hairstreaks in the broad, open plains of the Midwest, even as far north as southern Canada. You'll find them along the Atlantic coastal plain and in the mountains of the Pacific Coast. And you'll find them in subtropical South Florida and just about every other part of the Sunshine State. And unlike some butterfies, it definitely is not picky about what it uses as host plants for its offspring or what it nectars on as adults.
The name pretty much tells you what the gray hairstreak looks like. It is a relatively small, with a wingspan that measures between an inch to about an inch and three-eighths across, blue-gray in color, two jagged lines that run through fore- and hindwings — the hairstreaks— and a large red spot near the tail. Males and females look alike, but gray hairstreaks do vary by season, darker gray in the spring and the fall, lighter gray in summer.
It is the most widespread hairstreak butterfly in North America, found in southern Canada, pretty much across the United States, with the exception of the Rocky Mountain states, south through Mexico, Central America and into the shoulders of South America. Its range includes all of Florida's 67 counties. Up north, the gray hairstreak produces two generations during the time that they're active; down south, they'll produce three or four. In Florida, they're active, or in flight, between March and November. Up north, it's limited to May through September. Preferred habitats include tropical forests and temperate woods and just about everything in between — meadows, scrubs, farm fields, parks, roadsides and other disturbed areas. They're comfortable at sea level and in mountains up to 9,000 feet.
As we said, gray hairstreaks are not particularly picky when it comes to host plants. Males perch in small trees and shrubs waiting for a receptive female to come by. Fertilized females then lay their eggs singly on the buds or flowers of members of the pea, mallow (hibiscus), clover and cotton families among others. The eggs are green and somewhat flattened. The larvae are about a half-inch long, green to pinkish green, sometimes light brown, with brown heads when they mature; they go through four instars, or development stages, over a period of 20 days before pupating. They'll remain in their cocoons for 10 more days before emerging as adults. That time schedule can vary by geography and by host plant. Nectar plants for adults are equally varied and include dog bane, milkweeds, mints, beggar's tick, goldenrod and clover. Because of their wide-ranging tastes, they're important as pollinators.
On the other hand, the caterpillars, called by some the cotton square borer and by other others the bean lycaenid, can damage commercial crops if they're present in large enough numbers. It's rare, however, that the damage they inflict warrants the use of insecticides. The caterpillars are often called cotton square borers and bean lycaenids because of their affinity for those plants.
Gray hairstreaks are members of hairstreak subfamily, Theclinae, and a member of Lycaenidae, the family of gossamer-winged butterflies.