This butterfly is so abundant across the United States that some suggest that besides the monarch it should be named the national butterfly.
Gray hairstreaks are not currently endangered or threatened.
US Federal List: no special status
CITES: no special status
State of Michigan List: no special status
After about six days the eggs hatch, and over the next twenty days the caterpillars grow and develop. They then form a chrysalis and after about ten days emerge as adults. Silvery-blues spend the winter as pupae and can have three or more generations per year. Development time can vary greatly depending on geography and the different hosts.
Development - Life Cycle: metamorphosis ; diapause
The larvae of gray hairstreaks, when abundant, can become pests to commercial crops, including cotton, beans, corn, and hops. Habits such as these have earned the caterpillar the common name of "cotton square borer" and "bean lycaenid".
Negative Impacts: crop pest
Gray hairstreaks benefit humans just as so many other butterflies, bees, and small birds do. The butterfly participates in a mutualistic relationship with many flowering plants by receiving nutrients (nectar) and acting as a pollinator.
These generalists feed on (and likely pollinate) a wide variety of plants. They also may be eaten by a wide variety of predators.
Ecosystem Impact: pollinates
Just as in many other characteristics of gray hairstreaks, their food habits are general. Neither the caterpillar nor the butterfly are specific to any certain plant or flower, but rather feed on a variety of plants. The larvae eat from at least twenty different families of plants, including the pea and mallow families. Normally they can be found eating fruits and flowers. They can also be found on maize, cotton and a variety of shrubs and trees. The butterfly feeds on nectar from a wide variety of flowers.
Plant Foods: leaves; fruit; nectar; flowers
Primary Diet: herbivore (Folivore , Frugivore , Nectarivore )
Gray hairstreaks can be found in Southern Canada to Central America and Northwestern South America. They occur from coast to coast and in a variety of altitudes ranging from sea level to nine thousand feet.
Biogeographic Regions: nearctic (Native ); neotropical (Native )
Unlike most butterflies, gray hairstreaks do not prefer one specific habitat. They are widespread in tropical forests and open, temperate woodland areas. They can also be found in meadows, crop fields, neglected roadsides, and residential parks and yards are often homes of this fascinating butterfly.
Range elevation: 0 to 2745 m.
Habitat Regions: temperate ; tropical ; terrestrial
Terrestrial Biomes: forest ; rainforest ; mountains
Other Habitat Features: suburban ; agricultural
In the earlier stages of the life cycle, gray hairstreaks are straw, purplish-white, pink, reddish-brown, or green larvae with various other paler marks. The head is yellowish-brown. Throuhout Texas, however, the larvae have been noted to be entirely green and covered with short hairs. The pupae hibernate and are usually brownish in color. In the adult stages of the life cycle the butterfly's upper wings are dark grayish brown with a prominent orange spot located at the outer margin close to the shorter of the two blackish tails. The conspicuous orange spot is larger than most Strymon species. The hind wing is gray (darker in males and spring adults than in females and summer adults). It too has a black-eyed orange spot at the bases of the hindwing tails. There is a small patch of blue before the tail, and two broken crossbands of black and white spots. The male abdomen is orange. The wingspan varies from 2.6 to 3.65 cm.
Range wingspan: 2.6 to 3.65 cm.
Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry
Sexual Dimorphism: sexes colored or patterned differently
Mating and egg-laying occur in early spring. Adult males perch on small trees and shrubs from early afternoon to dusk to await females. They usually perch at a level where they can catch cooler breezes, lower to the ground in the spring and higher as the year goes on. Males back dorsally. Mating pairs are normally spotted at night, and females oviposit during the midafternoon. The females then lay their pale green eggs on hosts' buds or newly opened flowers of the host plant.
Breeding season: early spring
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (Internal ); oviparous
There is no parental involvement once eggs are laid.
Parental Investment: pre-fertilization (Provisioning)
The gray hairstreak (Strymon melinus) is also called the bean lycaenid or cotton square borer. It is a member of the Lycaenidae family, known as the gossamer-winged butterflies and the second-largest family of butterflies. It is one of the most common hairstreaks in North America, ranging over nearly the entire continent. It also occurs throughout Central America and in northern South America.
The adult gray hairstreak has a wingspan of 20–32 millimetres (0.79–1.26 in). The upper sides of the wings are gray with an orange spot on the hind margin. The underside of the wings are a lighter gray with white and black lines and orange and blue marginal spots near the hind-wings' tail-like extensions.[3]
Caterpillars are green with markings on the sides, covered in short yellow hairs.[3] Like other caterpillars in the Lycaenidae family, S. melinus are attended by ants in a behavior known as myrmecophily.[4]
The gray hairstreak lives in a wide range of habitats ranging from tropical forests and mountains to temperate woodland areas and meadows, as well as cities and farmland.[3][5]
The caterpillars of the gray hairstreak butterfly consume a wide range of food plants.[3] However, they do mainly use mallows and legumes as their preferred host plant. They commonly use clovers as their food plant as well, eating rabbit-foot clover (Trifolium arvense), white clover (T. repens), bush clover (Lespedeza capitata), white sweet-clover (Melilotis alba), and Malva neglecta. Young caterpillars are typically found eating flowers and fruiting bodies of their host plant while the older caterpillars eat the leaves.[6]
The gray hairstreak (Strymon melinus) is also called the bean lycaenid or cotton square borer. It is a member of the Lycaenidae family, known as the gossamer-winged butterflies and the second-largest family of butterflies. It is one of the most common hairstreaks in North America, ranging over nearly the entire continent. It also occurs throughout Central America and in northern South America.
