Gray Hairstreak (Strymon melinus)
The Gray Hairstreak is a species of butterflies common in almost entire North America and is very common throughout their range. The tiny butterflies belong to the hairstreak group and are often tended by ants in their host plants from which they can very easily be identified.
Scientific Classification
- Family: Lycaenidae
- Genus: Strymon
- Scientific Name: Strymon melinus
Description and Identification
Caterpillar
The caterpillars are green, with a line running down from the head to the end. Young caterpillars live on flowers and fruits, while the older ones (at the final stage) may consume leaves. The flowers and fruits are chosen from innumerable varieties of plants especially from pea (Fabaceae) and mallow (Malvaceae) families that include beans (Phaseolus), clover (Trifolium), and cotton (Gossypium).
Pupa
The pupa has a shelled-groundnut-like shape and color, with fine velvety protrusions all over the body. It takes around 7-10 days to emerge into a butterfly. However, it would enter hibernation if the stage coincides with the winter.
Adult Butterfly
Sexual Dimorphism: Vaguely present
Color and Appearance: When the wings are open, the dorsal side displays a bright blue-gray coloration with a large red spot near the ends. When the wings are closed, the color of the ventral side during spring and fall is dark gray, while during summer, the color turns paler. The white postmedian line is relatively straight with an orange border on the inside edge. Each of the hind wings has a small tail-like protrusion that, by adaptation, looks almost like the antenna, while they render a head-like appearance on the wingtip in order to confuse predators. When the wings are closed, the ventral side shows a similar appearance as the dorsal. The female butterflies are relatively pale and shorter than the males.
Average wingspan: 7/8 – 1 3/8 inches (2.2 – 3.5 cm)
Flight pattern: Fast and erratic
Quick Facts |
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Distribution | Almost in the entire North American continent, Central America, down to the northern regions of South America |
Habitat | Commonly found in disturbed, weedy areas, open lands devoid of dense vegetation |
Lifespan of adults | 3-4 weeks in an average |
Host plants | In Central America: Passionflower species Passiflora oerstedii and Passiflora menispermifolia
Elsewhere: Various passion flower species |
Adult diet | Nectar several flower species, mainly mint, winter cress, sweet white clover, dogbane, milkweed, goldenrod, and tick trefoil |
Did You Know?
- In some regions within their habitat, the caterpillars are considered as pests, since they often cause economic damage to crops like cotton, bean, etc.

