Strymon melinus
In 3 days ~30% in a week ~60%
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. These extensions twitch while at rest, and may imitate a separate head to encourage predators to go for the wings, potentially allowing the insect to survive.
Caterpillars are green with markings on the sides, covered in short yellow hairs. Like other caterpillars in the Lycaenidae family, S. melinus are attended by ants in a behavior known as myrmecophily. The gray hairstreak lives in a wide range of habitats ranging from tropical forests and mountains... Wikipedia →
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Austin | 🇺🇸 United States | |
| 2 | Dallas | 🇺🇸 United States | |
| 3 | Valencia | 🇻🇪 Venezuela | |
| 4 | San Antonio | 🇺🇸 United States | |
| 5 | Sacramento | 🇺🇸 United States | |
| 6 | Portland | 🇺🇸 United States | |
| 7 | Tijuana | 🇲🇽 México | |
| 8 | Mesa | 🇺🇸 United States | |
| 9 | San Francisco | 🇺🇸 United States | |
| 10 | San Diego | 🇺🇸 United States |
With luck
About 10% of wildlife watchers report a Gray Hairstreak sighting in San Diego on a given day, based on 706 verified sightings from GBIF citizen-science data. It is the 17th most-seen of the 693 insects we can rate there. Over three days the chance rises to about 30%, and over a week to about 60%, if each day is a fresh chance.
July to October
In those months about 20% of wildlife watchers report a Gray Hairstreak in San Diego on a given day, against under 5% in December and January, the lowest months. Those are among San Diego's driest months, with about 5 mm of rain a month against 55 mm in February.
Between 11 am and 2 pm
Across all the parks we cover, that three-hour window holds the most Gray Hairstreak sightings with a recorded time, and nearly all of them come between 6 am and 6 pm: it is a daytime animal.
10th of 32
Of the 32 cities where we can rate Gray Hairstreak sightings, San Diego ranks 10th at about 10%. The best odds are in Austin (United States, about 30%), Dallas (United States, about 30%) and Valencia (Venezuela, about 20%).
Same family: Lycaenidae
The closest relatives of the Gray Hairstreak that you can see in San Diego (family Lycaenidae, Gossamer-winged Butterflies) are Marine Blue (about 10%) and Western Pygmy-Blue (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Gray Hairstreak is recorded against all the insects logged in San Diego (706 verified sightings), calibrated against known sighting rates. Figures are rounded to the nearest 10% because citizen-science data supports honest approximations, not decimals, and months with records from fewer than five people show "—". How it works.
