Juba Skipper

Hesperiidae, or skipper butterflies, typically have large, stout bodies that are disproportionately larger than their wings. These types of butterflies also have hooked antenna tips, as opposed to the clubbed tips that are more common in other butterfly types. Hesperia juba butterflies have similarly large, moth-like bodies with hooked antennae and greenish-brown hindwings. Juba skippers are distinct from other skipper butterflies due to their larger thoraxes with intense blue-green hairs and the presence of distinct white spotting on their underwings. Male Juba skippers typically have bright orange-brown upperwings with toothed borders, while females have larger upperwings with more striking orange and yellow markings. The larvae of H. juba vary by instar. At the first instar, hatchlings are a cream white color with black head capsules. They later develop into a greenish color after feeding on grass. At the second instar, the caterpillars maintain the creamy white color, but with some small dark spots dotted around their bodies. At later, more mature instars, the caterpillars have plain green-brown colors, but maintain their dark head capsules.

The juba skipper's range spans North America, with northern limits in British Columbia, Canada and southern limits in northern Arizona and northwestern New Mexico. It is most common in the United States, with distributions in Arizona, southern California, Colorado, Idaho, Montana, North Dakota, New Mexico, Nevada, Oregon, South Dakota, Utah, Washington, and Wyoming. H. juba is a strong flying montane butterfly and has been observed in a wide range of elevations. It has been observed at up to 3292 m elevations in Rocky mountain states and at least 2743 m in north California. It has also been reported in ranges from 21 m to 2896 m in Oregon. It is also most commonly seen in the Cascades, but rarely in the north Coast Range, which suggests that butterflies in this area are temporary colonists.

H. juba are highly territorial and solitary insects. Therefore, their social behaviors are limited to locating and securing mates. Male butterflies typically wait for females by perching on the ground or in gullies. With this, males become highly active and aggressive when other insects or butterflies encroach upon their perching spots. Females also exhibit solitary behaviors. They typically lay their eggs singly on host plants.

H. juba larvae feed on different types of grasses. Specific types of grasses include those in the following families: Bromus, Deschampsia, Koeleria, Poa, and Stipa. Adult butterflies, however, feed on flower nectar and mud. Some flower species include those in the following families: Allium, Balsamorhiza, Barbarea, Centaurea, Chrysothamnus, Erigeron, Eriogonum, Erysimum, Habrouria, Heterotheca, Liatris, Medicago, Physocarpus, Senecio, Symphyotrichum, and Syringa.