Epargyreus

Hübner, 1819

Silverdrops, Flasher butterflies

Species Guides

Epargyreus clarus(Silver-spotted Skipper)
Epargyreus huachuca
Epargyreus zestos(zestos skipper)

Epargyreus is a of in the Hesperiidae, commonly known as silverdrops or flasher butterflies. The genus name derives from Greek argyros meaning 'silver,' referring to the characteristic white spot on the hindwing. occur across the Nearctic and , with the best-known species being Epargyreus clarus (silver-spotted skipper), which ranges from southern Canada through the United States to South America. Larvae construct distinctive leaf shelters using silk and are known for '-shooting' —expelling excrement up to 40 times their body length away from their shelters.

Epargyreus clarus by (c) christine123, some rights reserved (CC BY), uploaded by christine123. Used under a CC-BY license.

Silver-spotted skipper - Epargyreus clarus huachuca - Flickr - gailhampshire (1) by gailhampshire from Cradley, Malvern, U.K. Used under a CC BY 2.0 license.

MZLU-00129566 dorsal (51092576691) by NSG group from Lund, Sweden. Used under a CC0 license.

Pronunciation

How to pronounce Epargyreus: /ɛˌpɑrˈdʒɪriəs/

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Identification

The is distinguished by the presence of a large white or silvery spot on the surface of each hindwing, from which the 'silverdrops' derives. Members are relatively large skippers with robust bodies. -level identification requires examination of wing patterns, genitalia, and geographic distribution. Epargyreus clarus is particularly recognizable by its dark brown wings with golden-yellow bands and the prominent silver-white patch on the hindwing underside.

Images

Distribution

The occurs in the Nearctic and . Individual have distinct ranges: Epargyreus clarus extends from southern Canada through the United States to Mexico and South America; E. zestos occurs in Florida and the Antilles; E. exadeus ranges from Guatemala through Central America to Brazil and Argentina; and other species are restricted to specific regions such as Jamaica (E. antaeus), Mexico (E. aspina, E. brodkorbi, E. orizaba), and Argentina (E. tmolis).

Host Associations

Fabaceae - larval Larvae feed on various legumes; Epargyreus clarus has been documented on soybean (Glycine max), black locust (Robinia pseudoacacia), kudzu (Pueraria montana), and other Fabaceae
Soybean (Glycine max) - larval Epargyreus clarus larvae occasionally found on soybean but rarely reach economically damaging levels
Black locust (Robinia pseudoacacia) - larval Documented for Epargyreus clarus
Kudzu (Pueraria montana) - larval Accepted plant; larvae show no preference between kudzu, black locust, or red oak for shelter construction

Life Cycle

The exhibits multivoltine with both non-diapausing summer and diapausing winter generations. Larvae construct elaborate leaf shelters by cutting leaves and lashing them together with silk, forming structures described as 'tepees,' 'bungalows,' or 'condominiums.' occurs within these shelters. Summer generation pupal duration is 10–14 days, while winter generation pupae for several months. pupae survive at significantly higher rates than summer pupae despite longer exposure periods.

Behavior

Larvae are notable for '-shooting' —extruding their hind ends from shelters to propel excrement up to 40 times their body length away, potentially to avoid attracting . Larvae hide in silk-constructed leaf shelters during daylight hours and emerge at night to feed. exhibit rapid, darting typical of skippers.

Ecological Role

Larvae function as herbivores on leguminous plants, with occasional presence in agricultural soybean fields. The contributes to pollination as visit flowers. Larval leaf shelters and -shooting represent anti- adaptations.

Human Relevance

Epargyreus clarus is among the most widespread and recognizable North American skippers, valued by watchers. Larvae occasionally occur in soybean fields but rarely cause economic damage. The has been studied for its pupal survival , revealing counterintuitively higher mortality during short summer than long winter .

Similar Taxa

Other Hesperiidae generaMay share general skipper but lack the characteristic large silver-white spot on the hindwing that defines Epargyreus
UrbanusAnother Eudaminae with similar robust body form but different wing pattern; lacks prominent hindwing silver spot

More Details

Etymology

The name Epargyreus combines Greek elements, with argyros meaning 'silver' referring to the white spot on the hindwing

Species diversity

The contains approximately 20 recognized , with Epargyreus clarus being the most widespread and well-studied

Pupal survival paradox

Research by Brackley and Weiss (2023) demonstrated that pupae of Epargyreus clarus survive at higher rates (65% maximum mortality) than summer pupae (75% mortality in just 10 days), despite months-long exposure versus days-long exposure. Daily per capita mortality rates were an order of magnitude higher in summer, attributed to increased vertebrate activity.