Art Shapiro's Butterfly Site - Hesperiidae

Amblyscirtes vialis

admin — Sun, 28 May 2006 18:09:50 +0000

Local and generally uncommon; along roadsides and streamsides in dappled light and shade in moist habitats within forest; very local. Found in the Coast Range/Bay Area and on the Sierran West slope, foothills to (rarely) 7000'. It often co-occurs with the Arctic Skipper, Dreamy Duskywing, Western Tailed Blue, Clodius Parnassian, Gray-Veined White, etc. Males perch on leaves in sunflecks and occasionally visit mud puddles. There is no color or pattern variation, and the sexes are nearly identical.

This is our only member of a large genus whose metropolis is in the desert Southwest and adjacent Mexico. Our species is the most widespread in the genus, occurring all the way from our area to the Atlantic coast states.

There is one brood, flying April to July (later at higher elevations). The host plants are known to be native grasses but no precise identifications have been made in our area.

Adults visit small woodland flowers - vetches, mints, dogbane, etc. They are so inconspicuous that they are often overlooked. One well-known Bay Area collector had never noticed this species despite several decades of field experience!

Atalopedes campestris

admin — Sun, 28 May 2006 18:09:44 +0000

Somewhat weedy, this robust skipper is often found breeding in mowed lawns and visiting garden flowers - famously, in Capitol Park in downtown Sacramento! Widespread near sea level and in the lower foothills; less common in the coastal fog belt than inland. In recent years this species has seemingly reacted to global warming by expanding its range from northern california to central Washington State and Idaho. More recently still, it has jumped the Sierra and invaded the western great Basin, becoming established in Sierra Valley, Carson Valley and near Verdi, NV. It also has been very responsive to spring temperatures, emerging nearly a month earlier than it did near Sacramento 30 years ago. It is primarily an open-country species (grassland, agricultural land), but occasionally turns up along roadsides in mixed mesic mid-elevation forest. It tends not to persist in such situations.

Several broods per year (March-November in Sacramento Valley), the autumn brood always by far the most abundant. June-October at Sierra Valley. There is plenty of individual color and pattern variation. Autumn females are usually very dark, chocolate-brown beneath with distinct yellow spotting. Males are perchers , generally well off the ground.

Larval hosts grasses, including Bermuda Grass (Cynodon dactylon), Dallis Grass (Paspalum),and various others. An eager flower visitor, often seen at Tall Blue Verbena, Goldenrod, Rabbitbrush, Coyotebrush, Alfalfa, Thistles, Dogbane, etc.

Carterocephalus palaemon

admin — Sun, 28 May 2006 18:09:37 +0000

The Arctic Skipper is not truly arctic, but is circumboreal, occurring in cool, wooded, usually streamside habitats across northern Eurasia and North America. Our transect is right at its southern range limit in California. There appears to be a small population near Washington, Nevada County which was discovered only a few years ago (though it was probably there all along; it occurs at low density and is not seen every year). There may be others on the West slope in similarly cool, wet, shaded places. Adults sit in sunflecks and visit flowers, particularly native vetches which they pitch up onto from below. The larval hosts are presumed to be native grasses. There is one brood in early summer (May-July).

Epargyreus clarus

admin — Sun, 28 May 2006 18:09:23 +0000

Locally common in the Western Sierra foothills and in the Coast Range north of the Bay. Formerly present (very locally) in the Sacramento Valley, but there are no current records. Found in riparian habitats, often in canyon bottoms, but something of a fixture in Gold Country towns where it breeds on introduced Black Locust (see below). There is nothing else in our fauna that can be confused with it.

A very strong flier, the silver patch flashing in the sun as it moves through dappled light and shade. An avid visitor to Milkweed, Dogbane, Yerba Santa, native perennial Vetches, California Buckeye and garden flowers such as Lilac and Buddleia.

Our subspecies (E. clarus californica), unlike the widespread nominate one in eastern North America (E. c. clarus), has only one brood, in late spring (April-July), but scattered late records suggest at least the potential for multivoltinism. The larva, which lives in a nest of several leaflets tied together with silk, is very comical-looking with a large purplish-brown head bearing two round orange "eyespots." It accentuates the clownishness by hurling fecal pellets if disturbed. The native host plants in our area are the large, coarse perennial Lotus crassifolius and the uncommon riparian shrub Amorpha. It may also use perennial vetches of the genus Lathyrus. In the Gold Country, however, it routinely breeds on Black Locust (Robinia pseudacacia), which was often planted in Gold Rush days and has escaped in some places (mainly along roadsides). This is the usual host of the Eastern U.S. subspecies and it would seem it was preadapted to it. Right now a Neotropical ornamental, Argentine Flame Pea (Sesbania punicea) has escaped from cultivation and is becoming a serious riparian weed in the Sacramento Valley. When this butterfly meets it, it may be another case of "love at first bite."

Erynnis brizo lacustra

admin — Sun, 28 May 2006 18:09:22 +0000

A narrow endemic in our fauna, restricted to serpentine soils in both the Coast Range and Sierra Nevada foothills, where its only known host plant in the North State, Leather Oak (Serpentine Scrub Oak), Quercus durata, occurs. Its southernmost population in our area is at Meadowbrook, near Georgetown. Farther south in both ranges it is not confined to serpentine and seems to use several shrubby oaks as hosts, but never in our area.

There are breeding populations near Nevada City, Grass Valley, and Coloma, but this species occurs on our transect only as a very rare stray.

An avid puddler. Commoner in the North Coast Range than in the Sierra, where it is usually seen twisting into and among leather oak thickets - magically going into one, but coming out of another! Visits wild onion, yellow Composites, etc. One brood only, March-June.

Erynnis funeralis

admin — Sun, 28 May 2006 18:09:21 +0000

This species ranges from the San Joaquin Valley to central Argentina and Chile. In most places its host plant is cultivated Alfalfa (Medicago sativa)! It is only an accidental or stray species in our area. It can be told from the Mournful Dusky-Wing, E. tristis - which is common and resident - by its rather long, narrow, pointed forewing, often with a coppery-reddish cast. The shape of the forewing makes the hindwing look very broad. Multiple broods.

Erynnis icelus

admin — Sun, 28 May 2006 18:09:20 +0000

Uncommon and rather poorly-known in California, this is a species of cool, moist forest - often seen along muddy streamsides, sitting with wings fully expanded. It ranges from the upper foothills to mid-elevation (roughly 1500 to 6000' at the latitude of I-80). The only other small Dusky-Wing with a "chain-dotted" forewing pattern is the larger, serpentine-endemic Sleepy Dusky-Wing, E. brizo lacustra. Note the squarish, "cut-off" forewing shape of E. icelus!

One brood in late spring (April-June). Host plant willow (Salix), but life-history not well studied in California. This species extends all the way to the Atlantic Coast and may be a relict in our fauna. In the Bay Area it is recorded (oddly) only from Sonoma County.

Erynnis pacuvius

admin — Sun, 28 May 2006 18:09:19 +0000

An uncommon species found in both the Coast Range and Sierra Nevada, mostly in chaparral and along roads in mesic forest where it often puddles. Confusingly similar to the Persius Duskywing but always single-brooded, and usually identifiable by habitat and plant association. It has a gloss or lustre usually missing in the "matte" persius and lacks a white dot at the end of the forewing cell above. In fact, it is very dark. Late spring-early summer; host plants various species of Ceanothus; the reasons for its scarcity are unknown.

Erynnis persius

admin — Sun, 28 May 2006 18:09:18 +0000

Locally common in a wide variety of habitats from sea level (including the Central Valley) to 7000',but rarely seen on the East slope. Many of its colonies are transient, especially at low elevation where its hosts are often annuals.It often disappears from an area for years on end, then reappears suddenly. It has, however, been a long-term permanent resident at Lang Crossing. This is the only small Dusky-Wing with multiple broods--three at 5000'. This in itself is a valuable aid to identification.

Males are good puddlers and often fly in circles around patches of the host plant. They are avid visitors to Pink Dogbane and Vetch flowers and often visit others. They usually occur in the open, along streamsides, in grassland or rocky balds, but also along roads through mesic mid-elevation forest. There are differences in details of the wing pattern between the spring and later broods. The well-developed light spot on the forewing upperside at the end of the discal cell is a good way to tell this species from E. pacuvius.

The hostplants are all Fabaceae, including both annual and perennial species of the genus Lotus. Spanish Lotus, L. purshianus, is a frequent choice at low elevation. The introduced perennial, Bird's-Foot Trefoil (L. corniculatus) does not seem to be used.

Erynnis propertius

admin — Sun, 28 May 2006 18:09:17 +0000

Our commonest and most widespread Erynnis, easily recognized in our area by its large size, brown hindwing fringe, and two light spots near the outer angle of the hindwing beneath. It occurs from sea level to 9000', though the individuals seen above 7000' seem to be hilltopping fly-ups and there is no evidence of breeding up there (in fact, there are often no hosts). An avid puddler, often in large numbers, it occurs in woodlands and forests but is very nearly gone from the Central Valley.

In theory this is a single-brooded species (February to July, depending on site), but at Gates Canyon it has repeatedly produced a partial second brood in mid-to-late summer. Second-brood individuals are subtly different in phenotype from firsts. The same is true of the related Eastern species E. horatius, which also produces one or more summer broods.

Larvae live in rolled-leaf nests on a variety of tree Oaks, both deciduous and evergreen. I have not found them using exotic species in cities or parks-at least not yet.

Adults visit many flowers, including Vetches, Blue Dicks, Phacelia, Fioddleneck, Yerba Santa, California Buckeye, Dogbane, Milkweed, Pussy Paws? you name it. Males perch and hilltop, but are not obligate hilltoppers.

Erynnis tristis

admin — Sun, 28 May 2006 18:09:16 +0000

Common below 2000', including the Sacramento Valley; the only Erynnis routinely found in cities. A strong flier but not a very dedicated puddler, it is multiple-brooded, from March to October. This is the only common Dusky-Wing with a white fringe (compare E. funeralis).

Host plant oaks (Quercus), ovipositing on young, tender growth only and thus generally confined to Valley Oak (Q. lobata), which continues growing all summer, and cultivated Oaks receiving summer water, including Cork Oak (Q. suber), from the Mediterranean Region, which seems to be one of its favorites! Males hilltop in the foothills. Visits Tall Blue Verbena, Yuerba Santa, California Buckeye, etc. and a variety of garden flowers, especially Buddleia davidii.

Heliopetes ericetorum

admin — Sun, 28 May 2006 18:09:02 +0000

This species is uncommon in our area but can turn up literally anywhere, from sea level to near tree-line-generally as singletons. It appears to migrate through our area twice a year, northward in May-June and southward in September-October, but we do not know where it is coming from or where it is going. Breeding populations are scarce, generally in chaparral, where the host - Bush Mallow, genus Malacothamnus, occurs. Adults visit a great variety of flowers and turn up as often in urban and suburban gardens as anywhere else.

Hesperia colorado harpalus

admin — Sun, 28 May 2006 18:09:00 +0000

The taxonomy of this entity has undergone some very unfortunate turbulence recently. It used to be put in the species Hesperia comma, and its subspecifixc name used to be yosemite. The name harpalus was used for the East slope subspecies, which is very different. (Got that?) As now construed, harpalus refers to the single-brooded entity with a very lightly-marked, mostly golden ventral hindwing in the male and a highly variable spot-pattern on the same wing in the female, incorporating a c-shaped element on the basal half. It occurs on non-serpentine substrates, in dry meadows and along wood roads, visiting Pink Dogbane, Coyotemint, Eriogonum nudum, and other flowers. It flies in June and July, after H. lindseyi where they co-occur or come close, and as late as September at Donner. Hilltopping males are taken on Castle Peak. The West and East slope subspecies not only look very different; they have strong molecular-genetic differences and are only known to intergrade in the Feather River Canyon, north of our area. Larvae feed on perennial grasses. Oddly, the only host definitely identified at one of our sites is a naturalized exotic, Sweet Vernal Grass (Anthoxanthum odoratum).

Hesperia colorado idaho

admin — Sun, 28 May 2006 18:08:59 +0000

Until recently, this was known as Hesperia comma harpalus. Now the name harpalus has been switched to the very different West slope entity (formerly called yosemite) and most North American populations have been removed from species comma to colorado. At any rate, this insect is common along the Sierran East slope, including Sierra Valley, and on into Nevada. It looks very unlike the West slope animal. The body pelage is bluish and the hindwing underside is greenish with large silvered spots; the animal looks like a miniature Hesperia juba. Were it not for the complete intergradation that occurs in the Feather River Canyon, it would be hard to imagine that the two subspecies were in fact conspecific. Hilltopping individuals occasionally turn up on Castle Peak, along with the West slope subspecies!

One brood, June-August, in grassland and shrub-steppe, often in alfalfa fields. Larval host plant presumably perennial grasses. Adults often visit alfalfa and thistle flowers.

Hesperia colorado ssp.

admin — Sun, 28 May 2006 18:08:58 +0000

Populations of Hesperia colorado (as determined by the genitalia) occur at scattered locations on the Sierran west slope on serpentine substrates and fly in autumn - mid-September into October. One of these occurs on serpentine along Washington Road, where it is sandwiched between "normal" populations of what is now called H. colorado harpalus but used to be called H.comma yosemite, which fly in June-July both higher and lower but on metasedimentary substrates! The seasonal displacement of these populations means they cannot exchange genes with others and they are thus behaving as if they were a species in their own right. Both sexes are, on average, darker on the ventral hindwing than nearby early-summer ones. The only nectar source available to these insects is a dwarf serpentine-endemic ecotype of Rabbitbrush (Chrysothamnus nauseosus). There are late-flying, very dark populations on serpentine in far northern California (named as subspecies mattoonorum), but it is not clear that they are related in any way to these. Molecularly, the serpentine-autumn populations resemble the nearby summer ones, not the autumn-flying entity found in the High North Coast Range.

Hesperia columbia

admin — Sun, 28 May 2006 18:08:57 +0000

The Columbian Skipper is found mainly in the Coast Range. In the Sierra Nevada it is known from only a handful of localities, mainly on serpentine. None is on the transect. Its only population on the transect is in the chaparral at the head of Gates Canyon; individuals are encountered only sporadically on the sampling route, but if the route included any rocky summits it would be a "regular" since it is a confirmed hilltopper. It also occurs in Lagoon Valley Regional Park, where it hilltops along the crest of the Cement Hill range. There are two broods, in May-July and September-October. The hosts are unidentified native bunchgrasses.

Adults often visit Goldenrod, Yellow Star Thistle and Rabbitbrush in the fall.

The very unusual underside pattern makes this uncommon skipper easy to identify.

Hesperia juba

admin — Sun, 28 May 2006 18:08:56 +0000

A striking, large skipper, like a very big East-slope Colorado Skipper with a strongly greenish tinge to the body pelage and hindwing beneath; a very strong flier; males perch on or near the ground. Although strays are occasionally taken at low altitudes, this is quintessentially a montane species, from 2000' to tree-line. It flies shortly after snowmelt (early June at Donner, e.g., visiting early Dandelions and Pussy Paws) and again, much more commonly, in autumn (August-October, mostly at Aster and Rabbitbrush). Spring specimens tend to be faded and frazzled, and the timing, numbers and condition all suggest that adults hibernate. We tested this by looking for pollen of autumn Composites on spring specimens, but identifying Composite pollens to genus is very difficult. We also tried marking large numbers of fall animals, but got no recaptures in spring. The timing implies that if the spring butterflies are descendants of the fall ones, they would have to develop under snow! It has also been suggested that there is altitudinal migration. The species is certainly equipped for that, but the timing of flight at different altitudes does not particularly support the idea. The hosts are perennial grasses; preferences are unknown.

Hesperia lindseyi

admin — Sun, 28 May 2006 18:08:55 +0000

Our populations have been named as a weakly-distinguished subspecies, H. lindseyi eldorado. An uncommon butterfly largely restricted to serpentine grassland, usually in places where there is a big display of Clarkia blossoms in late spring. This species is often sympatric with H. colorado, which it strongly resembles, but both colorado entities (q.v.) in our areea fly later in the year--one of them, much later.

Adults fly low, near the ground, and often sit on bare ground. They are particularly likely to nectar at large yellow Composites like Wyethia and Balsamorhiza, but visit many other flowers too. Flight period May-early July. Larval host plants assumed to be native perennial grasses.

Hesperia nevada

admin — Sun, 28 May 2006 18:08:54 +0000

In our area a high-altitude species, generally found in cold, windwept sites where males hilltop. Both sexes visit puddles and can often be seen on the wet soil adjacent to melting snowbanks. At Donner confined to the east end of the pass; on Castle and Basin Peaks and on rocky knobs along the ridge in between. This species appears to have decreased in abundance in recent years and is no longer seen every year on the transect. It usually flies in July but there are a few records as late as September. The hosts are presumed to be perennial bunchgrasses. Adults have been found on flowers of pink dogbane and various composites.

Hylephila phyleus

admin — Sun, 28 May 2006 18:08:53 +0000

California's most urban butterfly, almost limited to places where people mow lawns. Its range extends to Argentina and Chile and it belongs to a large genus which is otherwise entirely Andean. Its North American range may be quite recent. Here in California, the oldest Bay Area record is only from 1937. At any rate, it is multiple-brooded, and appears to experience heavy winter-kill in most places; scarce early in the season, it spreads out from local places where it survived, gradually reoccupying most of its range by midsummer and achieving maximum abundance in September and October. It occasionally colonizes upslope to about 3000' in the Gold Country but does not seem to survive the winter; strays have been taken to 7000' and on the East slope.

Breeds mostly on Bermuda Grass (Cynodon dactylon), which despite its name is native to the Mediterranean region; probably on other turf grasses as well, including the native Distichlis spicata, which is a Hylephila hostplant in Peru and Chile! Adults swarm over garden flowers--Lantana, Verbena, Zinnias, Marigolds, Buddleia, etc., etc. and in the wild are quite happy with Yellow Star-Thistle.