Art Shapiro's Butterfly Site - Hesperia

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.