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| Umber Skipper butterfly (Poanes melane) - perched on Purple sage |
July is butterfly month in Southern
California, and this is a good year. We
are fortunate in our bounty; over 20 butterfly species routinely visit local
home gardens. For more on attracting these
‘jewels of summer’ see: http://mother-natures-backyard.blogspot.com/2012/06/butterfly-gardens.html
Common to California gardens are the
small orange/gold, brown and black butterflies known collectively as the
Skippers. The Skippers, in the family Hesperiidae, are best viewed as
‘sisters’ to the rest of the butterflies [1].
They generally have short, stocky, hairy bodies, a large head with
hooked antennae, relatively small pointed wings and a rapid ‘skipping’ flight
pattern. The
green caterpillars, which have a large head, are also distinctive. There are at
least 3500 Skipper species world-wide (about 250 native to North America). We discussed one group – the Duskywing
Butterflies (genus Erynnis) – previously
(http://mother-natures-backyard.blogspot.com/2015/05/duskywing-butterflies-genus-erynnis.html).
The sub-family Hesperiinae - the folded-wing
skippers – is well-represented in California. This is the largest Skipper
sub-family, with over 2000 described species world-wide. Unlike the Duskywings, this group perches
with its wings either folded or with the hind wings flat and the forewings
partially closed, giving the appearance of double wings. Hesperiinae
larvae (caterpillars) feed on grasses and sedges, hence the common name ‘Grass
Skippers’. A locally common representative
is the Umber Skipper, Poanes melane, which frequents many gardens
containing native or non-native grasses and sedges (even lawn and weedy
grasses).
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| Umber Skipper butterfly (Poanes melane) - on dried Grindelia |
Umber
skippers are relatively small – about 1 ¼ inches (3.2 to 3.5 cm) across. But they do perch regularly, allowing you to
view them even without binoculars. If you’re patient, you can take good
photographs of Umber Skippers. Once you recognize them, you’ll realize just how
common they are in our area’s gardens.
Umber
skippers range from western California (west of the Sierras) into Baja
California, and the highlands of Mexico and Central America. The California type (ssp. melane) is limited to western CA (from
Northern CA [Monterey County] south to the Mexican border) and Baja California,
Mexico. The range of Poanes melane appears to be expanding
northward in California, perhaps due to the availability of grass lawns and
possibly due to climate change. [2, 3]
Umber Skippers were apparently
unknown in San Diego County until the 1930’s [4].
Poanes melane melane was proposed as a sub-species by none
other than William Henry (W. H.)
Edwards, in 1869. Edwards was a famous butterfly expert of his time. He wrote the three-volume Butterflies
of North America (1868-1897), called "one of the most important
entomological publications of the 19th century." [5] Edwards was particularly interested in
morphologic (physical) differences within a species and the role these play in
the development of new species. Poanes
melane certainly
demonstrates morphologic variability within its range.
We were surprised by the limited research on the
taxonomy and natural history of Poanes
melane. For such an interesting
butterfly, relatively little is known about its classification and life
ways. This species presents a ripe
field of inquiry for a graduate student interested in Southwestern butterflies.
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| Umber Skipper butterfly (Poanes melane) - perching male |
Umber skippers are best known (and named for) their
most obvious feature – their overall umber color. Among local folded-wing skippers, this is the
darkest appearing; the rest are either more orange or paler. The
males are said to be smaller and darker than the females, but we can’t claim to
tell the difference reliably.
We do see quite a bit of variability in our own
gardens (see below). This may in part be
due to sexual dimorphism; we also suspect that individuals lose some of their
bright coloring as they age. The
brightest Umbers are most common early in the season. The darker ones are more frequent later; these
have often lost much of their juvenile ‘hairiness’ as well (see below). They blend in quite well with drying
foliage.
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| Umber Skipper butterfly (Poanes melane) - dorsal side |
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| Umber Skipper butterfly (Poanes melane) - doral side |
When viewed more closely, the upper (dorsal) side is
primarily umber brown, although sometimes the color appears almost
black-brown. The forewing, which is
often easiest to view, has a line of three small lozenge-shaped patches near
the edge. These are usually a bright yellow-orange, but may be almost white.
They are quite distinctive and easy to spot.
There are also a series of larger, yellow-orange splotches nearer the
body. These form an irregular line or
band. The hind wing has a light,
yellow-brown band, which is distinctive in this species. The narrow wing fringes are a pale tan (see
above).
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| Umber Skipper butterfly (Poanes melane) - ventral side |
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| Umber Skipper butterfly (Poanes melane) - ventral side |
The lower (ventral) side is often easy to view when Umber
skippers are feeding. The ventral side wings are lighter, with an umber
background and paler orange (to white) blotches. The blotches form a distinctive v-shaped band,
which is often described as unique to this species.
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| Umber Skipper butterfly (Poanes melane) - close up, ventral |
The antennae are approximately 1/3 the body length, spreading
out and slightly forward; they have the slight hook at the end that is typical
for Skippers. The entire body is quite
hairy. The hairs atop the head are
umber; the ‘face’ and area around the eyes is white (see above). The hairs on the underside of the body are often
also gray-white.
For
more good pictures of Poanes melane in all stages see:
- http://nathistoc.bio.uci.edu/lepidopt/hesper/umber.htm
- http://socalbutterflies.com/hesperiidae_html/umber.htm
- http://calphotos.berkeley.edu/cgi/img_query?stat=BROWSE_IMG&where-lifeform=Invertebrate-Insect&where-taxon=Poanes+melane&title_tag=Poanes+melane
- http://bugguide.net/node/view/9790/bgimage
- http://butterfliesofamerica.com/poanes_m_melane.htm
Umber
Skippers can be seen anytime from spring (usually March) through fall
(October), but they are most common locally in the hot, dry days from June
through September. They have several
broods a year [4], one in spring and another in late summer/fall.
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| Umber Skipper butterfly (Poanes melane) in garden |
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| Umber Skipper butterfly (Poanes melane) - nectaring on Yarrow |
From
our experience, Umbers are common butterflies in the Los Angeles Basin. In the wild, they live in shaded canyons in
the foothills and Oak woodlands. They can also be found in grassy areas in
Preserves, parks and gardens, often near water.
We were surprised that Umbers are uncommon in Orange County suburbs [4]. This has not been our experience; we see them
regularly in western Los Angeles County, particularly in gardens with native
plants.
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| Umber Skipper butterfly (Poanes melane) - nectaring on Purple sage |
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| Umber Skipper butterfly (Poanes melane) - trying to get to nectar in Penstemon flower |
Adult
Umber skippers feed on floral nectar, primarily from plants in the Sunflower (Asteraceae) and Mint (Lamiaceae) families in our gardens. We commonly see them on Yarrow, Asters,
Gumplants, Goldenrods, native Sages (Salvias), mints and Monardellas. It’s not unusual to see several Umbers on a
single flowering plant – or Umbers nectaring with Fiery (Hylephila phyleus) or other
Skippers. Umbers are quite tenacious in
their quest for nectar (see above); we’ve seen them hanging upside-down – even
entering tubular flowers like the Penstemons.
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| Umber Skipper butterfly (Poanes melane) - courtship behavior |
When not nectaring, males can be
seen perched near grasses, waiting for receptive females. We have observed female Umbers rapidly
circling a perched male, a behavior that’s easier to observe than to photograph.
Males will also dart out to inspect potential mates. We’ve tried photographing the
Umber’s mating ritual many times – with less than optimal results (above). The perched individuals appear to be male;
the circling individuals appear to be larger and brighter females. We’ll continue to observe and update with
new insights into Umber behavior.
We’ve also seen Umbers chasing off
other individuals, mostly Umber and other Skippers, in what we assume to be
territorial behavior. Several to a
handful of individuals will also sometimes chase upward in a spiraling pattern.
We’re not sure whether this represents courtship or other activity. Perhaps someone with more knowledge of Skipper
behavior can enlighten us?
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| Umber Skipper butterfly (Poanes melane) - in flight |
Larval
food sources are a range of native and non-native grasses and sedges. Raymond Barbehenn [6] suggests that the only
limitation may be the toughness of some grass species. Caterpillars did not grow on the tougher
grass species, such as Deer grass (Muhlenbergia
rigens), which they may not be able to digest. Umber larvae have been observed eating a wide
range of common lawn and weedy grasses including tufted hairgrass
(Deschampsia caespitosa), Bermuda grass (Cynodon dactylon), California brome
(Bromus carinatus), and sedges.
Females
likely lay individual eggs on the undersides of grass blades. The caterpillars eat the grass/sedge
leaves. They hide from predators by
constructing shelters made of rolled leaves.
The caterpillars are pale green with a dark gray or brown head. For photos of eggs and caterpillars see:
We
hope we’ve inspired you to search for – and observe – this interesting Skipper
species. There’s much still to learn
about this little butterfly. Perhaps you’ll
discover something new – right in your own backyard!
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| Umber Skipper butterfly (Poanes melane) - nectaring on Woodmint |
____________________
1. Art
Shapiro’s Butterfly Site - http://butterfly.ucdavis.edu/butterfly/common/Skippers
- http://nathistoc.bio.uci.edu/lepidopt/hesper/umber.htm
- Calhoun,
John V. (2013). "The
Extraordinary Story of an Artistic and Scientific Masterpiece: The
Butterflies of North America by William Henry Edwards, 1868-1897"
(PDF). Journal of the Lepidopterists’ Society 67 (2): 67–110.
6. Host
plants of Poanes melane - http://www.biodiversitylibrary.org/page/41139192#page/404/mode/1up
For more S. California insects see: http://mother-natures-backyard.blogspot.com/2016/07/insect-postings-mother-natures-backyard.html
We encourage your comments below.
If you have questions about Skipper butterflies or other gardening
topics you can e-mail us at : mothernaturesbackyard10@gmail.com
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