Tuesday, August 4, 2015

Late-season Butterflies

The butterfly season is winding down but there are still several species flying in the Northwest, especially up in the mountains.  I have heard reports of large numbers of Great Spangled Fritillaries (Argynnis cybele) flying in the mountains north of Ellensburg and have personally observed most of the following species recently between Cougar and the Windy Ridge Viewpoint east of Mount St. Helens, as well as the area west of Indian Heaven Wilderness.
Look for these little beauties when you're out in the woods hiking and camping over the next few weeks:
Woodland Skipper - Ochlodes sylvanoides
This little orange jewel is quite common in most locations throughout the Pacific Northwest, flying from June until the first hard frost, usually peaking in August.  The larvae feed on various grasses.
Woodland Skipper - Ochlodes sylvanoides
Clodius Parnassian - Parnassius clodius
Mountain Parnassian - Parnassius smintheus
These are the large white gliders seen in sunny forest edges and meadows in mid-summer. Their flight is winding down right now but they are still out in fair numbers at higher elevations.  Look for Clodius Parnassians on the west side of the Cascades and Mountain Parnassians on the east side. They are easily distinguished by their antennae: Clodius' are solid black and Mountain's are checkered black and white.  Other diagnostic characteristics include the two red spots on the hindwing (the lower spot is usually slightly smaller than the upper on Clodius, and slightly larger than the upper on Mountain) and the amount of scales on the forewing (Clodius forewings have fewer white scales around the edges so appear more clear, while Mountain Parnassians are mostly white). Clodius Parnassian larvae feed on bleeding hearts and Mountain Parnassian larvae feed on various stonecrops (Sedum species).
Clodius Parnassian (above) and Mountain Parnassian (below)
Pine White - Neophasia menapia
Larvae of these butterflies feed on the needles of pine and occasionally Douglas-fir trees.  Females usually stay high up in the trees, occasionally coming down to nectar on thistle, rabbitbrush, and other late summer flowers.  In years with high population numbers, these butterflies create the appearance of snow in the forests, fluttering high around the trees and floating down to nectar on flowers.
Pine White - Neophasia menapia
Purplish Copper - Lycaena helloides
Mariposa Copper - Lycaena mariposa
Purplish Coppers are widespread and common and usually have multiple generations per year, so are one of the few species seen in late summer.  Their larvae feed on several plant species, mostly in the Polygonaceae family (knotweeds, smartweeds and dock).  Mariposa Coppers are much more localized, restricted to areas where their host Vaccinium species grow, such as huckleberries and wild cranberries.  I love seeing the flashes of coppery purple and frosty brown among the bushes while I'm picking huckleberries this time of year!
Purplish Copper L. helloides (above) and Mariposa Copper L. mariposa (below)
Mormon Metalmark - Apodemia mormo
These little gems should be appearing soon in the dry washes and canyons of central and eastern Washington.  Look for them nectaring on rabbitbrush in areas where their host buckwheats (Eriogonum sp.) grow.  Some good locations are along the Columbia River and at the two viewpoints off I-82 on Manastash Ridge overlooking the Kittitas Valley.  You'll get some puzzled looks from onlookers wondering why you're scampering around the rabbitbrush apparently staring at broken bottles and trash instead of taking pictures of the valley like a sane person!
Mormon Metalmark - Apodemia mormo
Lorquin's Admiral - Limenitis lorquini
This butterfly is tenacious, continuing to fly into late summer in spite of tattered wings and often being so faded it is nearly unrecognizable save for its characteristic flap-flap-glide flight pattern.  Lorquin's Admirals usually peak around the end of June and early July, but I am still seeing them here and there in the mountains.
Lorquin's Admiral - Limenitis lorquini
Great Spangled Fritillary - Argynnis cybele
These are one of the last fritillary species to fly in the summer.  They seem to be nearing the peak of the flight season right now. They are sexually dimorphic, which means the females are colored significantly differently than the males.  Both are very large, nearing 3 inches compared to the ~2 inch wingspan of other fritillaries.  While flying, the females often look more like a Mourning Cloak than a fritillary.  As with other fritillaries, the larvae of Great Spangled Fritillaries feed on violets.
Great Spangled Fritillary (male & female) - Argynnis cybele
Hydaspe Fritillary - Argynnis hydaspe
Coronis Fritillary - Argynnis coronis
Hydaspe Fritillaries are very common in forested areas on both sides of the Cascades.  On the western side, they are usually the only fritillary species flying. Where they fly with other fritillaries, they are often distinguishable on the wing by their deep orange color.  Great Spangled Fritillaries have a similar color but are usually brighter and always larger.  Another late-summer fritillary is the Coronis Fritillary (below). They are more yellowish-orange and appear much lighter in color than Hydaspe in flight.  Larvae of both species feed on violets.  Coronis Fritillaries are known for their seasonal migration, emerging in the sagebrush-steppe of central and eastern Washington in late spring and following the flowers to higher elevations, especially westward into the Cascades.  They are rarely seen west of the Cascade crest, but I observed several of them near Mount St. Helens last week, possibly due to the dry summer resulting in a lack of nectar sources further east.
Hydaspe Fritillary - A. hydaspe (above) and Coronis Fritillary - A. coronis (below)
California Tortoiseshell - Nymphalis californica
Milbert's Tortoiseshell - Aglais milberti
Red Admiral - Vanessa atalanta
These three butterflies may be confused with each other by the casual observer.  Red Admirals usually aren't very common but have had a good year with more local sightings.  Both tortoiseshells are common, primarily in the mountains from the Cascades eastward.  California Tortoiseshells have boom and bust cycles and have had fairly low numbers in recent years. Their larvae feed on Ceanothus species (buckbrush/snowbrush).  Milbert's Tortoiseshells usually have a fairly steady population and are found nearly anywhere their host stinging nettles grow.  Red Admiral larvae also feed on stinging nettle.
California Tortoiseshell (above), Milbert's Tortoiseshell (center) and Red Admiral (below)
Ochre Ringlet - Coenonympha tullia
Common Woodnymph - Cercyonis pegala
These are nearing the end of their flight season but are still popping up occasionally.  Typical of the satyr family, they both have slow, floppy flight patterns and rarely fly more than two or three feet above the ground.  Larvae of both feed on various native grasses.
Ochre Ringlet C. tullia (above) and Common Woodnymph C. pegala (below)