Butterflies of the Month
Okanogan County is the largest county in Washington state and is famous for its diverse wildlife and plant life. However, not many people realize that this county, especially the Sinlahekin Wildlife Area, is also a hotspot for butterflies.
Out of the 155 butterfly species in Washington, 124 are found in Okanogan County. Remarkably, 92 of these species can be spotted in and around the Sinlahekin Wildlife Area, which is about an hour's drive northwest of Omak.
Milbert’s Tortoiseshell Butterfly
Aglais milberti
"Milbert’s Tortoiseshells are very colorful butterflies, at least when you get to view the dorsal side of their wings as they are flying around or perched with wings spread. They have dark narrow borders on both the forewings and hindwings with blue spots within this border on the hindwings. Interior to this narrow outer border is a wide band of very striking bright yellow-orange. The wing color next to the body is a dark brown with patches of orange on the forewings. With their wings spread, they range in size from about 1.3 inches to 2.4 inches. Adults live for about 10 days. There can be up to 3 broods in a season.
Milbert’s Tortoiseshells are similar to the Mourning Cloak in two ways: they overwinter as adults & when a Milbert’s Tortoiseshell rests with its wings closed they appear to be a previous year’s dried leaf or vegetation and are difficult to see."
"Nettles, often called 'Stinging Nettles,' are the larval host plant for Milbert’s Tortoiseshell butterflies. Eggs are laid in clusters, and the caterpillars will be clustered together in a web on the host plant. The adults’ nectaring plants include thistle, aster, and other flowering varieties.
Watch for Milbert Tortoiseshells in riparian areas where nettles occur.
A tip for butterfly enthusiasts is to look for butterflies in wet or muddy areas along streams or after a rain where they are getting salts by 'mud puddling' or, as Caitlin LaBar calls it, a 'Puddle Party.' There can be a multitude of species and individuals at these locations."
— Dale Swedberg | Local Naturalist and Retired Manager of the Sinlahekin Wildlife Area
Painted Lady Butterfly
Vanessa cardui
"Nearly everybody has heard of the amazing migrations of the Monarch butterflies. But there is another butterfly that is a phenomenal migrator – Painted Lady butterflies. Painted Lady butterflies are found throughout the world. In the Western U.S. they begin their migration in the Southwest and can fly as fast as 30 mph at 6-12 feet above ground traveling up to 100 miles per day, thus they can reach more northern areas well ahead of Monarchs. I have seen Painted Lady butterflies migrating through the Sinlahekin and Chiliwist Wildlife Areas and they definitely look like they are on a mission! I found them very difficult to capture as they seemed to rarely land and only momentarily.
Their migration and numbers observed in their northern range seems to be tied, to some degree, to large population emergence/explosion in the southwest based on rainfall and good growing conditions for vegetation. Mass migrations of Painted Lady butterflies have been so thick that they literally cover windshields of cars driving through them. In fact, Interstate 5 (I-5) in Southern California was closed in 1992 due to the abundance of butterflies creating dangerous driving conditions."
"Thistles are the larval plant host of Painted Lady butterflies, in particular the caterpillars use the native “wavy-leaf thistle”, but will use non-native thistles as well. They nectar on dandelion, rabbitbrush, Canada thistle, osier dogwood, and chokecherry - to name a few plants.
Painted Lady butterflies do not overwinter in the Okanogan or anywhere it freezes."
— Dale Swedberg | Local Naturalist and Retired Manager of the Sinlahekin Wildlife Area
