They may start as pests, but don’t squish ’em; you’ll enjoy watching what they become

Among the most striking and recognizable butterflies of Northwest Washington are the swallowtails, a family of large-winged insects with distinctive tiger-stripe markings and a namesake “tail” that extends from their bottom wing.

Both the Eastern and Western tiger swallowtail and the pale swallowtail are found in Washington state. Both are common from May to September, flitting from flower to flower in search of nectar.

“To me, what comes to mind when I see a butterfly is that I’ve created a space in my garden that’s welcoming to that species,” said Beth Chisholm, community horticultural coordinator for the Washington State University Whatcom County Extension.

“But kids? They’re just fascinated. They want to catch it and see it close. They’re so big and beautiful and full of color. Kids just light up when they see one. They typically chase it and it flutters away.”

Holly Roger, with the outdoors education group Wild Whatcom, said her students are amused when they see butterflies exhibit a common behavior called puddling.

“I think that’s the funniest thing about butterflies, seeing them on the trail and watching for them messing around in puddles;’” Roger said.

If you want to see butterflies in summer, however, don’t kill the caterpillars in spring, Chisholm said.

“A lot of people think at the caterpillar stage that it can be a pest, and a lot of people just want to squish the creepy-crawly bugs,” Chisholm said. “But these have a full life cycle.”

Parents can help by teaching children how to create a good garden habitat and not using pesticides, Chisholm said. The Extension program operates a pollinator demonstration garden in the summer at Hovander Homestead Park near Ferndale. For children and parents who are interested in learning more about insects, Chisholm recommends bugguide.net.

“It’s a great resource for the novice,” she said.

Tiger swallowtails have a wingspan of 2 3/4 to 4 inches, yellow wings with black tiger stripes and spots of blue and orange on their hind wings. They frequent woodlands near rivers and streams, wooded suburbs, parks and roadsides, according to butterfliesandmoths.org. As caterpillars, they favor leaves of cottonwood, aspen, willow, wild cherry and ash. Adults take nectar from a variety of flowers, including nectar from many flowers including thistles, abelia and zinnia.

Tiger swallowtails usually have one or two “flights,” or reproduction cycles, each spring and summer. They’re not usually considered an endangered species.

Pale swallowtails resemble a smaller, pale yellow tiger swallowtail, with a wingspan of 2 1/2 to 3 1/2 inches. They’re found in open woodlands and along streams. Caterpillars like the leaves of trees and shrubs such as cherry and ash. As adults, they sip flower nectar.

Pale swallowtails usually have one “flight” from April to July. They’re not usually considered an endangered species.

This story was originally published May 23, 2017 at 12:46 PM with the headline "They may start as pests, but don’t squish ’em; you’ll enjoy watching what they become."