When Amy Hendricks went outside to secure her new patio umbrella from Monday’s gusty winds in Farr West, she took a moment to admire her apple tree in bloom. Then she saw something in the leaves.

“At first, I thought maybe I’m not looking at this right,” she said. “I just stared at it for a moment, then you’d see flutters here and there, and all of the sudden you could tell it was just full."

Full of butterflies, that is. Hendricks said it seemed there was at least one butterfly per bloom — and they were most likely painted ladies, which are half-dollar-sized orange and brown insects. This year’s painted lady migration is the largest since 1991, with large numbers of the butterflies seen across the Intermountain West, said Christy Bills, an entomologist at the Natural History Museum of Utah.

Utahns across the state are seeing an unusual number of these little bugs, fluttering in the foothills or in parks or yards, or stopping briefly on their journey north to drink nectar from weeds and flowers. (Or as yellow splatters against windshields and front grills.)

They seem ubiquitous thanks to a wet winter in the deserts of Mexico and southern California, where they stay for the colder months. The rain meant more plants, which meant more food for the insects, so more survived to make the annual trek north.

Bills said there’s no way to know how many painted ladies are making the journey, but some estimate at least a billion are sojourning this year.

These butterflies are easy to spot because there are so many of them, Utah State University assistant professor Zachariah Gompert said. Through sheer probability, if you see a medium-sized, orange-ish butterfly right now, it’s likely a painted lady.

Another way to tell them apart from their local cousins, such as the American lady butterfly: These bugs are on a mission.

While butterflies that stay in Utah might bop leisurely from flower to flower, searching for a host plant on which to lay eggs, the painted ladies flutter past fast. They’re trying to get where they’re going — while they do stop occasionally to eat or lay an egg. Adult painted ladies only live a few weeks and lay eggs during the migration so their offspring can continue the journey.

In this case, to the northwestern United States and southern Canada, Bills said.

Joseph Silverzweig was gardening with his family members in Murray recently when they looked up to see dozens of painted ladies flying overhead, heading from the south end of the Salt Lake Valley to the north.

“They weren’t thick in the sky, but they were everywhere,” he said. And they were pretty, he added.

That behavior is typical, Bills said. Painted ladies are solitary insects and don’t migrate in swarms. If you see a lot of them together, it’s just because they’re generally all trying to get to the same place.

Gompert said he expects Utahns will see painted ladies throughout the summer and possibly into the fall, though he said their numbers might peter out in the coming months. That’s because while some of these insects will choose to stay here, lay eggs and usher in a new generation, many will move on.

While the abundant painted ladies are the product of a good, wet weather down south, both Gompert and Bills said with the climate warming, it’s unlikely Utahns will experience a migration like this again anytime soon. A migration this large already was rare, Gompert said.

And it underscores the sad reality for butterflies (and insects) generally, whose populations have been declining severely due to a lack of food sources, habitat destruction, pesticides and climate change, Bills said.

Without pollinators like bees and butterflies, recent research shows, ecosystems collapse.

“I want to tell people we have a super serious problem, and, yes, we can do something,” Bills said.

To help these insects, plant pollinator-friendly plants in your yard, such as azaleas, cosmos and marigolds; decrease the amount of land dedicated only to lawns, and don’t use pesticides.

Painted ladies, in particular, aren’t picky and will eat most plants; they really like thistle and dandelions.

“As much as this is super exciting, and I hope people go outside and enjoy it," Bills said, “I hope people realize that we have wonderful butterfly neighbors that we can be better hosts to, make our lives richer.”