We’re BACK! Our winter jackets are packed away for the year, our layers are getting lighter, and the bugs are out in full force already. Spring seems to take its time in Montana, but this year feels like it erupted through a wall like the Kool-Aid man. This bug season, we’ve created a dedicated email to send your bug requests, so get out there, take some pictures of arthropods in action, and send them to bugid@missoulabutterflyhouse.org! Happy buggin’!

Header Photo: Milbert’s Tortoiseshell (Aglais milberti). Sal Culotta, April 1st, 2024. St. Ignatius, MT.

Checkered or Becker’s White

Pontia sp.

Without a ventral (underside) view of this butterfly, we were unable to decide if this is a Becker’s White (Pontia beckerii) or a Checkered White (Pontia protodice). Both can be found in this general area at this time of year, in open habitats in the western United States and southern Canada and are often associated with plants in the mustard family. We typically see two broods of these Pontia species each year, and adults take wing throughout spring, summer, and early fall (though they are most abundant in early spring).

Deb Hoagland, April 1st, 2024. Missoula, MT.

Scarce Infant Moth

Leucobrephos brephoides

This early-season moth is a member of the Geometridae, a large moth family with over 23,000 described species. Geometer moth larvae are well-known and often recognized as “inchworms” for their distinct method of locomotion. While many caterpillars have prolegs (false legs) along the length of their abdomen, inchworms only have a single pair at the very end, which results in a jerky movement, allowing them to “inch” along.

Klara Briknarova, March 18th, 2024. Condon, MT.

California Tortoiseshell

Nymphalis californica

California, Compton, and Milbert’s Tortoishells can be found in our area and are generally smaller than the Mourning Cloak. The California’s brightly colored dorsal (upper) side of the wings is opposite to their ventral (under) side, which looks more like a dead leaf. The ventral side can look similar to a Comma’s but they lack the white “comma” on the hindwing or the sharp “ins and outs” along the wing edges. Caterpillars feed on various species of wild lilac (Ceanothus). California tortoiseshells stick mainly to the west, but sometimes stray to the midwest and east after population irruptions.

Glenn Marangelo, March 17th, 2024. Western Montana.

Skwala Stonefly

Skwala sp.

As our friends at the Salmonfly Project say, “Some people call it tax season… we call it Skwala season.” The early emergence of Skwala and the rest of the stoneflies in the family Perlodidae has earned them the nickname “springflies.” A sure sign to get on the river before we’re hit with runoff.

Morgan McNeill, April 2nd, 2024. Missoula, MT.

Compton Tortoiseshell

Nymphalis l-album

Compton’s tortoiseshell is the third member of the “Tortoiseshell trifecta” and another hardy Montana butterfly that spent the winter hibernating in its adult stage. It will emerge from hibernation long enough to mate and lay eggs before it dies; like many of our other early-season butterflies, we will see its offspring again in late summer and early fall.

Glenn Marangelo, March 17th, 2024. Western Montana.

Hunt’s Bumblebee

Bombus huntii

This handsome bumble is found across Western North America, east to Manitoba, and south to Central Mexico. She is found in desert scrub habitats, prairies, and meadows in her northern climes. In her southern range, she is found in high-elevation pine forests, including those near the peaks of volcanoes. Like many bee species, Hunt’s Bumble Bee has experienced some population decline, but it is still one of the more common species encountered in this region.

Sal Culotta, April 1st, 2024. St. Ignatius, MT.

Western Honeybee

Apis mellifera

The honey bee was one of the first domesticated insects and is the primary species beekeepers keep for honey production and pollination services. Thanks to their domestication, they can be found on every continent except Antarctica and are the most critical agricultural pollinator worldwide. These insects are “eusocial,” creating colonies with a single fertile female (queen), tens of thousands of non-reproductive females (the workers), and a small number of fertile males (or drones). The average population of a healthy hive in midsummer may be as high as 40,000 to 80,000 bees.

Carolyn Taber, April 2nd, 2024. Missoula, MT.

Furry Snake Millipede

Ophyiulus pilosus

Millipedes and centipedes both have many legs, but they have some key differences. Millipedes are slow-moving, have two pairs of legs on most segments, and are harmless decomposers. Centipedes are fast, venomous predators with one pair of legs per segment. 

Also known as the Eurasian millipede, this is an introduced species native to and widespread across Europe. These millipedes are probably throughout the Pacific Northwest, especially in urban and residential areas, but their distribution is poorly documented.

Glenn Marangelo, April 7th, 2024. Missoula, MT.

Isabella Tiger Moth

Pyrrharctia isabella

P. isabella caterpillars, also known as Woolly Bears, are common throughout North America at lower elevations and feed on a wide variety of plants, including grasses, asters, birches, clover, corn, elms, maples, milkweed and sunflowers. The caterpillars have a remarkable capability to withstand freezing temperatures thanks to a special “antifreeze” (glycerol) in their body. In spring, they will pupate within cocoons made from their hairs and emerge as the lesser-known adults.

Stacy Carr-Poole, April 10th, 2024. Missoula, MT.

Syrphid Hoverfly

Lapposyrphus sp.

The stripes may alarm you, but don’t worry! That’s not a bee or wasp you’re looking at—although they’d like you to think you are! Syrphid flies are masters of mimicry; they hover near flowers to consume nectar and pollen and often fool passersby into thinking they’re equipped with a stinger. While the adults are harmless, the larvae can be formidable—but only if you’re an aphid, the preferred food of this genera’s offspring.

Sal Culotta, March 20th, 2024. St. Ignatius, MT.