While you can always visit MBHI to witness an incredible array of butterfly diversity, Western Montana is currently giving us a run for our money. July is an opportune time to catch adults on the wing, as many butterflies’ phenological periods overlap during this time. This week even features our first Monarch caterpillar sighting, which means adults can’t be far behind.
Header Photo: Gillett’s Checkerspot (Euphydryas gillettii). Kristi DuBois, July 5th, 2024. Rogers Pass, Lewis & Clark County, MT.
Common Loopwing Aphideater
Lapposyrphus lapponicus
Syrphid Flies are great at making you think you’re dealing with a wasp, hornet, or bee. Often seen hovering near or perched on flowers, the adults feed on pollen and nectar. Depending on the species, larvae feed on decaying plant or animal matter and other insects (namely aphids and leafhoppers). Hoverflies are also important pollinators of various wild plants and crops worldwide. While different species may show a preference for specific flowers, they appear to prefer white and yellow colored flowers.
Misty Nelson, July 5th, 2024. Anaconda-Pintler Wilderness, MT.
Melissa Blue (Mating Pair)
Plebejus melissa
This striking blue butterfly is one of the more widespread blue species in the West, inhabiting plains, prairies, and the Intermountain West from southern Canada to Baja California. They prefer dry, open clearings and forest edges with plenty of sun. Adults lay eggs on or near their host plants, usually Lupine species but occasionally other plants in the pea family. They overwinter in their egg stage or as an early instar (freshly hatched) and emerge in the early spring. We experience two broods each year, meaning we will likely see this pair’s offspring in the fall.
Kelly Dix, July 5th, 2024. Skidway Campground, Broadwater County, MT.
Cat-faced Orbweaver
Araneus gemmoides
Many people refer to all orb weaver spiders as “Cat-faced Spiders” or “Barn Spiders,” but this species is THE definitive Cat-faced Spider, also called the Plains Orbweaver or Jewel Spider. Their identifying characteristic features a fine white line crossed by two shallow white V’s on the front abdomen. As we move into late summer and fall, orb weaver females become more noticeable as they grow and prepare to lay eggs. They stick around until the first hard freeze, at which point the adults die off. Then, it’s up to the egg sac she leaves behind to usher in the next generation in the spring.
Adeline Flegel, July 17th, 2024. Lower Rattlesnake, Missoula, MT.
Mountain Lady Beetle
Coccinella monticola
Many assume there are only a handful of ladybug species – but in reality, there are over 6,000 currently known to science and 480 known species in the United States. Differentiating the size, shape, and placement of spots and facial markings is crucial for identification, and some species are so similar they are nearly impossible to tell apart. The Mountain Ladybug, however, has distinct oblong markings on its wing covers: two on each elytra and a central oblong marking just behind the thorax. This species is widespread across the mountainous regions of the west and can be found throughout Canada – even as far as the Yukon. Mountain Ladybug, indeed.
Brenna Shea, July 10th, 2024. Rock Creek Confluence, Clinton, MT.
Poplar Borer
Saperda calcarata
The species name for this medium-sized boring beetle, calcarata, means “having a spur” and references the small, pointed spurs on the tips of its hardened forewings (elytra). here at MBHI, we have another species that bears the name calcarata: Eurycantha calcarata, the thorny devil stick insect. However, the two “spurred” insects are not closely related. Thorny devils are phasmids (stick insects), while the poplar borer is a beetle. The poplar borer larvae are notorious forest pests, boring their way into aspen and cottonwood trunks and causing considerable damage. They range throughout North America, as far north as southern Canada.
Sal Culotta, July 14th, 2024. St. Ignatius, MT.
Bluet (Female)
Enallagma sp.
As their name suggests, Bluets are striking blue damselflies commonly found near ponds and other still bodies of water. Like all odonates (from the order Odonata, which includes damselflies and dragonflies), they begin their life in an aquatic setting, hunting other insects and even small fish. As adults, their aerial hunting skills are unparalleled. Odonates were some of the first flying insects and retained their primitive flight muscles, allowing them to move each wing independently. Combined with their gigantic, well-developed eyes, they are formidable predators (and challenging to capture in photos!).
Morgan McNeill, July 12th, 2024. Deer Lodge, MT.
European Skipper
Thymelicus lineola
The European skipper (known across the pond as the Essex Skipper) was accidentally introduced to North America in 1910 in Ontario, Canada. They have since become well-established in the east and, more recently, in the west (Colorado, Idaho, Montana, and British Columbia). Their westward expansion is likely due to egg relocation in hay shipments. Their larvae feed on a range of grass species, and adults lay their inconspicuous eggs by the dozen on a single sheath. The European Skipper is the only known North American skipper species to overwinter in their egg stage.
Brenna Shea, July 10th, 2024. Rock Creek Confluence, Clinton, MT.
European Ground Beetle
Carabus nemoralis
These European transplants, introduced roughly 150 years ago, are now widespread in their North American range. Flightless and nocturnal, they prowl gardens, yards, and open, wooded areas for soft-bodied invertebrates. Have a slug problem? These guys can help you out! They are easily observed on pathways and bare patches of soil by flashlight and porchlight from April until fall and occasionally during the day to get their picture taken. The metallic-purple rim that borders their elytra and thorax is certainly photo-worthy!
Shelby Fisher, July 14th, 2024. Missoula, MT.
Nuttall’s Blister Beetle
Lytta nuttalli
Lytta is a diverse group of blister beetles, with 47 species in North America and the most diversity occurring in the West. As their name suggests, blister beetles can produce a toxic compound, Cantharidin, that they secrete when threatened. Cantharidin is a fatty terpenoid that causes painful, blistering reactions to human skin and is poisonous in large doses. Who in their right mind would ever consume such a substance, you ask? There are reports that Cantharidin has an aphrodisiac effect; in fact, male blister beetles will produce small amounts of the toxin and present them to a female as a copulatory gift. She will use the gift to cover her eggs as a blanket of protection against predators. But maybe don’t try it on your next date.
Kelly Dix, July 5th, 2024. Skidway Campground, Broadwater County, MT.
Monarch
Danaus plexippus
A few intrepid community scientists spotted this iconic caterpillar at a milkweed patch at Maclay Flats. Monarch caterpillars feed exclusively on milkweed (Asclepias spp.), and the chemicals the plants produce make both larvae and adults extremely distasteful to predators, as advertised by their bright “warning colors.” Monarch sightings in western Montana are relatively uncommon but not unheard of. We find ourselves at the northern edge of their migratory range; adults fly through any time from mid-June to mid-August to lay eggs. Monarchs west of the Rocky Mountains migrate to southern California to overwinter; though the species as a whole is considered at risk, this western population is in steep decline, with millions of individuals vanishing over less than half a century. Sightings like this one are crucial for researchers tracking their numbers and overall fitness.
William Schlegel, July 11th, 2024. Maclay Flats, Missoula, MT.
Field Crescent (mating pair)
Phyciodes pulchella
These small to medium-sized butterflies range across high elevations in the West, from central Alaska and the northern Yukon all the way to southern California, Arizona, and New Mexico. Their range abruptly ends at the eastward edge of the Rocky Mountains. In western Montana, adults are on the wing from June to August. They are widespread in the mountainous western half of the state, often found in alpine prairie, forested foothills, and mountain meadows. Caterpillars feed on various asters—adults nectar from an even wider variety of flowers.
Kelly Dix, July 5th, 2024. Skidway Campground, Broadwater County, MT.
Clouded Yellow
Colias sp.
This butterfly wouldn’t sit still long enough to get a close-up, so we can only confirm that they belong to the genus Colias, the clouded yellows (or sulphers). All members of this genus are migratory to some degree; some species move up and down in elevation in response to temperature and plant growth. Others undertake significantly longer migrations, traversing north to south across the United States in the fall along with many other migratory animals.
Brenna Shea, July 10th, 2024. Rock Creek Confluence, Clinton, MT.
