The heat may take its toll on us, but everything else seems to love this sudden onset of summer. Personally, my garden is making up for lost time, and after a plodding start, it is quickly becoming ungovernable. At the very least, the insects are benefitting, and based on the number of submissions we’ve been receiving, they’re thriving all over Western Montana right now.
Header Photo: Elegant Sheep Moth laying eggs (Hemileuca eglanterina). Kristi DuBois, July 5th, 2024. Rogers Pass, Lewis and Clark County, MT.
Modest Sphinx
Pachysphinx modesta
This impressive sphinx moth is found in the northern United States and Canada for a brief period from mid-June to mid-July. From July to November, their offspring bulk up and prepare to overwinter underground in their pupal stage. The name refers to the dark lower portion of the adult wings; when at rest, it appears the moth is dressed “modestly” as though wrapped in a dark scarf or shawl. They are found anywhere their larval host plants grow: poplar, aspen, cottonwood, and willow. With their short lifespan, adults do not feed at all; instead, they spend their time looking for a mate.
David Lorenzo, July 4th, 2024. Clinton, MT.
Small Milkweed Bug
Lygaeus kalmii
This striking little critter is not a box elder bug, but you’d be forgiven for thinking so. As another hemipteran (true bug), Lygaeus kalmii shares several characteristics with the easily recognizable box elder bug; besides their vivid colors, they both have piercing-and-sucking mouthparts and a characteristic “X” shape on their back where their wings cross. Small Milkweed Bug adults feed on flower nectar and milkweed seeds, but if resources are scarce, they are quick to scavenge or even hunt other insects. Those daunting mouthparts are great for sipping nectar but can pierce through a prey item just as easily.
Glenn Marangelo, July 4th, 2024. Missoula, MT.
Two-tailed Swallowtail
Papilio multicaudata
Two-tailed swallowtails are primarily on the wing in Montana in late spring and early summer. They’re the largest of all our western butterflies, with some individuals pushing six inches in wingspan, and unique among them, sporting two “tails” on the hindwings. Males patrol stream courses or open thoroughfares looking for receptive females. The caterpillars commonly feed on chokecherry and ornamental green ash. Like many other swallowtails, the younger larvae resemble bird droppings. The older caterpillars have a bright orange, odorous organ (osmetriums) that can be everted from behind the head when threatened.
Glenn Marangelo, July 4th, 2024. Missoula, MT.
Western Eyed Sphinx
Smerinthus ophthalmic
The Western-eyed Sphinx is a relatively new species; in 2010, researchers separated it from the One-eyed Sphinx (Smerinthus cerisyi). Despite their many shared physical characteristics, S. ophthalmica males can be reliably separated from S. cerisyi by their lack of scalloped hindwing margins and less-contrasting pale wing venation. Recent DNA analysis reveals that the two species show a significant divergence in mitochondrial DNA. The Western-eyed Sphinx ranges across the West Coast, as far east as the Rocky Mountains.
Bodie Lesser-Smith, July 2nd, 2024. Camp Paxon, Seeley Lake, MT.
Western Tiger Swallowtail
Papilio rutulus
The Western Tiger Swallowtail is one of the largest and most recognizable butterflies in our area. They are common in parks and gardens but can also be spotted in cities and suburbs thanks to the popularity of using their host plants (particularly sycamores, but host plants also include cottonwood, birch, elms, willow, alder, and aspen) in urban landscaping. Males often congregate in large “puddling parties” near stream banks or puddles to extract minerals and water from the damp earth. We only see one flight period in this part of their range, and by fall, the new generation of caterpillars will pupate and overwinter in their chrysalids.
Glenn Marangelo, July 4th, 2024. Missoula, MT.
Dimorphic Flower Longhorn Beetle
Anastrangalia laetifica
Could you find a bug with a more descriptive name? The Dimorphic Flower Longhorn Beetle has it all: “Dimorphic,” referring to the sexual dimorphism between males and females (females, like the one shown here, have bright red elytra with four black dots, while the males are entirely black). “Flower,” referring to this beetle’s preferred food source, and “Longhorn,” referring to the prominent antennae that are a feature of all species in the family Cerambycidae (Longhorn Beetles). This species ranges across the northwest, from southern British Columbia to the southern coast of California. Western Montana is the very eastern edge of its northwestern range.
Lisa Cloo, June 30th, 2024. Turah, MT.
Great Grig
Cyphoderris monstrosa
This bulky, formidable creature belongs to the family Orthoptera, along with crickets, katydids, and grasshoppers. Like katydids and crickets, Great Grig males use a scraper-and-file mechanism on their tegmina (hardened forewing) to sing. At dusk, males begin calling to attract mates while repelling potential rivals. The longer a male sings, the higher his fitness (and the likelihood he has a chance to mate). They range throughout the Northwestern United States and Southwestern Canada. They primarily feed on broad-leaved shrubs and the pollen of coniferous trees; but females occasionally consume the wings of a male after mating.
Sarah Capdeville, July 2nd, 2024. Rattlesnake Recreation Area, Missoula, MT.
Leafcutter Bee
Megachile sp.
These small bees readily inhabit “bee hotels” and other natural tunnels in wood or the ground. They construct several cells in each tunnel from the leaf pieces they collect. Each cell will contain a single egg and a store of pollen to feed the emerging larva. Since the female is on her own (they do not work together as a colony), they are usually swamped, making many trips back and forth with pieces of leaves and pollen. Unlike other bee species that collect pollen in pollen baskets on their legs, leafcutters collect pollen in dense hairs on the underside of their abdomen (called scopa), turning their bellies yellow as they gather.
Glenn Marangelo, July 4th, 2024. Missoula, MT.
Striped Sweat Bee
Agapostemon sp.
Striped sweat bees are named for their distinctive striped abdomens, but are also known as “metallic sweat bees” for their metallic blue or green head and thorax. All 44 species in this genus (ranging from southern Canada to northern Argentina) nest in the ground; while they may nest close together – even sharing the same burrow entrance – these bees do not form colonies or divide their labor. Agapostemon females mate in late summer/early fall and overwinter in the ground. In the spring, she will emerge to dig and furnish her brood cells.
Sal Culotta, July 5th, 2024. St. Ignatius, MT.
White-lined Sphinx
Hyles lineata
White-lined sphinx Moths are one of the most abundant hawk moths in North America, having a wide geographic range (from southern Canada into Central America). They occupy open habitats, including deserts, suburbs, and gardens. As adults, they are often mistaken for hummingbirds thanks to their enormous size and rapid wing beating while they feed from flowers. The caterpillars are large and beautiful, with a reddish-orange horn at the rear. Here in MT, the caterpillars overwinter, with adult moths appearing in May. After mating and laying eggs, we typically see the next generation of adults in late summer. This chonky individual is likely a second-generation caterpillar.
Kathy Steen, July 5th, 2024. Missoula, MT.
Snowberry Checkerspot
Euphydryas colon
This checkerspot is so named for it’s larval food source, the snowberry. However, whether or not this species is its own or a subspecies of the variable checkerspot, Euphydryas chalcedona, is up for debate. Some argue that all E. chalcedona north of California should be considered E. colon, but evidence to support these two as separate species is lacking. This species (or subspecies) has a northwestern distribution, from the northern tip of CA into British Columbia, and as far east as Western MT.
Glenn Marangelo, June 29th, 2024. Potomac, MT.
Carolina Grasshopper Nymph
Dissosteira carolina
In flight, these large hoppers may be mistaken for Mourning Cloak Butterflies because of their similar size, bobbing flight, and wing coloring. Carolina grasshoppers are abundant across the U.S. and Canada in all habitats, including roadsides, vacant lots, and gravel quarries. They feed on both grasses and broadleaf herbaceous plants like dandelions. The sharp ridge on top of the head/thorax with one deep cut is a good identifier in combination with other characteristics.
Glenn Marangelo, July 3rd, 2024. Clinton, MT.
