While the weather has shifted in recent days, you don’t need to know the outside temperature to know fall is just around the corner. The spiders in our gardens are getting bigger, and it’s nearly impossible to walk through a patch of grass without flushing a dozen grasshoppers. Second-generation caterpillars are bulking up to overwinter, and before we know it, insect activity will quiet almost entirely. Be sure to get out there while the gettin’s still good!
Submit your bug pictures to bugid@missoulabutterflyhouse.org (and remember to include your name, the date, and the location where you took the photo)!
Header Photo: Six-spotted Orbweaver (Araniella displicata) Steve Parker, August 11th, 2024. Huson, MT.
Pale Snaketail
Ophiogomphus severus
Male dragonflies in the genus Ophiogomphus, otherwise known as “snaketails,” are easily recognized by their club-shaped abdomen and brilliant green coloring. Like all dragonflies, they are highly efficient predators, expertly maneuvering through the air to snatch their unsuspecting prey. With the help of their impeccable eyesight, dragonflies manage to nab up to 97% of the prey they pursue, making them the most effective predators on the planet.
Connie Geiger, August 2nd, 2024. Scratchgravel Hills, Helena, MT.
Dark Firefly
Pyropyga nigricans
Not all fireflies light up the night sky. While we do have some species of glowing fireflies in Montana (though they’re challenging to find), dark fireflies (which do not glow) are relatively common. However, they are easily missed at about 4.5-8mm long. There are 13 described species in the genus Pyropyga, and none have bioluminescent organs. Maybe it’s because they’re not as flashy as their luminous cousins, but there is little info on this genus.
Klara Briknarova, August 4th, 2024. Missoula, MT.
Carolina Grasshopper
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.
Connie Geiger, August 2nd, 2024. Scratchgravel Hills, Helena, MT.
Yellow-headed Cutworm Moth
Apamea amputatrix
Moths can be intimidating insects to attempt to identify, especially ones as cryptic as this cutworm moth. With nearly 12,000 species in the Cutworm Moth family (Noctuidae) alone, there are many species that mimic not only their environment but each other. This species is identifiable by the two very small white dots on the reniform spot. It’s the small, often-overlooked features that distinguish these cryptid moths from each other, but identification becomes less intimidating if you know where and how to look. This species is found throughout North America, and like many cutworm moths, their larvae can be common garden pests that feed on all manner of fruits, veggies, grasses, and more.
Kathleen Ort, August 11th, 2024. Salmon Lake, MT.
Western Sphinx Moths
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. This mating pair shows a phenomenal example of the pale brown phenotype seen in males in prairie populations. Sue found them in the morning, and 10 hours later, they were still there. She notes, “They sure are slow as snails in getting the job done!”
Sue Lowery, August 6th, 2024. Missoula, MT.
Silkmoth Caterpillar
Hyalophora sp.
If you think this Dr. Seuss-looking caterpillar is impressive, wait until you see what emerges next spring. Giant Silkmoths in the genus Hyalophora are some of the largest and most recognizable moths in Western Montana. And while the caterpillar is a great example of “don’t pick it up until you know what it is,” BugGuide notes the following: “The imposing larvae DO NOT sting; however, they do contain toxins & complex proteins in their hemolymph (blood), incl. a strong antibiotic, Attacin. When disturbed, the larvae will “bow up,” thrash from side to side and may release small droplets of hemolymph containing various toxins. […] In some instances, there may be severe reactions (incl. skin irritation, rash, burning & itching, watery eyes, runny nose, and sneezing – extreme reactions may include swelling and difficulty breathing).
Judy Halm, August 10th, 2024. Rogers Pass, Lewis and Clark County, MT.
Bagworm Moth
Family Psychidae
Bagworm moth larvae spend most of their lives inside a “bag” or case. Made of silk and covered with bits of plant material and other debris, they carry it around as they feed and will add to it as they grow. When it comes time to molt, they will fasten their bag to their preferred food plant and push the old exoskeleton out through the top. When ready to pupate, they attach their case to a twig or other object one last time. Males emerge winged and fly to waiting females, who are wingless or have wings reduced to tiny stubs. After mating, the female lays her yellowish eggs on or in the case and dies — or may even die with the eggs still inside her. Some species are parthenogenetic and skip the mating step altogether.
Klara Briknarova, August 3rd, 2024. Missoula, MT.
Norton’s Giant Ichneumon Wasp
Megarhyssa nortoni
This wasp’s ovipositor, the structure at the tip of the abdomen used for laying eggs, is impressive—about two times its body length. How she wields it is pretty extraordinary; after locating horntail larvae, a type of wasp larvae that bores in wood, she positions herself with back legs extended and ovipositor perpendicular to the bark and drills into the tree to deposit an egg on or near a horntail larva within its burrow. When the egg hatches, it becomes an external parasite that ultimately consumes the larva. It pupates within the burrow and emerges in the summer. The western giant ichneumon can be found in forested regions from Newfoundland south to northern Georgia, west to Alaska & California (also introduced in Australia and New Zealand).
Monica Haaland, August 14, 2024. Eureka, MT.
Anise Swallowtail
Papilio zelicaon
Anise Swallowtails are widespread and numerous in the west and are so-named for the caterpillars’ penchant for feeding on plants in the parsley family, including the introduced sweet fennel, or anise. These are some of the first swallowtails we see in the spring, flying from late April to July among bare hills, mountains, gardens, fields, vacant lots, and roadsides.
Carolyn Taber, August 9th, 2024. Glacier National Park, MT.
Bent-winged Owlet
Bleptina caradrinalis
This moth is another excellent example of using the reniform spot as a key identifying feature. In males, the distinctive marking is more prominent, but as this species is widespread, individuals vary from region to region. This species is found across North America, from southern Canada as far south as Brazil. While they are found in nearly every state, they are more common in the East. They commonly inhabit wooded and shrubby areas near water, and their larvae will feed on leaf litter as well as live plants like hickory, clover, and barberry.
Judy Halm, August 7th, 2024. Spokane Creek, Helena, MT.
