Some gorgeous weather in recent days has insect activity on the rise. This week we’re seeing early butterflies, stoneflies, native bees, and plenty more. With more sunshine in the forecast, who knows what will show up next week!
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:California Tortoiseshell (Nymphalis californica). Jalalieh Morrow, April 10th, 2025. Blue Mountain, Missoula, MT.
Nevada Tiger Moth
Apantesis nevadensis
There is only one generation per year of these striking tiger moths, with the flashy adults taking wing in late summer. The larvae overwinter as early instars and begin emerging on warm sunny spring days. When they pupate, they wrap themselves in silken cocoons, sometimes adorned with gravel, dirt, twigs, and even their own bristly hairs.
Connie Geiger, April 7th, 2025. Scratchgravel Hills, Helena, MT.
Rough Stink Bug
Brochymena sp.
Does this stink bug look like a familiar house guest? They’re not looking to eat anything, just a warm place to hang out until spring. That said, stink bugs are generally not very welcome house guests for one obvious reason: they stink. As a defensive measure, stink bugs emit foul smells to ward off predators – or occasionally an unwitting human trying to remove it from their home. As true bugs, they have piercing and sucking mouthparts that they use to pierce and consume plant tissues, and many are considered pest species.
Klara Briknarova, April 9th, 2025. Missoula, MT.
Western Tiger Beetle
Cicindela oregona
The western tiger is slightly smaller than our other tiger beetles in Montana (only 11 – 13 mm). Their color can vary from brown, green, purple to black. They are active in May and June, with the next generation appearing in late summer and fall. This beetle seeks out sandy, muddy habitats along rivers and has a 2-year lifecycle with both adults and larvae overwintering. Like other tiger beetles, they run so fast that they outrun the capacity of their eyes and brain to process what they are seeing. They literally run themselves blind and need to stop, look around, and then continue their pursuit of their prey.
Glenn Marangelo, April 5th, 2025. Council Grove State Park, Missoula, MT.
Shortwing Stonefly
Claassenia sabulosa
These large stoneflies get their name from their shortened wings, a trait that may hinder dispersal but certainly doesn’t slow them down. Once the adult males emerge, they can be seen scrambling across rocks, looking for a female. If he finds one that hasn’t molted into her adult stage yet, he will guard and mate with her as soon as she does (sometimes doing so before her exoskeleton has hardened). Like most stoneflies, the aquatic nymphs require clean, cold-flowing streams to thrive and are commonly used as indicators of stream health.
Klara Briknarova, April 5th, 2025. Lee Metcalf Wildlife Refuge, Stevensville, MT.
Early Tachinid Fly
Epalpus signifer
Tachinid flies, a family of true flies with over 8,000 described species are parasites and parasitoids of other arthropods. Adult flies will lay their eggs on or in a preferred host; some species will lay their eggs on the host species’ food source. Like many parasitoid wasps, only the tachinid fly larvae feed of their hosts, while adults prefer flower nectar or “honeydew,” a sugary aphid secretion. E. signifer is a widespread species, found throughout North America.
Glenn Marangelo, April 5th, 2025. Lee Metcalf Wildlife Refuge, Stevensville, MT.