Could we ask for better buggin’ weather? This past week has shown quite the turnout. Bugs are so abundant right now that you don’t have to look for them; as Joey and June discovered while on a river float with their dad, the bugs will come to you! Do you think the giant stonefly that landed on their boat was searching for a mate amongst their flies?
Header Photo: Giant Stonefly (Pteronarcys sp.) Joey and June Gonzalez, June 1st, 2024. Smith River, MT.
Knapweed Root Weevil
Cyphocleonus achates
This non-native weevil was introduced in the 1980s to help combat another exotic — spotted knapweed. Females lay their eggs on the top of the knapweed’s root crown. Once they hatch, the larvae burrow into the plant’s root, destroying the vascular root tissue and preventing it from transporting water and nutrients. Death of the plant can occur within two years. Research at Montana State University has shown a 99% reduction in knapweed density due to the introduction of knapweed root weevil. Go weevils!
Carolyn Taber, June 11th, 2024. Waterworks Hill, Missoula, MT.
Common Ringlet
Coenonympha California
The eyespot on the underside of the forewing can often help identify this relatively small butterfly, but as with many insects (butterflies especially), they vary greatly. The color of their wings can range from dark orange-brown to pale cream. They have a relatively slow, bouncing flight and tend to be found in grassy, open areas. Once considered Coenonympha tullia, genetic testing has separated these butterflies into distinct species, with C. tullia only found in northern Europe.
Misty Nelson, June 8th, 2024. Erskine Fishing Access Site, Frenchtown, MT.
Oblique-lined Tiger Beetle
Cicindela tranquebarica
These insects are FAST. Tiger beetles have been clocked running at 1.38 feet per second (about 29 body lengths). That may not sound like a lot, but factoring in their size, it’s similar to a grizzly bear running over 135 miles per hour. They run so fast that they outrun the capacity of their eyes and brain to process what they see fast enough, so they run themselves blind and need to stop, look around, and then continue their pursuit of their prey. This species is found across North America (except for the Gulf and Pacific coastlines and areas of the Cascades and BC Coast Range), typically in open habitats. Riverbanks are favored haunts.
Kristi DuBois, June 7th, 2024. Mineral County, MT.
Red Flat Bark Beetle
Cucujus clavipes
Do you ever look at a bug and immediately picture a cherry Dilly bar? No? Just me? As their common name implies, Red Flat Bark Beetles are exceptionally flat, allowing them to live in the narrow spaces between the bark and wood of dead trees, logs, and stumps. The adults and the larvae prey on other beetles that develop in wood. Other small arthropods, fungi, and plants are also on the menu. This species is often found under tree bark, especially pines and poplars.
Henry Hirschenberger, June 10th, 2024. Greenough Park, Missoula, MT.
Mosaic Darner
Aeshna sp.
Last week, we featured a group of dragonflies emerging from their nymphal exoskeletons; this week features another recently-emerged adult, but this one may have already taken its first flight. Its color hasn’t fully developed, but it is a striking dragonfly nonetheless. They tend to inhabit lakes and ponds with dense shoreline vegetation, marshy areas, fens, and slow-moving streams and sloughs. Darners are swift and agile hunters, catching various flying insects in midair — mosquitos, moths, flies, flying ants, and even smaller dragonflies.
Jennifer Wells, June 8th, 2024. Missoula, MT.
Six-spotted Orbweaver
Araniella displicata
The six-spotted orbweaver may be the original itsy bitsy spider. The largest females rarely measure over 7mm long, with their legspan maxing out at 17mm. Like the majority of spider species, the males are even smaller. Unlike many female orb weavers, who are mature and gravid in the fall, A. displicata lays her eggs in early summer. Many orbweaver species die off, leaving their eggs to overwinter in their egg cases, but by fall, the six spotted orbweaver eggs have already hatched. The spiderlings overwinter in their juvenile stage, seeking a warm retreat to shelter themselves from the harsh winter conditions.
Sal Culotta, June 6th, 2024. St. Ignatius, MT.
Stream Mayfly
Family Heptageniidae
When mayflies first emerge from the water, they are commonly called a dun (scientifically called the subimago stage). As duns, mayflies physically resemble the final adult stage but are sexually immature and duller in color (the eyes, legs, and genitalia are not fully developed). Depending on the species, within a few minutes to a few days, the dun will molt a final time into the sexually mature adult (or imago). The mature adults lead ephemeral lives, normally living only a day or two, and with only vestigial mouthparts, they do not eat.
Lisa Cloo, June 6th, 2024. Turah, MT.
Red Net-winged Beetle
Dictyoptera simplicipes
Red net-winged beetles can be challenging to distinguish, but the red legs and light black diamond shape on this beetle’s pronotum give it away as D. simplicipes (Latin for “simple-legged”). The bright red color suggests a distasteful (or poisonous) meal to potential predators. These beetles call coniferous and mixed forests across northern Eurasia and North America home. Larvae feed on decaying wood, while adults enjoy nectar, pollen, and small insects.
Misty Nelson, June 8th, 2024. Bass Creek, Florence, MT.
Western Sculpted Pine Borer
Chalcophora angulicollis
The only western species in the genus Chalcophora, the western sculpted pine borer is so named for the “sculpted” look of the elytra and thorax. As a member of the metallic wood-boring beetle family, it doesn’t come across as “metallic” at first. However, once she lifts her elytra (wing covers) for takeoff, she reveals her abdomen’s striking blue and purple iridescence. If one is flying nearby, you’ll likely hear it before you see it. These enormous beetles are conspicuously (and sometimes alarmingly) loud aviators.
Shelley Longgood, June 9th, 2024. Evaro Hill, MT.
Coreopsis Beetle
Calligrapha californica
Misty found this striking leaf beetle in her mini-meadow, “anxiously waiting for the Coreopsis (Tickseed) to bloom.” Reports on this beetle’s distribution are scattered, with little information on their preferred habitat in Montana, but hanging around Coreopsis is a good place to start. Their larvae are comically described as “[black-headed, with] a dark brown rotund body twice as wide as the head and three times as long.”
Misty Nelson, June 8th, 2024. South Hills, Missoula, MT.
