Photo by Scott Leddy
Iowa skipper (Atrytone arogos iowa) is a species of special concern in Minnesota. Its populations are restricted to undisturbed tallgrass and shortgrass prairies in the Great Plains. Massive habitat destruction and excessively frequent prescribed burning on managed prairies are major threats to the subspecies survival. It is declining in the northern parts of its range. It is no longer found in 200 western counties it was once known from. It is estimated that there are over 100 remaining populations, but those are small and scattered. It is considered uncommon to rare wherever it occurs. In Minnesota, it is found mostly in the southwest quarter of the state.
Iowa skipper is a small to medium-sized grass skipper. The wings are yellowish-orange with a broad, dark border. The female has a thin black streak in the center of the forewing, but otherwise the wings are unmarked. When at rest, the forewings are held at a 45° angle and the hindwiings are held horizontal, a configuration that resembles an F-15 Eagle fighter jet.
Iowa skipper is similar in appearance to the Delaware skipper (Anatrytone logan), which is much more common. Iowa skipper is distinguished by the lack of any black veining on the upperside of the wings; lack of a black cell end bar on the forewing; wing undersides not as bright; and the hindwing fringe that is usually white, not tan or orange.
Photo by John Shier
Wild indigo duskywing (Erynnis baptisiae) is a medium-sized spread-wing skipper. It is widespread, abundant, and increasing in the east and the Midwest, but rare in Minnesota.
Wild indigo duskywing was originally a species of open woodlands and shrubby prairies. The larvae fed on mostly on horseflyweed but also blue wild indigo and sundial lupine. With the decline of those species due to habitat loss, the skipper adapted to the introduced, locally abundant species crown vetch. Today, its range is rapidly expanding and its numbers are increasing wherever crown vetch has been widely planted.
Wild indigo duskywing has dark brown wings; a pale spot at the end of the forewing cell; and four translucent white spots at the leading edge near the tip of the forewing. Along with columbine duskywing and Perseus duskywing, it is part of the “Persius species complex”. They are very similar in appearance and difficult or impossible to distinguish in the field. Columbine duskywing is smaller, lighter, and has shorter wings. Perseus duskywing has not been recorded in Minnesota.
Photo by Alfredo Colon
Cocklebur weevil (Rhodobaenus quinquepunctatus) is a medium-sized snout beetle. It is widespread in the eastern half of the United States. Adults eat the stalks and leaves of cocklebur, ragweed, thistle, ironweed, Joe Pye weed, sunflower, marsh elder, and rosinweed. Larvae bore into the stems and roots of the same species. It is easily controlled and does not occur in numbers high enough to become an agricultural pest.
Snout beetles are identified by their very long snout. Cocklebur weevil is identified by the reddish-orange body; the oval-shaped black spot in the middle of the thorax; and ten black spots on the wing covers that usually merge to some extent with neighboring spots, especially toward the rear.
Photo by Chad & Autumn Brekke
Pandorus sphinx (Eumorpha pandorus) is a very large, dramatically patterned, sphinx moth. It is common and widespread in eastern United States. Adults fly at dusk from May to September. They have a wingspan of 3¼″ to 4½″, and a pale green background with a complex pattern of dark olive-green markings.
Humans are more likely to encounter caterpillars than adults. Known as hornworms, the caterpillars are found on grape and Virginia creeper in Minnesota, and also on peppervine elsewhere. They are very large, up to 3½″ long, and consume copious amounts of foliage. They can completely defoliate young grape vines, ultimately killing them. Older vines can withstand the damage.
Pandorus sphinx is similar in appearance to Achemon sphinx (Eumorpha achemon). The latter species is smaller and less common, and the adults are brown, not green.
Photo by Alfredo Colon
Rhubarb curculio (Lixus concavus) is a large, easily identified, true weevil. It is common from New Hampshire, south to North Carolina, and west to Utah. It is uncommon in the upper Midwest, including Minnesota. At up to ⅝″ in length and 3 ⁄16″ in width, it is one of the largest snout beetles in the United States.
Rhubarb curculio adults are active from mid-May to September. They are found on stalks and leaves of thistles, sunflowers, docks, and rhubarb. They are one of only two weevil species that attack rhubarb. They can be a pest to crops of these plants but they are easily controlled.
Snout beetles are easily identified by their long, flattened or cylindrical snout that is at least as long as the pronotum. Rhubarb curculio is easily identified by the bright yellowish bloom on the head, pronotum, and wing covers.
Photo by Alfredo Colon
Long-tailed dance fly (Rhamphomyia longicauda) is a small, black, long-legged fly. It is commonly found from May to July in deciduous woods near water. The wings are long and black. The head is round with large bright orange or red eyes. On the female, the middle and hind legs have a fringe of long, black, bristly hairs.
Every evening around sunset, males and females collect in same-sex swarms. Females and fly up and down, the behavior that gives this family its common name “dance-flies”. Females cannot hunt for prey. They receive protein from males as gifts in exchange for copulation. They swallow air, filling and extending their abdomen outward, saucer-like, falsely signaling males that their eggs are nearing maturity. The long hairy legs wrap around the abdomen, making it appear even larger. Males are attracted to females that have largest swollen abdomens and hairiest legs. An individual will break off and join the other swarm to select a mate.
Photo by Alfredo Colon
Colorado potato beetle (Leptinotarsa decemlineata) is relatively small for a beetle but relatively large for a leaf beetle. Adults are ¼″ to 7 ⁄16″ long and about ⅛″ wide. The body is oval when viewed from above and dome-shaped when viewed from the side. The wing covers are pale yellow with five black lines on each side. The are no similar species in Minnesota.
Prior to European settlement, the Colorado potato beetle was found only in Colorado and neighboring states. The potato was introduced into North America in the 1600s and began to be widely grown in the early 1700s. By 1840 the potato reached the insects home range. By 1859 the insect had switched to the potato as its preferred host, and by 1874 it had spread all the way to the east coast. It is now present across North America, Europe, and Asia.
Colorado potato beetle is a serious crop pest to potato growers. The insect rapidly evolves resistance to chemical pesticides. Many insecticides that once successfully controlled the beetle are no longer effective.
Photo by Alfredo Colon
Four-lined plant bug (Poecilocapsus lineatus) is a small, soft-bodied, colorful, true bug. It is common in northeastern and midwestern North America, including Minnesota. It is easily identified by the bright yellow or green body with four black stripes and the orange head. It can be seen from May to July in meadows, gardens, agricultural fields, and around homes.
Four-lined plant bug is considered a pest due to the damage it causes to ornamental plants. Adults and larvae feed on the leaves of herbaceous plants, especially those in the mint and aster families. Leaf damage appears as small, 1 ⁄16″ or less in diameter, light or dark spots on the leaf surface. The color of the spot varies with the species of the host plant. The spots are collapsed leaf tissue which eventually falls out leaving small holes. Larvae cause more leaf damage than adults.
Photo by Dan W. Andree
Six-spotted tiger beetle (Cicindela sexguttata) is a small predaceous, tiger beetle. It is probably the most common species of tiger beetle in eastern North America, possibly the most common on the continent. It is found in the southern two-thirds of Minnesota. Adults and larval burrows are very often seen on paths in the woods. Six-spotted tiger beetle can be thought of as a woodland path species.
The head and body are shiny, iridescent, and usually metallic green, occasionally blue. Flashy tiger beetles (subtribe Cicindelini) are usually identified by the color and pattern of marks on their wing coverings. The common name of this species comes from white spots on the wing covers. There are usually six small spots, often eight, rarely ten, and occasionally none.
Checkered white (Pontia protodice) is a medium-sized butterfly with a wingspan of 1½″ to 2½″. It is a southerly species and is uncommon in Minnesota. There are two overlapping broods here, early June to August (spring form) and July to mid-October (summer form). The wings are white with dark markings, including a checkered pattern on the outer margin. The female has more extensive markings than the male, and the spring form has darker markings than the summer form. The larva (caterpillar), known as the southern cabbageworm.
Checkered white populations have drastically decreased in eastern Unites States, and the butterfly is now scarce or extirpated in some areas where it was once common. It appears stable in the west. The cause of the decline is unknown, though habitat loss is certainly a contributor. It is possible that the extremely abundant introduced species cabbage white is displacing native whites, including checkered white. It is also possible that checkered white is a western and midwestern species that only sporadically became abundant in eastern agricultural fields. It remains to be seen whether the decline will continue to spread westward.