Monthly Archives: July 2018

Iowa skipper (Atrytone arogos iowa)

Iowa skipper

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.

Wild indigo duskywing (Erynnis baptisiae)

wild indigo duskywing

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.

Hygroscopic Earthstar (Astraeus hygrometricus)

Hygroscopic Earthstar

Photo by Luciearl

Hygroscopic Earthstar (Astraeus hygrometricus) is a late season, small or medium-sized mushroom—small when closed, medium-sized when open. The fruiting body looks like a puffball at first. As it matures the outer layer of the case splits into 6 to 15 pointed rays, exposing a nearly spherical spore sac. When fully expanded, it can be 3″ or more in diameter. When moist, the rays arch backward to the ground, raising the spore sac, and facilitating distribution of the dust-like spores. The rays sometimes have a pale foreground with dark cracks and crevices, appearing like dried, cracked mud in a dry lake bed. In dry conditions they fold back over the spore sac and become hard. At maturity, the spore case ruptures through a pore at the top, and the spores are disbursed by the wind.

Hygroscopic Earthstar has a global distribution. It is common in North America, Central America, and Europe, and has been collected in Africa, Asia, and Australia. In the United States it is common in the Great Lakes and coastal states, uncommon in Minnesota.

Hygroscopic Earthstar is similar in appearance to true earthstars but it is not even closely related. It is an example of convergent evolution, where species of different lineages evolve similar features. It is identified by the following characteristics: the rays are hygroscopic, expanding in moist conditions and covering the spore case in dry conditions; the upper ray surface is often pale with dark cracks and crevices; the lower ray surface is covered with matted, blackish, hair-like fibers; the spore case is stalkless, roughened by numerous particles, and ruptures through a single, poorly defined pore at the top; and the spores are very large, but this can only be seen under a microscope.

Cocklebur weevil (Rhodobaenus quinquepunctatus)

cocklebur weevil

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.

Pandorus sphinx (Eumorpha pandorus)

pandorus sphinx

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.

Purple-bloom Russula (Russula mariae)

Purple-bloom Russula

Photo by Kirk Nelson

Purple-bloom Russula (Russula mariae) is a medium-sized gill mushroom. It is common and widespread in deciduous and mixed woodlands and forests of North America east of the Rocky Mountains. It is found from June through October, singly or in groups, on the ground near hardwoods. It obtains its nutrients from the rootlets of oak and other hardwood trees.

Purple-bloom Russula is easily recognized by the flat, dry, velvety or powdery, purple cap.

Pin cherry (Prunus pensylvanica)

pin cherry

Photo by Luciearl

Pin cherry (Prunus pensylvanica) is a small, fast-growing, short-lived, deciduous tree. It is common from New England to the upper Midwest and across southern Canada, uncommon and scattered west of the Great Plains. It is common throughout Minnesota except for the southwest quarter.

Pin cherry reproduces mostly by root sprouts and often forms thickets. In forests, it rarely germinates, and when it does, the saplings rarely survive except in large openings with plentiful moisture and light. Seedlings mostly appear in a forest after heavy cutting, burning, or a blow down. They mature rapidly and live only 20 to 40 years.

Pin cherry can easily be mistaken for black cherry or American Plum. Unlike black cherry, the bark remains thin and smooth on mature trees; the leaves are yellowish-green, not dark green; the leaf tips are drawn out into a long thin point; and the inflorescence is an umbrella-shaped cluster of 2 to 7 flowers, not a 3″ to 6″ long cluster of 20 to 60 flowers. Unlike American plum, the branches do not have spines, and the inflorescence often has clusters of 5, 6, or 7 flowers.

Rhubarb curculio (Lixus concavus)

rhubarb curculio

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.

Mica Cap (Coprinellus micaceus)

Mica Cap

Mica Cap (Coprinellus micaceus) is a very common mushroom in Europe, Asia, Africa, and North and South America. In the United States is seen from coast to coast. It occurs from April through October in forests and woodlands, in suburbs, in urban areas, and sometimes indoors. It grows in dense clusters on decaying stumps and logs, and sometimes on the ground on buried wood.

When young, it is dome-shaped, yellowish-brown, and covered with glistening particles. As it matures it flattens out, the particles wash away, and the cap becomes gray at the margins. As the mushroom ages the cap turns black, the margins become tattered, and the gills dissolve into an inky black liquid that drops to the ground.

Red raspberry slime mold (Tubifera ferruginosa)

red raspberry slime mold

Photo by Kirk Nelson

Slime mold is a term of convenience grouping together several kinds of unrelated organisms. They were formerly placed in the Fungi kingdom because they produce structures containing spores (sporangia). The modern classification has them divided among several supergroups. The taxonomy of slime molds changes frequently—it is a work in progress.

Red raspberry slime mold (Tubifera ferruginosa) is one of the most commonly encountered slime molds in woodlands. It appears from June through November as a pink to bright red, pillow-shaped, tightly-packed mass on well-rotted logs, sometimes on moss. The surface is knobby, like a raspberry. It is not edible.