Horned spanworm moth (Nematocampa resistaria) is a small geometer moth. It occurs across the United States and southern Canada. In the U.S. it is common east of the Great Plains and in the northwest but is rare or absent elsewhere. Adults are found from early June to late September in deciduous and mixed forests and woodlands, in meadows, and in parks.
Female forewings are whitish or cream-colored with reddish-brown lines and veins, numerous short horizontal lines, and a purplish-brown patch on the inner half of the wingtip. The hindwing is similar, but the entire tip of the wing is dark. The male is similar but smaller, is usually yellowish, and there is a dark brown blotch at the tip of the wing.
The adult sometimes rests on the upper side of a leaf, where it resembles a dead leaf; on the underside of a leaf, where it resembles a dead patch; or on leaf litter on the ground, where it blends in with the background.
The caterpillar is up to ¾″ long and is instantly recognizable. The ground color varies from yellow to brown and is heavily mottled with brown. On each of the first and second abdominal segments there is a pair of curled, extendable, white-tipped tentacles (filaments).
The caterpillar often rests on an upper leaf surface with the body looped. It has been suggested that this mimics a fallen flower and its stamens. When alarmed, it inflates the filaments to twice their length.
Meal moth (Pyralis farinalis) is a small, broad-winged, triangular moth. It is cosmopolitan, occurring around the world, but is most common in Europe and the United States. It is found anywhere grain is processed or stored, including warehouses, barns, and most home pantries. It is not the only moth common to home pantries, nor is it the most common. That distinction belongs to Indian meal moth. Other common pantry moths are Mediterranean flour moth, brown house moth, and white shouldered house moth.
Meal moth larva feed on cereals (plants in the grass family), grains (edible seeds of cereals), and vegetables, including potatoes. Adults do not feed and are short-lived. They mate as soon as possible after emerging, then die after nine or ten days. They rest with their wings spread wide, their abdomen raised at a right angle to the body, and their antennae folded back over the body.
There are only two species of praying mantis in Minnesota, Chinese mantis and European mantis. Neither is native to North America. The most common by far is Chinese mantis (Tenodera sinensis sinensis). It is native to Japan, China, North and South Korea, Thailand, and Micronesia. It was accidentally introduced in Philadelphia in 1896. It is now common in the United States and southern Canada east of the Great Plains, in California west of the Rocky Mountains, and in most of Asia. It is uncommon in the southern third of Minnesota, where it is at the northwestern extent of its range, and is absent from the remainder of the state. It is found in grasslands, meadows, agricultural fields, and woodlands, and at the sides of streams and rivers.
Chinese mantis are large predaceous insects. They eat anything they can catch, including insects, small amphibians and reptiles, and hummingbirds. They remain stationary with their legs raised up as they wait for prey. Though they have wings, females do not fly. Males can fly only short distances. Adults are active in summer until fall, when they are killed by the first frost.
Chinese mantis is distinguished from European mantis by its larger size, the pattern of stripes and shape of plates on the face, a bold green stripe along the edge of the forewing, and a yellow spot between the front legs.
Leafy spurge hawkmoth (Hyles euphorbiae) is a large exotic moth. It is native to Europe and western Asia. In the 1960s it was introduced into the United States to control leafy spurge, and separately into Canada to control leafy and cypress spurges. Hawkmoth populations are never large due to predation and disease, and they are susceptible to insecticides used to control grasshoppers. While the larvae can entirely defoliate a host plant, the damage to the host plant population is never significant.
Since its introduction, leafy spurge hawkmoth has spread widely and its range continues to expand. It now occurs in the northern United States and southern Canada east of the Rocky Mountains. It is found from late May through July in disturbed meadows and other grasslands with large populations of leafy spurge. Larvae feed on the foliage of leafy spurge and other members of the Euphorbiaceae (spurge) family. Adults feed on flower nectar. They hover like a hummingbird when visiting flowers.
Leafy spurge hawkmoth is identified by its large size; pale tan forewings with a slight pinkish tinge; a squarish, olive-brown spot in the basal area and another in the median area; an olive-brown post-medial band; and black peppering in the pale areas.
Giant mayfly (Hexagenia limbata) is a large “common burrower” mayfly. It is very widespread, occurring in the United States and southern Canada from the east coast to the Great Plains and on the west coast. It is mostly absent from the desert and mountain regions in the west. It is the most common mayfly in the Midwest, and is common in Minnesota.
Larvae are found in organic, silty or mucky bottoms of lakes, ponds, and rivers, usually about three meters below the water surface. They feed on organic material suspended in the water. Immature adults are found on trees and bushes on shores near the bodies of water from which they emerged. Adults are found flying in swarms over land near the water body. They do not feed and live from just a few hours to a few days. Emergences are synchronized and can produce swarms so large that they can bee seen by weather satellites. Snow plows are sometimes used to clear dead mayflies off of roads.
Giant mayfly is said to be the largest mayfly in the United States. It can be more than one inch in length, not including two hair-like “tails” that can be equally long. The body may be yellow, yellowish-brown, brown, or even white. Aside from its very large size, giant mayfly is identified by the wing veination, and by the four-segmented end part (tarsus) of the hind leg.
Leonard’s skipper (Hesperia leonardus) is a large, late season, branded skipper. It occurs in North America east of the Rocky Mountains. It is listed as a Special Concern species in Minnesota, where it is declining due to habitat loss, insecticide drift from nearby croplands, and prescribed burning of managed prairies and savannas.
Adults fly from early August to mid-September. They feed on nectar from many flowers, including wild bergamot, heal-all, round-headed bush clover, asters, goldenrods, spotted knapweed, prairie ironweed, blazing stars, thistles, Joe-pye weed, and sunflowers. Larva feed on grasses.
There are three subspecies of Leonard’s skipper, two of which occur in Minnesota. The western subspecies, Pawnee skipper (Hesperia leonardus pawnee), is found in prairies in the west. The eastern subspecies, Leonard’s skipper (Hesperia leonardus leonardus), is found in dry prairies, savannas, open woodlands, and woodland openings in the east. The ranges of the subspecies overlap in eastern Minnesota, western Iowa, and western Wisconsin. In these areas the subspecies interbreed, producing “blended” offspring that are closer in appearance to Leonard’s skipper. The Leonard’s skippers in eastern Minnesota are all or mostly “blended”.
Northern broken-dash, Dun skipper, and little glassywing are called “the three witches” because their dark wings make it difficult to tell “which one is which.”
Northern broken-dash (Wallengrenia egeremet) is a small, dark, nondescript, grass skipper. It occurs in the United States and southern Canada east of the Rocky Mountains. It is most common in the northeast from Maine to Michigan south to Massachusetts and Ohio. It is uncommon but sometimes locally abundant throughout its range, including in Minnesota. Adults are found from late June to mid-August in open places near wooded or shrubby areas, including fields, pastures, meadows, woodland edges, gardens, and roadsides. They drink nectar from white, pink, and purple flowers, including alfalfa, red clover, dogbane, New Jersey tea, milkweed, and blazing star. Larva feed on the leaves of panic grasses.
The upper side of both wings is dark brown with pale markings and a brownish fringe. On the male the leading edge of the forewing is pale. The group of specialized scent scales (stigma) on the male forewing is black and is interrupted in the middle, like a “broken dash”. This is the feature that gives the species its common name.
Roesel’s katydid (Metrioptera roeselii) is a small, short-winged, shield-backed katydid. It is native to Europe, where it is called Roesel’s bush-cricket. In 1953 it was reported at two locations in Quebec. These were the first North American records. It now occurs in southern Canada from Prince Edward Island to Manitoba, and in the northern United States from Maine to Minnesota south to Maryland and Iowa. Adults are found from late June through October in meadows and grassy fields, at the margins of pastures, and in ditches and roadsides. They require a moist area with tall grasses that is undisturbed by mowing or grazing.
Adults are ½″ to 1″ in length and usually dark brown, sometimes yellow, rarely green. The plate covering the first segment of the thorax is brown on top, black on the sides, and cream-colored around the margins of each side. There are three pale green or yellow spots on each side of the thorax. Most adults have short wings and cannot fly. In most years, only about 1% have long functional wings. In years with exceptionally hot summers there are more winged adults.
Pond olive (Cloeon dipterum) is a small minnow mayfly. It occurs throughout Europe, where it is native, and in Asia and North America, where it has been introduced. The earliest North American record is from Illinois in 1953. It is now widespread across the continent. In the United States it is currently mostly restricted to the northeast and to Washington state. It is rare in Minnesota. Nymphs are found mostly in ponds, but also in the shallow margins of lakes and in slow areas of rivers and streams. They feed on algae, small aquatic organisms, and organic debris. Adults are found on vegetation near ponds. They do not feed and seldom live more than 1 or 2 days.
Adults are reddish-brown and have 2 very long hair-like tails at the end of the abdomen. The compound eyes on the female are on the sides of the head. On the male the compound eyes have additional large, orange, turban-like parts that meet at the top of the head. These adaptations are said to allow the male to isolate in a swarm females that are not yet paired with another male. Some authors say that pond olives have no hindwings. Carl Linnaeus in 1761 described the hindwings as “hardly present.”
Canada darner (Aeshna canadensis) is a large mosaic darner. It occurs across the northern United States and southern Canada. It is the most common blue darner in Minnesota, where it occurs throughout the state except for the western prairie counties. It is a late-season dragonfly, not appearing until late June and flying to the end of September.
Adults are about 2¾″ long. The body is dark brown with blue, green, or yellow markings that darken in cool temperatures. Males always have mostly blue markings. Females have three color forms; blue, green, and yellow. Most females are green form. Blue form females are rare.
There are at least ten blue darner dragonfly species found in Minnesota and they are difficult to tell apart. Canada darner is most easily distinguished by the lateral stripes on the thorax. The front stripe is deeply notched, is narrowed toward the top, and has a narrow rearward extension (flag) at the top. The rear lateral stripe is not notched. Like all mosaic dragonflies, there is a black T-shaped spot on the upper part of the face just below where the eyes meet. This is best seen when viewed from above. There is no bold black horizontal stripe across the middle of the face.