Monthly Archives: September 2014

Virginia ctenucha (Ctenucha virginica)

Virginia ctenucha

Photo by Bill Reynolds

Virginia ctenucha (Ctenucha virginica),  a common and widespread, colorful, medium-sized moth, is the largest wasp moth in North America. It is found from mid-June to late July in moist, open, grassy fields and meadows. Although it is a day-flying moth it is also attracted to lights at night.

This and other Ctenuchid moths have three adaptations that help to protect them from predators: the metallic blue color of the body mimics wasps which may be noxious to predators; caterpillars retain toxic chemicals from the plants they eat; and a specialized region on the thorax produces ultrasonic sounds which jam the sonar of moth-eating bats.

This species is identified by the incomplete yellowish-orange collar and the broad wings with no markings.

Common green bottle fly (Lucilia sericata)

common green bottle fly

Photo by Bill Reynolds

There are many species of green bottle fly. Common green bottle fly (Lucilia sericata) is certainly the most well known and probably the most scientifically studied green bottle fly in the world. As its common name suggests, it is common and widespread, found in all of the temperate and tropical regions of the planet.

This is often one of the first insects to visit a corpse, sometimes within minutes of death. Forensic scientists use the development of the larva of this species to determine the age of a corpse. Medicinally, the larvae are used on humans to painlessly remove dead or decaying tissue from wounds while leaving healthy tissue untouched and secreting a chemical that promotes tissue regeneration.

This species is identified by three grooves across the thorax and three bristles on the upper middle (dorsal) surface of the middle thoracic section.

Winter firefly (Ellychnia corrusca)

winter firefly

Photo by Bill Reynolds

Winter firefly (Ellychnia corrusca) is the most common diurnal firefly, also called lightning bug, in Minnesota. It is medium-sized for a firefly but much larger than other species within its genus. Unlike most fireflies it has no bioluminescent organs and is active during the day. The common name reflects the fact that it overwinters as an adult. On warm, sunny, winter days an individual might be seen on a tree trunk wandering a short distance from its wintering spot.

This species is identified by the size, minute hairs on the forewings, and distinctive “parentheses” marking on the thoracic shield.

Isabella tiger moth (Pyrrharctia isabella)

Isabella tiger moth

Photo by Bill Reynolds

In its larval (caterpillar) stage, Isabella tiger moth (Pyrrharctia Isabella) may be the most widely recognized moth in North America. Most of us have seen a woolly bear crossing a sidewalk, driveway, road, or parking lot. It has a densely bristly body that is black on both ends and orange in the middle. The adult is less conspicuous but equally distinctive. They are nocturnal and therefore rarely seen.

Folklore says that the size of the orange band predicts the severity of the coming winter, with wider bands forecasting a milder winter. This means of forecasting is probably as accurate as the Farmer’s Almanac, though not as accurate as the National Weather Service.

American bittersweet (Celastrus scandens)

American bittersweet

Photo by Kirk Nelson

American bittersweet (Celastrus scandens) is a widespread and, in Minnesota, fairly common woody vine. Unlike most vines it does not produce tendrils or aerial roots. It climbs by growing spirally from left to right up a tree or other adjacent vegetation. In the fall the bright orange fruit coverings splits open into three parts and folds back to reveal 3 to 6 bright red, berry-like seed coatings. The fruits remain on the vine through the winter, adding interest to the colorless landscape. They are poisonous to humans but not to birds.

American bittersweet is similar in appearance to the exotic invasive Oriental bittersweet. The best way to identify them is by leaf shape, location and number of flowers, and fruit color. American Bittersweet has leaves that are often twice as long as wide; clusters of 5 to 60 flowers at the ends of branches; and orange fruit capsules. Oriental bittersweet has broader, sometimes almost round leaves; clusters of 2 to 7 flowers in leaf axils; and yellow fruit capsules.

Clifton E. French Regional Park

Clifton E. French Regional Park

This popular urban park on the north shore of Medicine Lake is surrounded on three sides by suburban housing. It has everything that its many visitors want, including a picnic area, fishing dock, swimming beach, boat launch, and a large playground. It also has 5.2 miles of natural surface hiking trails through deciduous woodlands. Visitors who come here for the trails are advised to come on a weekday when it is less crowded but still well used.

White snakeroot (Ageratina altissima var. altissima)

white snakeroot

Photo by Kirk Nelson

White snakeroot (Ageratina altissima var. altissima) is a late bloomer, one of the last flowers to be seen in the fall in the woods of Minnesota. At that time of year it is certainly the most conspicuous. The inflorescence is a flat-topped to dome-shaped, up to 3″ in diameter cluster of many white flower heads at the end of the stem. On larger plants they also appear on long stalks from the upper leaf axils.

This plant is poisonous to livestock. It was unusually abundant in southern Minnesota in 2004. A number of horses in the New Ulm area died in the summer of that year, and it is thought that white snakeroot is the cause. If eaten by cows the cow’s milk may also cause “milk sickness” in humans. Nancy Hanks Lincoln, the mother of Abraham Lincoln, is thought to have died of milk sickness in 1818.

Blue Ridge carrionflower (Smilax lasioneura)

Blue Ridge carrionflower

Photo by Bill Reynolds

There are seven species of carrionflower (Smilax) found in Minnesota. Blue Ridge carrionflower (Smilax lasioneura) is by far the most common and widespread. It is found throughout the state in woodlands, woodland borders and openings, thickets, fencerows, roadsides, and other open areas. The seven species are differentiated by the stem, the tendrils, the length of the leaf stalk, the hairiness of the leaf, and the length of the flower cluster stalk. Blue Ridge carrionflower has a non-woody, easily crushed stem with no thorns or bristles; long, conspicuously curled tendrils in almost every leaf axil; a leaf stalk that is shorter than the leaf blade; hairs on the veins of the lower leaf surface; and a flower cluster stalk that is 1 to 5 times as long as the stalk of the subtending leaf.

Glacial Lakes State Park

Glacial Lakes State Park

Several state parks in western Minnesota preserve parts of the state’s once vast tallgrass prairie. The best of these by far is Glacial Lakes State Park. It is located in the Leaf Hills, a 10 to 19 mile wide region of glacial hills stretching from Detroit Lakes to Willmar. Hiking trails on treeless, wide open prairie lead over rolling hills, eskers, kettles, and moraines. One section of the prairie loop trail follows ridge line with spectacular views of the prairie below. Another trail leads through bur oak forest. In all, there are 16 miles of natural surface hiking trails. If you visit, come early and plan to spend the whole day.

Purple-stem beggarticks (Bidens connata)

purple-stem beggarticks

Photo by Bill Reynolds

Purple-stem beggarticks (Bidens connata) is one of the nine species of Bidens found in Minnesota. These plants are differentiated by the division of leaves, the number of outer bracts below the flower head, the size of the flower head, the presence or absence of ray florets, the color of disk florets, and the number of awns on the seed capsule. Purple-stem beggarticks is often most easily identified by the color of the stem. The stem may be green tinged with purple or mostly or completely purple. The leaves often turn purple or purplish in the fall.