Dusky slug (Arion subfuscus/fuscus) is common, exotic, terrestrial slug. It is native to northern Europe and was introduced into North America in the vicinity of Boston in 1842. By 1940 it was widespread across North America. It is found in moist or wet areas in deciduous and coniferous woodlands, in meadows on rocks, and in old fields and waste places. It is often encountered in areas of human activity, including in roadsides, gardens, campgrounds, wood piles, and window wells. In natural areas it is sometimes more abundant than native snail and slug species. It can a pest of agricultural crops, forest replantings, and gardens.
Two species of dusky slug are often treated as a single species complex, a group of species so similar that the boundaries are unclear. Aside from their geographic distribution, the two species can only be distinguished by the size and color of the genitalia of dissected individuals, or by analysis of their alloenzymes. Both species have been introduced into North America.
Adults are long and slender when extended, short and bell-shaped when contracted. The body is covered with rows of pale bumps, giving it a finely granular appearance. It is variable in color, but populations generally fit into one of four color groups: blackish-brown, yellowish-brown, orange, and reddish-brown. The orange or yellowish-orange color is mostly – or completely – due to a covering of mucus. When handled, the mucus will stain the handler’s fingers. There is usually a brown stripe on each side.
Great pond snail (Lymnaea stagnalis) is a very large, air-breathing, freshwater snail. It is commonly sold as an aquarium pet. The body contains both male and female reproductive organs (hermaphroditic). During copulation either the male role or the female role can be performed, though not both. This makes it the ideal subject for recent scientific research into handedness (chirality).
Great pond snail occurs in Europe, Asia, North America, and southern Australia. It occurs throughout the United States and Canada, but it is uncommon south of the 40th parallel. It is common in Minnesota. It is found in permanent, slow or still waters, usually with dense vegetation, including creeks, streams, rivers, marshes, swamps, and reservoirs, and at the edges of lakes and large ponds.
The shell is thin and has 4½ to 6 whorls. The last whorl is the body whorl and is greatly inflated. The remaining whorls are elevated forming a sharply pointed spire. When seen with the tip at the top and the opening facing up, the opening is on the right side. There is no door-like structure covering the opening of the shell. The shell is variable in color, tan to dark brown, and it has no obvious markings. A cavity within the shell has an air bubble that is refreshed every time the snail rises to the water surface to breathe.
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.
Ruby Bolete (Hortiboletus rubellus) is a small, red capped, blue staining mushroom. It occurs in Europe, the United States, southern Canada, and Mexico. It reaches the western extent of one part of its range in eastern Minnesota. It is found in summer and fall in woodlands, parks, and gardens. It grows on the ground near oaks and other hardwood trees.
The cap is small, no more than 2⅜″ in diameter, and is bright but dark pinkish-red. This is the feature that gives the mushroom its common name. It often has a thin yellow or whitish band around the margin. The pore surface on the underside of the cap is yellow. It quickly stains dark blue when bruised. The stalk is up to 2¾″ long, is mostly red, and has many tiny red dots. When cut lengthwise, the flesh of the stem reveals numerous, tiny, bright red or carrot orange dots near the base.
Ruby Bolete is edible but it has a soapy taste, and like other boletes, it is often infested with maggots.
There are between 100 and 250 species of sap staining fungi, and they are divided into three groups. One of these groups is known as blue stain fungi. It is an informal grouping of various species of sac fungi (Ascomycota) that cause blue discoloration in the heartwood of trees without destroying the wood. The fungi are from the genera Ceratocystis, Ophiostoma, Ceratocystiopsis, and Grosmannia. They do not form a single taxonomic group because they do not descend from a common ancestor. Not all species in those genera cause blue staining.
Blue stain fungi spores are carried to a living tree on the body of a wood boring beetle. Their thread-like cells (hyphae) produce dark melanin on their walls to protect them from light, drought, and the tree’s own defenses. Blue discoloration spreads from the wound on the outside through the heartwood in a wedge-shaped pattern following the spread of the fungus. Boxelder trees produce a brilliant red stain in the wood as a response to the fungus.
Blue stain fungi damages the living tree by clogging the vascular system, leading to decline and premature death of the tree. The damage caused to the wood is merely aesthetic. The discoloration makes the wood undesirable and less profitable but does not weaken the wood.
Araneidae is a large family of typical spiders known as orbweavers. It is the third largest family of spiders. There are 3,067 currently recognized orbweaver species in 177 genera worldwide, 180 species in North America north of Mexico, and at least 44 species in 16 genera in Minnesota.
Orbweavers are found in woodlands, fields, and caves; on grasses, shrubs, and trees; and on buildings and fences. They are best known for the circular webs, called orbs, that they build. The webs consist of a framework of non-sticky threads (spokes) extending from the edge to the middle, and concentric circles of sticky threads winding to the center.
Orbweavers are very diverse in size, shape, and color. They have eight small eyes in two rows. The lateral eyes are usually well separated from the median eyes. The median ocular area (MOA), the area defined by the middle four eyes, is in the shape of a trapezoid. The front part of the body (carapace) is smaller than the rear part (abdomen). The abdomen is large, rounded, and marked with lines, spots, or zig-zag patterns. The legs are short and spiny. The first and second pairs of legs project forward, the third and fourth pairs project backward. There are three claws at the end of each leg, though these are not visible without magnification. Females are much larger than males.
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.
Grimmia dry rock moss (Grimmia laevigata) is a common and widespread tuft-forming moss. It occurs on all continents except Antarctica. It is mostly restricted to the moderate climate areas of the northern and southern hemispheres. It is less common in Minnesota where it reaches the northern extent of its range. In this state it is found in open areas on rock outcrops. It grows under full sun on exposed acidic rock or on thin soil over rock.
Grimmia dry rock moss is extraordinarily drought resistant. Dried herbarium specimens that have been rehydrated after ten years have resumed photosynthetic and metabolic activity. It has adapted to a broad range of environments, yet it shows very little variability throughout its range. Bryologists suggest that a single species cannot be so adaptive, and that Grimmia laevigata must consist of a group of apparently indistinguishable but genetically distinct species.
Grimmia dry rock moss appears as a dense, hoary, dark green to dark brown tuft. The leaves have a long, thin, translucent, hair-like awn at the tip that constitutes almost half the total length of the blade. Spore-producing reproductive structures are rarely produced, and apparently are not produced anywhere in our area.
Brickwork woodlouse (Porcellio spinicornis) is a large, exotic woodlouse. It is native to Europe, where it is widespread and common. It was introduced into North America, where it now occurs across southern Canada and in the United States from Maine to New Jersey, west to North Dakota and South Dakota. It is not uncommon in Minnesota.
Brickwork woodlouse favors dry areas with limey (calcareous) surfaces. It is found in limestone quarries, on limestone pavement, in loosely mortared walls, and often in human houses. It is active at night, when it can be found on the surface. During the day it remains concealed, often under a rock or log.
Brickwork woodlouse is yellowish with dark brown to almost black mottling, and a dark brown to almost black stripe in the middle bordered on each side by bright yellow markings. One imaginative describer likened the pattern to brickwork, and this is the source of this species’ common name.
Apple Blossom Overlook Park is a Winona County park located three miles north of downtown La Crescent, MN on Apple Blossom Drive Scenic Byway. Its 55 acres includes a ridge top overlooking the Upper Mississippi River Valley 580 feet below. A 1.3 mile loop trail has a spur that leads to a spectacular overlook on a narrow promontory. The trail is wide, grassy, and well maintained. It passes through new and old growth hardwood forest, two newly established prairies, and a few small areas of remnant prairie, and by rock outcroppings, steep cliffs, and an historic stone quarry. The park also includes a small depression that is sometimes a small pond but at other times just a wetland.