Photo by Christa Rittberg
With 7,003 species in 530 genera worldwide, robber flies are one of the largest and most abundant families of insects alive today. Bee-like robber flies, as the common name for the genus suggests, resemble bees. There are 240 species of bee-like robber flies, 62 species in North America north of Mexico. Few of the species have been given a common name. Laphria sacrator is one of several species famous for being a bumble bee mimic, so “bumble bee mimic robber fly” will stand in for the common name.
Bumble bee mimic robber fly (Laphria sacrator) is a short, robust, medium-sized, bee-like robber fly. It is fairly common in northeastern and north-central United States, including Minnesota. It has a stout thorax and a short abdomen, both partially covered with long yellow hairs making it resemble a bumble bee. It is one of the hairiest of the bee-like robber flies. Adults are ⅝″ to 1″ long.
Photo by Christa Rittberg
Two-spotted bumble bee (Bombus bimaculatus) is small, colonial bumble bee. It is common in eastern North America and in Minnesota. It emerges very early in the spring and is active until mid-summer.
Two-spotted bumble bee usually nests underground but sometimes in the cavity of a dead tree. Like other bumble bees, it will sting to protect itself or its nest. The stinger is not barbed and the bee can sting multiple times. It feeds on the pollen and nectar of flowers. It has a very long tongue that allows it to feed on nectar of plants with long corolla tubes.
Two-spotted bumble bee is identified by the thorax which is yellow except for a small, round, black spot in the middle; the first abdominal segment is entirely yellow, the second has a broad, yellow, W-shaped spot in the middle, and the remaining (on the female) are all black; and the hairs on the back of the head are yellow.
Photo by Kirk Nelson
Crown-tipped Coral (Artomyces pyxidatus) is very common and widespread eastern North America. It grows alone or in groups on dead, well rotted wood of hardwoods, especially aspen, willow, maple, and cottonwood. It can be found throughout Minnesota from spring through fall. It is edible but tough and stringy. It has a peppery taste when raw that goes away when cooked.
The fruiting body is a candelabra-like profusion of whitish, upright branches with a tiny, crown-like tip. The branches turn brownish as they age. Occasionally, the tips of the branches are brown.
Crown-tipped Coral looks superficially similar to many club and coral fungi. It is identified by its growing on wood; the whitish or yellowish color when young; and the crown-like depression at the branch tips with 3 to 6 points.
Photo by Christa Rittberg
Brown-belted bumble bee (Bombus griseocollis) is a small, very common, colonial, ground-nesting bumble bee. It is the second most common bumble bee in eastern North America, after only the common eastern bumble bee. It is less common in Minnesota and the other northernmost states.
Bumble bees are the first bees out in the spring and the last bees out in the fall. Brown-belted bumble bees emerge earlier in the spring than most other bumble bees. They nest in the ground in small colonies of 50 or fewer individuals.
Brown-belted bumble bee is identified by the thorax which is yellow except for a small, round, black spot in the middle; the first abdominal segment is entirely yellow; the second has a single yellow, narrowly U-shaped spot in the middle and a brown band that swoops around the yellow spot; and the remaining are all black.
Designated on August 22, 2016, River Warren Outcrops SNA is one of Minnesota’s two newest SNAs. Its 89 acres include a prairie restoration, densely wooded bedrock outcrop, and floodplain forest along the east bank of the Minnesota River. Plains prickly pear and Kentucky coffee tree, two species of special concern in Minnesota, are found here.
Future management plans include the removal of buckthorn and redcedar from about 85% of the site, and continued restoration of a former agricultural field to prairie. An unusual feature of this SNA is 1.6 miles of horse trails. These trails were on the site when the land was purchased by the DNR, and they will continue to be maintained by the seller.
On rare occasions we come across a wild space so fragile or beautiful that we hesitate to publish it. We want to keep it to ourselves, to protect it and prevent it from being spoiled. The hidden cove at Crystal Spring Scientific and Natural Area, Minnesota’s newest SNA, is that kind of place. Crystal Spring SNA is near Taylor’s Falls in northern Washington County. Its 38 woodland acres are mostly red oak forest with small areas of black ash swamp.
A forest road and then a well-worn hiking trail lead from the northwest corner to the southeast corner of the SNA. The hiking trail eventually passes a set of winding steps that leads down a bluff and out of sight. The steps end at a sandstone cliff about 25 feet above a stream. A narrow trail at the base of the cliff but only halfway down the steep bluff leads to a hidden cove. The north wall of the cove is dry cliff exposing two bedrock layers, Jordan Sandstone and Saint Lawrence Shale. A spring at end of the cove bubbles into a “crystal” clear pool which overflows down the cliff to Zavoral’s Creek below. The steep walls of the gorge, the waterfall, and the lush vegetation join to create an alluring natural attraction.
Four species with conservation status in Minnesota have been seen here: butternut, an endangered species; and American ginseng, Louisiana Waterthrush, and Red-shouldered Hawk, all special concern species.
River Terrace Prairie SNA features a rare gravel prairie on a terrace above the Cannon River valley.
The northwest-facing slope of the terrace is the best place to view native wildflowers in the spring. Visit in early May to see blooming American pasqueflower, mid-May for prairie smoke and kittentails, and late May for fringed puccoon and prairie violet.
The old field below the terrace is a work in progress. Recent management activities in this area include cutting and stacking eastern redcedar and mowing down other woody species. A prescribed burn north and east of the terrace was conducted in the spring of 2017.
Many species of orchids are found in Minnesota prairies, but only three are prairie specialists: western prairie fringed orchid, Great Plains ladies’ tresses, and small white lady’s slipper. They all occur in lime-rich sediments deposited by glaciers and in clay-rich soils of glacial lake beds.
Small white lady’s slipper (Cypripedium candidum) is widely scattered but uncommon across the Great Lakes states to the Dakotas and adjacent Canadian provinces. Minnesota is the core area of the species and may have more individual plants than all other states and provinces combined. It is found in relatively undisturbed, high-quality prairies in the western, southern, and metro regions of the state.
Small white lady’s slipper produces small flowers that are easily overlooked. The best time to see it in bloom is … right now, the last week of May in southern Minnesota and the first or second week of June in the north.
Photo by Bill Reynolds
Sigmoid prominent (Clostera albosigma) is a medium-sized, heavy-bodied, nocturnal moth. It is the most common of the four Clostera species found in Minnesota. Adult moths are found from mid-May to mid-August in deciduous woodlands and forests, and in shrubby wetlands and fields.
A sigmoid prominent adult has grayish-brown wings, a dark brown head and upper thorax, and on the male, a dark brown tuft at the end of the abdomen. The wings are crossed by four pale lines. A dark, chestnut-brown area near the end of the forewing is sharply delineated by a prominent white “S”-shaped bar. The species name albosigma means “white S” and refers to this marking. Spring individuals are darker with more highly contrasting markings. Summer individuals are paler and less conspicuously marked.
The caterpillar feeds mostly on quaking aspen, but also on poplar and willow, and sometimes on alder, birch, maple, and elm. It is a solitary feeder. During the day it curls up a leaf of a host plant and sticks it together with silk webbing, make a shelter where it can feed in safety. Adults do not feed.
Photo by Kirk Nelson
Morel mushrooms (Morchella spp.) are some of the best known and most sought after wild mushrooms in North America. They are particularly abundant in the upper Midwest. They are edible, considered delicious, and are hunted for in deciduous woodlands every spring. False morels (Gyromitra spp.) look superficially similar and appear at the same time of year in roughly the same areas. However, false morels are poisonous. They contain the chemical gyromitrin, which is metabolized in the body into a volatile chemical used as a rocket propellant.
Gabled False Morel (Gyromitra brunnea) is the most common false morel in Minnesota and Wisconsin. It is found in the spring, alone or in groups, on the ground under hardwood trees. The cap is tan to reddish-brown, 2″ to 4″ wide, and loosely wrinkled. It is usually saddle-shaped or winged, divided into 2 or 3 strongly projecting lobes that are fused to each other.