Monthly Archives: November 2015

Oak flake gall wasp (Neuroterus floccosus)

oak flake gall wasp

There are over 750 species of gall wasps (Family Cynipidae) in North America. They are all tiny and look pretty much alike. Fortunately, most can be identified by the appearance, location, and host species of the abnormal growths (galls) their larvae produce.

Oak flake gall wasp (Neuroterus floccosus) galls are found on the underside of leaves of bur oak and swamp white oak. They occur singly though there are usually several galls on any one leaf. They are hemispherical, thickly hairy, and ⅛″ to 3 ⁄16″ in diameter including the hairs. The hairs are white at first but soon turn brown. Each gall contains a single chamber and a single wasp larva. It is revealed on the upper leaf surface as a smooth blister-like bump.

Pure green augochlora (Augochlora pura)

pure green augochlora

There are more than 2,000 living species of sweat bee (Family Halictidae) worldwide. They are so named because they are attracted to the sweat of humans. Fortunately, they seldom sting and when they do the sting is minor.

There are four species of Augochlora in the United States, only one of which is found in Minnesota. Pure green augochlora (Augochlora pura) is a moderately-sized, solitary, metallic green sweat bee. It is very common in the eastern half of North America west to Minnesota. It is found from April to October in woodlands and nearby thickets and pastures.

The overwintered mated female emerges in April. Using an existing insect burrow in dead wood as a starting point, she digs a nest consisting of many branched burrows. She places a pollen ball and nectar in each burrow then lays a single egg on the pollen ball. The first generation offspring emerge as adults in June. By the end of June they have constructed their own nests. The larvae or pupa of the last generation overwinter and emerge as adults the following spring. Adult females overwinter beneath rotting logs in a state of diapause. Males die in the fall.

Sweat bees are identified by a short tongue with a short, pointed last segment; single groove below the base of each antenna; lobe at the base of the hindwing longer than the submarginal cell; and basal vein on the wing strongly arched. Pure green augochlora is distinguished by the completely bright metallic green or coppery body; abdomen not conspicuously striped; dark brown, oval-shaped structure at the base of each wing; wing with three submarginal cells, the first longer than the third; marginal cell of the wing squared off at the end; and upper margin of the plate on the upper lip intruded upon by lobes of the plate above it.

Four-spotted skimmer (Libellula quadrimaculata)

four-spotted skimmer

Four-spotted skimmer (Libellula quadrimaculata) is common, widespread, and misnamed.

Eight-spotted skimmer has two large spots on each wing for a total of eight. Twelve-spotted skimmer has three large dark spots on each wing for a total of twelve. Four-spotted skimmer has two small dark spots on each wing and one large spot on each hindwing for a total of ten. A more appropriate name might be ten-spotted skimmer (Libellula decamaculata).

Four-spotted skimmer is an early season, medium-sized skimmer. It is found from mid-May to September at the edges of boggy lakes and ponds, fens, and slow streams. It is usually seen perched at the top of a tall emergent plant or a weed, often far from water.

It is easily identified up close by the two dark spots on the leading edge of each wing. It is further distinguished by the bright yellowish-brown color on the thorax and front half of the abdomen of juveniles, amber streak with yellow veins at the leading edge of each wing on juveniles, black patch at the base of the hindwing, and narrow yellow stripe on each side of the abdomen. Unlike other skimmers, the female abdomen is tapered like the males, not parallel-sided.

Ney Nature Center

Ney Nature Center

Photo by Michelle Isaacson

Ney Nature Center is a 446-acre park in Le Sueur County east of Henderson. It is adjacent on the north to Ney Wildlife Management Area and on the south to Henderson Station County Park/River Access. It includes the Minnesota River bluff to the west, the steep ravine of an unnamed, intermittent stream to the south, and prairie to the north.

Ney Nature Center is a hybrid, both a Le Sueur County park, open daily to the public, and a nature center, providing educational events for groups of children. It is one of 70 Minnesota Christmas Bird Count locations. Seventy-two bird species have been sited on bird count days from 1997 to 2014.

Gray birch (Betula populifolia)

gray birch

Gray birch (Betula populifolia) is native to eastern United States and Canada as far west as Illinois. It has been recorded in Minnesota only twice, once in Anoka County in 2013 and again in Itasca County in 2015. In its native range it is an early successional tree colonizing burned areas, abandoned pastures, road cuts, and other disturbed areas.

Gray birch is one of the smallest trees in the northeast, usually no more than 30′ tall and about 6″ in diameter at breast height. It is short-lived, seldom surviving more than 50 years. The resemblance of the leaves to those of quaking aspen (Populus deltoides) is the source of the species name populifolia.

Gray birch is easily identified by the aspen-like triangular leaves with flat bases and long, drawn-out tips. It is also distinguished by grayish-white bark that does not easily peel; dark triangular patches at the base of each branch and branch scar; and male catkins that occur individually, not in groups.

Phomopsis gall on hickory (Phomopsis spp.)

Phomopsis gall on hickory

There are at least 232 species of the fungus Phomopsis. Several of these produce bark galls on bitternut hickory. The galls are identical in appearance making identification of the associated species in the field impossible.

Spores are produced throughout the growing season and are spread by wind and rain splashes. It is believed that spores infect a host by entering a wound of a young twig. The fungus then spreads to branches and to the trunk. The galls do not kill the host but reduce vigor and girdle small branches causing dieback. Uninfected trees may occur near heavily infected ones.

Galls may occur singly or in clusters on the trunk and branches. They are woody, rough, more or less round swellings. They appear as tight clusters of nodules. They can be very small to 10″ in diameter. If cut open they reveal disorganized woody tissue but no insect chambers or tunnels.

Olive-sided Flycatcher (Contopus cooperi)

Olive-sided Flycatcher

Olive-sided Flycatcher (Contopus cooperi) is a medium-sized tyrant flycatcher (family Tyrannidae) but a large “flycatcher” as that common name is applied. Only Great-crested Flycatcher is larger. It has the longest migration of any North American flycatcher. Breeding grounds are the Rocky and Cascade Mountains from Texas to Alaska, across Canada and the northern border states to Newfoundland and Vermont. In Minnesota the breeding range includes the northeast third of the state. Wintering grounds are mostly in Panama and the northern Andes Mountains from northern Venezuela to western Bolivia.

Olive-sided Flycatcher is the only North American flycatcher to feed exclusively on insects caught in flight. When feeding it perches at the top of a tree or on a dead branch, launching occasionally to catch a flying insect in the air, and returning often to the same perch. Small insects are consumed in the air. Larger insects returned to and beaten against the perch to subdue.

Flycatchers are notoriously difficult to identify by plumage alone. Olive-sided Flycatcher is one exception to this rule. It is easily identified by its white breast and contrasting dark “vest”. It is further distinguished by its large size; indistinct pale wing bars; whitish undertail coverts with well-defined, dark, V-shaped markings; and inconspicuous eye ring.

Peeling Puffball (Lycoperdon marginatum)

Peeling Puffball

Peeling Puffball (Lycoperdon marginatum) is a common and widespread, medium-sized puffball. It appears on the ground, individually, scattered, or in groups, usually in sandy soil. It is often found in the woods under deciduous or coniferous trees, but is also found in the open on roadsides and in waste places.

The skin is covered with short, erect spines that often aggregate in groups of 2 to 4 creating pyramid-shaped warts. As it ages, the outer, warty or spiny skin sloughs off in thick, irregular patches or chunks revealing the smooth, pale to dark brown inner skin below. When mature, a pore-like mouth develops at the top through which spores are released.

Peeling Puffball is distinguished by the outer skin that is covered with pyramidal warts and sloughs off in thick, irregular patches or chunks.

green frog (Rana clamitans)

green frog

Green frog (Rana clamitans) is a mid-sized true frog, the second largest frog in Minnesota after only the American bullfrog. It is common throughout the eastern United States, less common in Minnesota where it is at the western edge of its range. It is an aquatic frog, found in large marshes, streams, deep ponds, larger lakes, and roadside ditches.

Green frogs are often seen on a shore within one quick leap to a body of water. They hunt by sitting still and waiting for prey to cross their path. The mating call can be heard from May through July. It is usually described as the sound of plucking a loose banjo string, “plunk”. The call is a single note but is often repeated. No other frogs in Minnesota sound similar.

Green frog is distinguished by the large size; the prominent back ridges (dorsolateral folds); and the fourth toe on the hind foot, which is not webbed beyond the second joint.

Bold jumper (Phidippus audax)

bold jumper

Photo by Terry Hayes

Bold jumper (Phidippus audax) is an extremely common jumping spider in eastern United States. It is a medium-sized spider but a very large jumping spider. It can be found from spring to fall in old fields, prairies, open woodlands, backyards, gardens, and human houses.

The most distinctive feature of this spider is the iridescent green or blue mouthparts. Both sexes share this feature, but when courting, the male will wave its forelegs and sense organs (palps), showing off his colorful parts.

Bold jumpers hunt during the day, not at night. They sneak up on their prey and pounce, releasing silk while jumping as a drag line to prevent falling. They will bite if molested but are usually too quick and wary to be caught. They can jump 10 to 50 times their body length.

There are about 5,000 species of jumping spiders. Bold jumper is distinguished by its large size; conspicuous, iridescent green or blue mouthparts; massive, high, front body segment with rounded sides; four pairs of matte black spots on the abdomen; the arrangement of usually four pairs of white spots on the abdomen; and its occurrence in the northern United States.