A Moth Among the Ferns

Northern Petrophora (Petrophora subaequaria)


I was out taking a walk Sunday afternoon and saw many different small moths flying out from hiding in the grass and blueberry bushes. Most were too small and fast to get a good look at them. The one shown above flew and ducked under some grass blades just long enough for me to get a few snapshots before it took off. Later I went out again and saw dozens of them in a forest clearing full of bracken fern. The species is Northern Petrophora (Petrophora subaequaria, Family Geometridae) and its larvae feed only on ferns with bracken fern (Pteridium aquilinum) apparently the principle host plant. Photos at Bug Guide show the larvae on fronds of Osmunda fern.


Some brief information on Northern Petrophora (Petrophora subaequaria)

Superfamily Geometroidea (Geometrid and Swallowtail Moths)
Family Geometridae (Geometrid Moths)
Subfamily Ennominae
Tribe Lithinini
Genus/species Petrophora subaequaria

Wing span to 19 mm, speckled tan forewings with yellowish veins, antemedial and postmedial lines white edged and parallel. There is a small black dot in the center of the wings.

Life cycle
As with many moths not directly injurious to crops and forestry there is little information on the life history of Northern Petrophora. With so many adult moths appearing now in my bracken field it seems that mating and egg laying occur in the spring.

Northern Petrophora occurs in North America from New Brunswick to Alberta, along the Great Lakes east to New England, and then south sporadically along the Appalachians to North Carolina.



Beadle, D. and Leckie, S. (2012). Peterson Field Guide to Moths of Northeastern North America. Houghton Mifflin Harcourt Publishing Company, Boston. 640 pages.

Voss, Edward G. (1991) “Moths of the Douglas Lake Region (Emmet and Cheboygan Counties), Michigan: IV. Geometridae (Lepidoptera),” The Great Lakes Entomologist: Vol. 24 : No. 3 , Article 11. Available at: http://scholar.valpo.edu/tgle/vol24/iss3/11

Species accounts at Bug Guide, Moth Photographers Group, HOSTS,




A Mystery Solved


This orange organism growing the surfaces of fallen leaves in the woods has stumped me for years. I had long thought it was some sort of slime mold (Myxomycota) and every spring when I saw the little orange patches it forms on dead leaves and deer dung in the forest I would go searching websites to find out what this strange slime mold was. I never did figure it out until today when I looked very carefully at the cup-like structures and thought that maybe this is no slime mold but a fungus in Ascomycota (cup fungi). Within a few minutes I came across several photos of an orange fungus that looked very similar to this one. Not only that but I solved another new mystery which was the white fungus with brown cups growing with the orange one. The answer to both mysteries was found at Sociedad MicológicaI Extremeña.


The orange fungus is Byssonectria and the white one with dark brown cups rimmed with lighter brown is Pseudombrophila. Both are “vernal” fungi, that is, fungi that fruit in the cooler part of early spring. As for whether one is being eaten by the other it only looks that way. These species grow in the forest on animal dung and where animals (deer in this case) have urinated. The Byssonectria may be B. terrestris (see key) but I have not found out what the other one is apart from Pseudombrophila. Both species are classed in:

Kingdom – Fungi
Phylum – Ascomycota
Class – Pezizimycetes
Order – Peziales
Family – Pyronemataceae



Bysonectria terrestris at Sociedad MicológicaI Extremeña.

Harmaja, H. ( 986). Studies on the Pezizales. Karstenia 26: 41

Pfister, D. H. (1993). A Synopsis of the North American Species of Byssonectria (Pezizales) with Comments on the Ontogeny of the Two Species. Mycologia, 85(6): 952-962.

Seaver, F. J. (1951). The North American Cup-fungi (Inoperculates). Published by the author.

A Few More Spring Flowers


More flowers on shrubs and trees from around here. Trees like red maple (Acer rubrum) and quaking aspen (Populus tremuloides) and shrubs such as tag alder (Alnus incana), hazel (Corylus spp.), and willow (Salix spp.) are the first flowers of spring appearing before the more familiar spring ephemeral wildflowers that grow in forests.

Soon there will be other flowers in bloom. Hepatica (Anemone americana), stalked sedge (Carex pedunculata), and wood rush (Luzula acuminata) will come into flower in the next few days. These low growing plants occupy spaces on the forest floor and today on one of my rambles I noticed that many already have unopened flower buds.

Spring Flowers



It is April and spring is should to be well underway with flowers in the woods, trees putting out leaves, bees flying about, and frogs calling from the woodland ponds. But here in northern Minnesota you wouldn’t know it with the cold weather, occasional snow, and bleak landscape with only the conifers for greenery. There is still snow in the woods where the trees are thick and block the sun. The ground remains frozen except in the sunniest of sites and so none of the forest wildflowers have come out of dormancy. Even so, trees and shrubs are beginning to awaken albeit about 30 days late. The earliest of these are tag alder (Alnus incana ssp. rugosa), American hazel (Corylus americana), beaked hazel (C. cornuta), and tea-leaf willow (Salix planifolia). Following closely is the quaking aspen (Populus tremuloides) but only some groves (clones really) are flowering. Red maple (Acer rubrum) flower buds are swelling and I expect they will be in full bloom in a week. So far none of these shrubs or trees have produced any leaves. That will come later when flowering is over and temperatures are warmer at night.

Trees that flower in the early spring are mostly wind-pollinated a good strategy since insects may still be in hibernation or slow to move about. Tea-leaf willow is an exception and produces abundant pollen and nectar which attracts small wasps, solitary bees, beetles, and flies. These insects pick up pollen from the staminate flowers and transfer it to the pistillate flowers. Tea-leaf willow plants are either staminate or pistillate so the insects need to go from one to the other in the right order to effect pollination. The flowers of tea-leaf willow are fragrant and so lure the insects to them. But if insects are scarce like they are this year tea-leaf willow can still pollinate some of its flowers by wind pollination. Red maple is insect pollinated and has thick nectar-secreting glands in its bright red flowers to attract bees and other nectar feeders of many kinds. For a few days there will be a red glow in the forest canopy while the red maple is bloom.

Rain is forecast for early next week but the chances for a good downpour are very low. This is not a desirable situation as the low humidity, dry grass, and constant winds make fires more likely. A couple of rainy days and nights would certainly reduce the chances of a fire. Sunny weather isn’t all it’s cracked up to be.

So far I have heard no frogs in the woodland ponds and am wondering where they are. In past years wood frogs have begun calling in mid-April even when there was a bit of ice on the ponds. There ought to be some by now with the warm weather. I hope this isn’t an indication of a problem.





A caddisfly species

Glyphopsyche irrorata


The insect above is a caddisfly and one of many caddisfly species that live in northern Minnesota. Caddisflies (Order Trichoptera) are typically active during the warm months of summer and early fall but this caddisfly was active on the evening of April 25 when air temperatures were in the low 40s. It took me about a couple of days to figure out the species after searching Bug Guide and comparing photos (compare the pattern on the ends of the wings with this) and then doing a literature search. This caddisfly is Glyphopsyche irrorata which is in the Family Limnephilidae and is interesting for a few reasons the first of which is its mode of surviving the winter. Larval Girrorata live in small ponds such as vernal pools and peatland ponds, shallow marshes, and slow moving streams that may dry up by the end of summer. Many caddisfly species in similar habits lay eggs in gelatinous masses under moist objects in the drying water body where the larvae remain until favorable conditions return. Girrorata has a different survival strategy. It goes through a rapid larval development after the eggs are laid in May, pupates in August, and emerges as an adult in September. Mating takes place in the autumn and then the adults go into hibernation until the following spring (more mating may take place then) when the females lay eggs in small ponds and slow moving streams. The larvae build cases from bits of organic material and mineral material and are detrivorius shredders feeding on decaying wood and other organic matter.

Another reason Girrorata is interesting, at least from the standpoint of where this one was found, is that this species has been recorded only twice in Minnesota in 41 years. The first time was in 1977 in Clearwater County and the second was in 2000 in Cook County. This sighting makes the third time and in a new county. Although not on Minnesota’s rare species list it must be uncommon to have only two previous records in the state. This is in spite of several caddisfly surveys conducted in the state in the last 20 years. The range of Girrorata is Nearctic extending from Newfoundland to Alaska and south to California, in the Great Lakes Region and then east to New Hampshire and Maine. The number of known sites where Girrorata occurs in Wisconsin, Michigan, New Hampshire, and Maine are few.

Girrorata is attracted to lights as are many caddisflies. It is also attracted to sweet liquids like maple sap in tapping buckets. Many caddisfly species that fly during the summer are nectar and sap feeders, too. Using a combination of lights and sweet liquids might be a way to attract this species.


The forewings are grayish chocolate-brown with small spots and many larger translucent patches. Length is about 16 mm.


Order: Trichoptera

Superfamily: Limnephiloidea

Family: Limnephilidae (Northern Caddisflies)

Subfamily: Limnephilinae

Tribe: Chilostigmini

Species: Glyphopsyche irrorata


Berté, Stephen B., and Gordon Pritchard (1983). The Life History of Glyphopsyche Irrorata (Trichoptera, Limnephilidae): A Caddisfly That Overwinters as an Adult. Holarctic Ecology, Vol. 6, No. 1: 69-73. JSTOR, http://www.jstor.org/stable/3682718.

Betten, Cornelius. (1934). The caddis flies or Trichoptera of New York State, Bulletin of the New York State Museum No. 292:1-576.

Casey Scott and Jeffrey Dimick. A Distributional Atlas of Riffle Insects from Wisconsin Streams. Aquatic Biomonitoring Laboratory, University of Wisconsin-Stevens Point. 437 pp. © 2010.

Chadde, Steve W., Shelly, J. Stephen, Bursik, Robert J., Moseley, Robert K., Evenden, Angela G., Mantas, Maria, Rabe, Fred, and Heide, Bonnie. Peatlands on National Forests of the Northern Rocky Mountains: Ecology and Conservation. 80 pages. United States Department of Agriculture, Forest Service, Rocky Mountain Research Station. General Technical Report. RMRS-GTR-11 July 1998.

Houghton, David C. (2012). Biological diversity of the Minnesota caddisflies (Insecta, Trichoptera). ZooKeys, Vol. 189:1-389. doi: 10.3897/zookeys.189.2043.

Houghton, David C., DeWalt, R. Edward, Pytel, Angelica J., Brandin, Constance M., Rogers, Sarah E., Ruiter, David E., Bright, Ethan, Hudson, Patrick L., and Armitage, Brian J. (2017). Updated checklist of the Michigan (USA) caddisflies, with regional and habitat affinities. ZooKeys Vol. 730: 57–74. doi: 10.3897/zookeys.730.21776 http://zookeys.pensoft.net

Majka, Christopher G. (2010). Insects attracted to Maple Sap: Observations from Prince Edward Island, Canada. ZooKeys Vol. 51:73– 83. doi: 10.3897/zookeys.51.478.

Nimmo, Andrew P. ( 1971). The adult Rhyacophilidae and Limnephilidae (Trichoptera) of Alberta and eastern British Columbia and their post–glacial origin. Quaestiones entomologicae, Vol. 7:3-234.

Species Glyphopsyche irrorata at BugGuide.Net.

UNH Insect and Arachnid Collections – Record Detail Glyphopsyche irroata. University of New Hampshire Department of Biological Sciences.

Wiggins, Glenn C. and Parker, Charles R. Caddisflies (Trichoptera) of the Yukon, with Analysis of the Beringian and Holarctic Species of North America, pp. 787-866 in Danks, H. V. and Downes, John A. (Eds.), Insects of the Yukon. Biological Survey of Canada (Terrestrial Arthropods), Ottawa. 1034 pp. © 1997.

Some new moths

Agonopterix argillacea


The tiny gray moth in the photo above is one of the latest moth finds here this month. I’ve seen several of these moths in the last week flying just above the ground or walking on the snow. Some even came to my porch light one warm night (April 22) with an air temperature of 46° F and also my kitchen so I was able to photograph them. They are Agonopterix argillacea. Adult moths in this genus aestivate during the winter and emerge in the early spring to lay eggs. The larvae of A. argillacea feed on willows (Salix spp.) which are abundant in the wetlands around here.

Besides A. argillacea other species of moths are showing up as the temperatures get warmer. By “warmer” I mean between 32° F and 40° F.  The three moths shown below were found flying just above the snow when air temperatures were almost 40° F in the early morning (April 18 and 22) and late afternoon (April 22) as the sun was setting. I have not been able to identify them despite going through hundreds of photos at the Moth Photographers Group and Bug Guide websites. One may be in the genus Apotomis.



On Sunday night (April 22) when the air temperature was 46° F (after almost reaching 70° F during the day) I turned on my porch light and two individuals of this large moth came to the light. I am not certain of the species but it looks like an Orthosia. I’m going to take a break from trying to figure this one out.



Ctenucha Moth (Ctenucha virginica) and other caterpillars are also coming out of hibernation venturing out onto the snow it seems not wanting to wait for the really warm weather. I found this Ctenucha Moth caterpillar (below) and several others in the late afternoon (April 22) on some icy snow floating in a flooded field. They were soaked and looked dead but after a few minutes in my hands perked up so I moved them to some higher and drier ground. Ctenucha Moth caterpillars overwinter as immature larvae. When warm spring weather comes back they emerge from hiding and begin to eat grasses and sedges their primary food plants. In a few weeks they are fully grown and pupate. By early summer the Ctenucha Moths hatch from their pupa to start the process over. Ctenucha Moths are in the Subfamily Arctiinae which includes the familiar Woolly Bear (Pyrrharctia isabella).



This next fuzzy caterpillar was found on April 19th crawling across the snow in a sedge marsh. The caterpillar, whose species identification is unknown but may be related to the Ctenucha, seemed to have no problem with the cold. I watched it for a little while until it reached a clump of exposed sedge and then went inside. It is fascinating to me that these cold-blooded animals can function just fine when ambient temperatures are only a few degrees above freezing and snow is still on the ground.



Now that most of the snow is gone it is becoming harder to find these tiny moths. But soon other species will emerge as the days get warmer and plants start to grow.

A hundred times wider in one day


Temperatures rose rapidly over the weekend melting three feet of snow in our watershed. The result is a huge flood and the little stream (West Fork of the Moose Horn River) that flows through my property has gone from 16 feet wide to almost 1,600 feet wide. Water depths have increased from 3 feet to about 6 or 7 feet depending on where you measure. And the speed of the stream’s flow has also increased although I have no measurements for that other than sore muscles from trying to paddle upstream so as not become part of the flotsam.

The rising and spreading waters clean out the stream and refresh it. They also flatten out the grasses and sedges in the shrub carr/sedge meadow making them less prone to fire. And for me they make it easier to visit the western sections of my property as I can canoe within 100 feet of the uplands. When the stream is at normal levels the walk is 1,300 feet through willow thickets and sedge tussocks.


The edge of the flood comes up to my backyard and is just three hundred feet from the stream and deep enough for the canoe.


The flood waters are stirring up many small aquatic animals which can be collected in simple traps like minnow traps. It is encouraging to find larvae of damselflies and caddisflies in the traps as most species from these insect orders require oxygen-rich waters to survive. Their presence and abundance indicates a good level of stream health. But not everything in my traps is an indicator of  oxygen-rich water. Mudminnows (Umbra limi), Brook Sticklebacks (Culaea inconstans), and isopods (most seem to be Caecidotea) are tolerant of oxygen-poor water. When rainfall is abundant and regular the stream is full and the water fresh. But if rainfall is scarce or sporadic the stream’s water levels drop and the flow slows down. During drought years the stream will nearly dry up. This can be especially problematic in the winter when what little water there is freezes solidly to the stream bed. These conditions put a lot of stress on aquatic life and species that can tolerate that stress have a better chance of surviving. In recent years rainfall has been more consistent. The arrival of beavers, which had been gone for two decades, is also helping to keep water levels higher and creating new aquatic habitats where other animals and plants can live.



While the water is high many migratory waterfowl have arrived. Trumpeter Swans (Cygnus buccinator) and Hooded Mergansers (Lophodytes cucullatus) are two species that arrived this week. They will rest here for a short while and continue northward to their preferred nesting habitats.  A pair of Canada Geese (Branta canadensis) and Sandhill Cranes (Antigone canadensis) have come back as have several pairs of Mallard Ducks (Anas platyrhynchos). These birds will stay here all summer tending their young. Redwing Blackbirds are back, too, fussing at intruders into their territory like me. Other songbirds, mainly warblers and sparrows, will being showing up soon to build nests in the willows and sedge. The flood will continue for several more days and eventually the shrub carr/sedge meadow will drain a little. Then the willows, grasses and sedges will start leafing out transforming the scene from one of bare twigs and brown thatch to green dotted with patches of aster and goldenrod flowers.



The flood at sunset.