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.