A detour

On one of the days during my vacation last July I headed for Finland, Minnesota to follow the Heffelfinger Road. This would connect me with Cloquet Lake Road and from there to a little lake named Drake Lake. But as I left Finland there was a sign that said the road was closed ahead due to bridge reconstruction. I continued on a bit and saw the bridge was definitely not there anymore.

The day was still young so, I turned around and headed to Highway 11 where I knew of another way to get to Drake Lake albeit more difficult. This was the Beaver River Road and by following it north I would be able to connect to Heffelfinger Road and avoid construction. After a few miles, a sign appeared saying “road closed ahead”. Apparently another bridge was being repaired. But there was still one more way to get to Drake Lake.

This alternate route was Forest Road 102 which would connect me with Camp 26 Road where Drake lake was located. Forest Road 102 was a rough ride with many deep puddles straddling the road, ruts, and large rocks. I think my average speed was about 5 mph.

Finally, I got to Camp 26 Road. Nothing looked familiar. So much had changed since I was last there in 1995 including Forest Road 102 which was more like a two-rut road back then. Much of the forest had been cut down in the intervening years and there are now many gated driveways to hunting cabins. I never did find Drake Lake that day although I probably drove right by it. You can’t see it from the road as it is hidden by about 500 feet of dense forest.

Drake Lake is one of many small lakes in northern Minnesota gradually turning into a peatland, a centuries-long process. The water is dark brown like strong coffee from tannic acids leaching from deposits of peat. Surrounding Drake Lake is a floating fen thick with sphagnum and stunted leatherleaf shrubs. On the north side of the lake is a white cedar forest.

Patches of pogonia, clubspur, and dragonhead orchids, beaked rushes, yellow-eyed grass, and bladderwort plants grow on the floating peat mat. When in bloom these decorate the floating mat with masses of pink, white, yellow, and rusty brown flowers. I’ll be back there next year and hopefully, the bridges will be repaired by then. If not I’ll take Forest Road 102 again.

I did find other interesting spots along the road. One of these was a long patch of spreading dogbane with dozens of butterflies nectaring on the sweet flowers. So I spent some time there trying out a new camera lens. Above and below are a few of the species I was able to identify.

Arctic Skipper

Carterocephalus palaemon, Arctic Skipper, widespread in Minnesota. It was previously known from Carlton County by a historical record. There do not seem to be any recent records from the county other than this one.

 

This small butterfly with dark brown wings and yellow spots is the Arctic Skipper (Carterocephalus palaemon). I saw it a few days ago on a warm, sunny, and humid afternoon on June 12. It was resting on a blade of grass in a sunny opening in an encroaching forest. Although the Arctic Skipper is widely distributed and ranked a G5 or “globally secure” there is only one record that I could find of it from Carlton County and it is historical but there was no information about when or where it was seen or who saw it.

Taxonomy
Class Insecta (Insects)
Order Lepidoptera (Butterflies and Moths)
Superfamily Papilionoidea (Butterflies and Skippers)
Family Hesperiidae (Skippers)
Subfamily Heteropterinae (Intermediate Skippers)
Genus/species Carterocephalus palaemon

Description
The upper wing surface is dark brown to almost black with roughly rectangular yellow spots. Below they are like the color of a deer fawn and marked with black-rimmed yellow spots. Wingspread is 2.5 to 3.2 cm.

Range
A circumboreal species found in North America from Alaska to Canada’s Atlantic coast and south to California and Pennsylvania. Not truly an Arctic species.

Larval Host Plants
Larvae of Carterocephalus palaemon eat grasses. In California purple reedgrass (Calamagrostis purpurascens) is reported as a larval host. In some European countries, brome (Bromus spp.) are preferred larval hosts.  Purple moor-grass (Molinia caerulea) has been reported as a larval host in Scotland. Purple reedgrass is rare in Minnesota and purple moor-grass does not grow here. There are bromes both native and introduced in the state as well as the native Canada bluejoint grass (Calamagrostis canadensis). It is likely that Carterocephalus palaemon larvae feed on other grass species besides the few mentioned in the literature.

 

SOURCES
Arctic Skipper Carterocephalus palaemon (Pallas, 1771) at BAMONA.

Carterocephalus palaemon (Pallas, 1771) at the Bourgogne-Nature website.

Chequered Skipper (Carterocephalus palaemon) at the Sottish Natural Heritage website.

Species Carterocephalus palaemon – Arctic Skipper – Hodges#3982 at the Bug Guide website.

 

A butterfly

Mustard White Butterfly (Pieris oleracea)
Mustard White Butterfly (Pieris oleracea)

 

I saw this butterfly yesterday while working in my garden spreading old hay around rhubarb and currant bushes. It had probably just emerged from its chrysalis earlier in the morning and was finishing up drying its wings. The butterfly is the Mustard White Butterfly (Pieris oleracea) a species native to North America and occurs in Canada from the Northwest Territories south to Alberta and then east to the Atlantic seaboard. In the US it can be found from North Dakota to Maine.

The green larva with a single white or pale yellow lateral line and small black spots feed on members of the mustard family (Brassicaceae), such as rock cress (Arabis spp., Boechera spp., and Draba spp.), cuckoo flower and bittercress (Cardamine spp.), and toothwort (Dentaria spp.). There are usually two or three generations a summer with the last generation overwintering as a chrysalis.

Adult Mustard White Butterflies come in a spring and summer forms. The one in the photo is the spring form. Summer forms have less dark shading on the wing upper surfaces and the lower surface veins are also less dark. Adults feed on nectar usually from mustard family plants.

Previously Mustard White Butterfly was considered to be in the species Pieris napi, a European species commonly called the Green-veined White. They are regarded as distinct enough to be classed as separate species although some authorities consider the North American P. oleracae to be a subspecies of P. napi (synonym Artogeia napi) calling it Pieris napi subsp. oleraceaP. oleracae differs from P. napi by having chalky white upper wings while P. napi has dark spots and dark margins on the upper wings. Another difference is the tolerance of P. napi for garlic mustard (Alliaria petiolata) which is toxic to the larvae of P. oleraceae and thus a serious concern for the species survival where this plant occurs in North America to which it is not native.

Taxonomy

Insecta (Insects)
Order Lepidoptera (Butterflies and Moths)
Superfamily Papilionoidea (Butterflies and Skippers)
Family Pieridae (Whites, Sulphurs, Yellows)
Subfamily Pierinae (Whites)
Tribe Pierini (Cabbage Whites, Checkered Whites, Albatrosses)
Genus/species: Pieris oleracea

SOURCES

Bowden, S. R. (1979). Subspecific Variation in Butterflies: Adaptation and Dissected Polymorphism in Pieris (Artogeia) (Pieridae). Journal of the Lepidopterists’ Society
33(2):77-111.

Heinen R., Gols R., and Harvey J. A. (2016). Black and Garlic Mustard Plants Are Highly Suitable for the Development of Two Native Pierid Butterflies. Environmental Entomology, Vol. 45 (3):671–676.

 Mustard White (Pieris oleracea) (Harris, 1829) at the Canadian Biodiversity Information Facility website.

Pieris oleracea at the Wikipedia website.

Species Pieris oleracea – Mustard White – Hodges#4195.1 at the Bug Guide website.

 

 

 

 

 

 

 

A Winter of Mothing

 

 

 

 

I’ve been going through my photos of moths from last summer and fall while the snow here slowly melts, comes back again, and then melts some more. As I go through my files of moth photos I am beginning to realize that there may be several hundred moth species in my township. At last count (March 30) I have 147 identified to species and another 175 unidentified species for a total of 322 species. That is a little bit over my original estimate of 300 species in my township. I am going to have to revise that number upwards a bit. The current estimate of moth species in the state of Minnesota where I live is placed at 1,503 so there may be another 300 or more species on top of what I have found.

Digital photos of the unidentified moths are kept in folders named Crambids (23 subfolders, some shown above), Micro-moths (35 subfolders, some shown above), Darts and Prominents (50 subfolders), Tussock Moths (6 subfolders), and many as just “Moth” (55 subfolders) for those in the Geometridae or moths I can’t place in any group. I think I may break that one up into “Geometrids” and “Others”.

There are still many more photos to sort through and the next group to be separated are the Plume Moths (Pterophoridae). This is an interesting group of moths that look like some sort of fixed-wing aircraft. There are three Plume Moths species subfolders (see below) but more might be added later. Moth caterpillars and cocoons also have their own folder called “Unknown Caterpillars” with just three species left until I find more this summer.

 

 

 

Now that I have some of the moths separated and each in its own folder I can begin tackling identification in a more systematic way. Of course no single field guide or website will have all the species possibly present in a geographic region but by getting these photo specimens identified to family or better yet to genus I can narrow my search efforts and maybe hit upon the answer. Right now I am working on the Crambidae or Crambid Moths commonly known as Grass Veneers and Snout Moths. A few days ago the unidentified Crambid files had 29 unknowns. Now it is down to 23 unknowns after confirming three species (Crambus bidens, C. agitatellus, and Chrysoteuchia topiarius) and tentatively identifying three more (Crambus pascuella, C. perlella, and Microcrambus elegans). It is progress.

More progress below with two moth larvae tentatively identified (Acronicta impressa, Melanchra assimilis) and three with more confidence (Trichordestra legitima, Erannis tiliariaPyrrhia experimens). To that I should add that I have found two errors in my checklist but these are now corrected. One was in the right genus (Eucosma) but wrong species (E. dorsisgnatana not E. similiana both very similar) and the other was a species in a look-alike genus (Macrochilo litophora not Zanclognatha pedipilalis).

 

 

 

Warm weather is still in the future it seems but when it does get here and the ice and snow start to melt I will be out in the woods and fields looking for moths and other things that are waking up after a long and sometimes cold winter.