The Scarce Infant Moth really is scarce

I saw this *Leucobrephos brephoides* on March 30, 2006. Even though I look for it each spring, I have never seen it again. When I found it, the marsh it was in was beginning to flood, snow and ice were still on the ground, and the air temperature that day was in the mid-30s to low-40s F. This is a hardy moth.

Leucobrephos brephoides is a rare moth species in the family Geometridae, subfamily Archiearinae. I have seen it only once, back in March 2006. Even though I look for it every year in late March and early April, I have not found it again.

The one and only time I have seen it, there was still snow on the ground, although it was melting. In the marsh where it was resting on some grass, a flood was beginning. And it was chilly, in the mid-30s to low-40s F. For Leucobrephos brephoides, this was a normal day.

I was excited to find this little moth. It was cold and there was still snow on the ground. I’d never really thought of insects being active so early. Since then, I have found that many insect species, beetles, moths, wasps, and midges, are active this early. Even spiders are out. Some insects are feeding on nectar and pollen from early-flowering willows. Others are seeking mates. A few, along with the spiders, are hunting other insects.

Description

The forewing of Leucobrephos brephoides is black and dusted with grey. The postmedial line is black with a white border. The antemedial line is also black but lacks a white border. The hindwing is white with an even black margin and basal black scaling.

Males have pectinate (feathery) antennae, the females have filiform (thread-like) antennae.

*Leucobrephos brephoides* on March 30, 2006

Life history

In the spring, female Leucobrephos brephoides lays 1 to 3 eggs on a leaf scar near the tips of aspen branches. They may lay their eggs thirty or more feet from the ground or just a few feet from the ground. After about 15 days, the eggs hatch. The larvae go through five instars before burrowing into the soil and pupating.

In the spring, the adults emerge from their pupa. Adult Leucobrephos brephoides are day fliers and active even while temperatures are still cold and snow is still on the ground.

**Catkins of quaking aspen (*Populus tremuloides*)**

Habitat and host plants

Leucobrephos brephoides inhabits open mixed broadleaf and coniferous forests. Its primary host plant is quaking aspen (Populus tremuloides), but it also feeds on paper birch (Betula papyrifera) and alder (Alnus incana). Larvae have also been found feeding on willow (Salix spp.) and balsam poplar (Populus balsamifera). All of these species produce catkins in the early spring before their leaves emerge. Catkins may be an important food source Leucobrephos brephoides larvae, which hatch from their eggs before leaf emergence.

Leucobrephos brephoides is found in cool northern forests where its primary host plant, quaking aspen, grows.

What do the adult moths eat?

Gibson and Criddle (1916) made some interesting observations about the food preferences of the adult Leucobrephos brephoides. They found that sugar baits did not interest the moths. Instead, they noted that rotten meat was attractive. The moths also sought moisture and could be found on muddy roadways near aspen woods.

Similar species

A similar species, also active when Leucobrephos brephoides is in flight, is Archiearis infans. Archiearis infans is more common and widespread than Leucobrephos brephoides. It has bright orange underwings. I’ve seen this species one time also, and that was in the spring (April 2021) during the day at a mud puddle. It lays its eggs in the spring, and the larvae feed on the same plants as Leucobrephos brephoides.

Other Leucobrephos species

Leucobrephos is a Holarctic genus with two species: Leucobrephos brephoides in the Nearctic and Leucobrephos middendorfii in the Palearctic. Leucobrephos middendorfii occurs in Siberia, Mongolia, and the Ural Mountains. The species Leucobrephos mongolicum is considered a synonym of Leucobrephos middendorfii, as is Leucobrephos middendorfii ussuriensis. The subspecies Leucobrephos middendorfii nivea is considered valid. Host plants of Leucobrephos middendorfii are from the same genera as those of Leucobrephos brephoides.

Range of Leucobrephos brephoides

**The *Leucobrephos brephoides* range map shows a wide range but few records.**

Next year

Next March and April, I’ll be out looking for Leucobrephos brephoides again. I’ll check the edges of the woods and marsh for moths, as I have in previous years. I’ll also check the aspen and willows for eggs and larvae. I’m also going to set out bait stations, some with sugar to mimic sap and others with spoiled meat. Maybe after twenty years, I will finally see this scarce moth again. Or maybe not. It is possible that since 2006, the climate here has gotten too warm for this cold-loving species.

Sources

Wordless Wednesday

Venerable Trees

This white pine is the largest and possibly the oldest tree on my property. It has a DBH (diameter at breast height or 1.3 meters) of 92 cm, and I estimate its age at about 180 years old.

The white pine probably began growing sometime around 1845. This was at the beginning of the white pine logging era in Minnesota. By 1900, it would have been large enough to cut for timber, but it was missed. The 1918 fires that swept through the area also missed it by just two short miles.

All through the 20th century, it continued to grow undisturbed. Over time, a forest of paper birch, aspen, balsam fir, and spruce grew under the pine. Beneath the trees, clubmosses, poverty oats, rough rice grass, purple melic grass, twinflower, and hairy goldenrod covered the ground. The forest had come back.

**The big white pine as seen from ground level.**

When other white pines on this 40-acre section were cut down for lumber in 1960, this huge white pine was not cut down. So were four other large white pines and five large red pines. I don’t know how or why this happened, but I am glad they were overlooked. What would this forest be without them?

One of the big white pine’s neighbors. This **white pine** **tree had a DBH of 82 cm in 2015. I estimate its age at 170 years.**

Logging of Minnesota’s white pine forests began in the 1830s, but it wasn’t until the 1870s, with the advent of railroads and new settlements, that it really took off. By 1900, Minnesota had produced almost 1.2 billion board feet of white pine timber. This was not to last, and by 1929, nearly all of Minnesota’s white pine forests were depleted, bringing white pine logging to an end. While not remnant trees from old-growth forests, these white and red pine trees are survivors from that time.

**One of the old red pines, DBH 56 cm, age estimate 121 years.**

White pines I planted in the early 2000s. These trees were grown from seeds produced by another old and enormous white pine on my land. They are part of my project to re-wild a former hayfield and pasture.

I found some more leaf mines

**A leaf mine in a big-leaf aster leaf that was probably made by the larva of an *Ophiomyia* sp., a genus of leaf-mining flies.**

Recently, I’ve become more interested in leaf mining insects after finding what might be the serpentine leaf mine of a Stigmella moth in a blackberry leaf. This wasn’t the first moth leaf mine I have found. In 2017, I identified another leaf mining moth, Phyllocnistis populiella, recognizing it from its leaf mine in a balsam poplar leaf.

Later, in 2019, I found the adult of another poplar leaf mining species, Phyllonorycter nipigon. Beyond that, my findings of leaf miners have been sporadic and by chance when photographing micro-moths at my moth lights.

Changing weather, changing focus

With the colder fall weather, it is more difficult to find insects and other arthropods. So, now I am turning my attention to the signs of them.

Out on my walks in the woods late last month, I came across five more serpentine leaf mines. The first was in a big-leaf aster (Eurybia macrophylla), which is shown in the photo at the top of the page. The other four were in wild red columbine (Aquilegia canadensis), coltsfoot (Petasites palmatus), goldenrod (Solidago gigantea), and bunchberry (Cornus canadensis). I couldn’t find larvae in any of them, but I think I have a good idea of what made them.

**This leaf mine in a columbine leaf was probably made by a larva of *Phytomyza aquilegivora*.**

Possible identifications

The leaf mine in the aster leaf was probably made by the larva of a species of fly in the genus Ophiomyia, leaf mining flies in the family Agromyzidae.

**Phytomyza *agromyzina* in bunchberry**

While I’m not absolutely certain, the leaf mines in the other four plants were probably made by the larvae of leaf mining flies in the genus Phytomyza, also in the family Agromyzidae.

Columbine: Phytomyza aquilegivora
Bunchberry: Phytomyza agromyzina
Coltsfoot: Phytomyza albiceps group (see page 5)
Goldenrod: Phytomyza solidaginophaga

I’ve probably seen the adult Phytomyza flies, but didn’t give them a second thought, assuming they were just some more pesky flies buzzing around my head looking for blood or sweat. Next year, I’ll be paying more attention.

Leaf mining flies are species-rich

There are at least 600 named species of Phytomyza, making it the largest genus of leaf mining flies in the world. Ophiomyia has over 200 species. Species of Phytomyza and Ophiomyia are host-specific, which accounts for much of the diversity in their genera.

Cerodontha is another species-rich leaf mining fly genus in the Agromyzidae, with 285 species worldwide. Cerodontha is a monocot specialist mining the leaves of sedges (Cyperaceae), soft rushes (Juncaceae), irises (Iridaceae), and grasses (Poaceae). Some Cerodontha species have been found in Minnesota and neighboring Wisconsin.

A quick search of species of Phytomyza and Ophiomyia that might occur in northern Minnesota shows at least twenty species and five species, respectively. The number of Cerodontha species in Minnesota is unknown. I think next summer is going to be an interesting one.