Thursday, September 7, 2017

My Personal National Moth Week, 2017

Given the stormy weather during National Moth Week here in Colorado Springs, I took advantage of the few opportunities to find moths here. The nights of July 24 and 30 I draped a sheet over the door of our backyard shed, hung a blacklight, and hoped for the best. I am rarely disappointed, even if beetles, bugs, and flies are more prevalent than moths.

Identifying what comes in is a real challenge, too. Taxonomy, the classification of organisms, is constantly changing as we learn about new evolutionary relationships. For example, this moth, in the genus Acrolophus, family Acrolophidae, used to be placed in the family Tineidae (clothes moths and their kin). Acrolophus species are known as "grass tube moths" because the caterpillar stage of many species spin silken tubes at the base of grasses, or grass roots, to conceal themselves as they feed.

Acrolophus sp.

The genus Ethmia, very abundant in oak woodlands in the foothills here, but a rarity at my blacklight on the high plains, used to be in the family Coleophoridae. Now it is in the family Depressariidae. It can be depressing to me to try and keep up with all these changes. This specimen is probably Ethmia discostrigella, which feeds as a caterpillar on Mountain Mahogany, a woody shrub. Most Ethmia feed on plants in the Boraginaceae family.

Ethmia sp.

Here is another member of the Depressariidae family that I have not yet identified. They can be confused with tortricid leafrolling moths but for the upturned palps, mouthparts that in this case resemble horns between the antennae.

Moth, family Depressariidae

One might expect that pest species would dominate in urban settings, but that is not necessarily the case. Still, the ornamental crabapple trees in a neighbor's yard probably breed the Codling Moths, Cydia pomonella, that do appear with some frequency at my blacklight. The caterpillar stage is the "worm" in the apple.

Codling Moth

Some other pests include the Diamondback Moth, Plutella xylostella, a tiny insect (6-8 mm) that feeds as a caterpillar on pretty much everything in the mustard family, including cauliflower and cabbage. It may not be native here, its suspected region of origin being Eurasia, but it is now found in all corners of the world thanks to global commerce.

Diamondback Moth

I believe this moth is an adult Spruce Budworm, Choristoneura fumiferana, in the leafroller moth family Tortricidae. The adult moth is highly variable in color, and prone to wear and tear that further compromise identification. We can at least conclude it is likely in the "fumiferana species group," which includes several other conifer feeders, some of which are notorious pests of western forests.

Spruce Budworm moth or close relation

Another related species is the Large Aspen Tortrix, Choristoneura conflictana, of which I think this is an example. As one might guess, the caterpillar stage feeds on aspen, but also poplar, willow, and alder. The caterpillars overwinter, and the older instars roll leaves tightly around them to thwart predators and parasites.

Large Aspen Tortrix

Another conifer-feeder is the Ponderosa Pine Coneworm, Dioryctria auranticella. The caterpillar stage feed in cones, but occasionally on twigs, too.

Ponderosa Pine Coneworm moth

The Pink-fringed Dolichomia, Hypsopygia binodulalis, is named for the genus it was formerly placed in: Dolichomia. Little is known of its biology.

Pink-fringed Dolichomia

The Belted Grass-veneer moth, Euchromeus ocellea, is one of the more ornate "snout moths" in the family Crambidae, most of which are associated with grasses as caterpillars. This one may be lovely to look at, but its larva feeds on the roots of corn. It may have originated in Europe, where the species was first described.

Belted Grass-veneer

Only a couple larger moths surfaced at my place during National Moth Week, and those were both in the owlet moth genus Lacinipolia. One cannot tell the species apart just by looking. One was a mottled gray, with reflective scales on its wings; the other was a lovely green, and probably rests by day on lichen-covered tree trunks.

Owlet moths, Lacinipolia spp.

Some insects can be mistaken form moths, and chief among them are caddisflies like this one. Indeed, caddisflies, order Trichoptera, are essentially aquatic moths. Their larvae typically build cases of plant or mineral matter, or spin nets to filter microbial organisms from stream currents.

Caddisfly

Brown lacewings in the family Hemerobiidae, order Neuroptera, also resemble moths at first glance. Their larvae are voracious predators of aphids and other small insect pests, so their appearance is always welcome.

Brown lacewing

When you begin looking at the smaller moths, you may be fooled by leafhoppers like Norvellina pullata that can be as colorful as moths. Leafhoppers are true bugs that have piercing-sucking mouthparts they use to tap plant sap.

Leafhopper, Norvellina pullata

Oh, look, here is an actual moth, about the same size, if not a bit smaller, probably in the genus Phyllonorycter, family Gracillariidae (Leaf blotch miner moths).

Unidentified micro-moth, maybe a leaf blotch miner moth

Many other insects come to lights at night, and the most obvious are probably beetles. Predatory species like the Punctured Tiger Beetle, Cicindela punctulata, normally a swift, day-active hunter of other insects, and various ground beetles are common at lights.

Punctured Tiger Beetle
Ground beetle, tribe Harpalini
Ground beetle, maybe Bembidion sp.

A real surprise on July 24 was the appearance of a Pole Borer, Neandra brunnea. This insect is in the longhorned beetle family Cerambycidae, but it is anything but typical for that group. The antennae are short and bead-like, the jaws suggestive of a ground beetle or small stag beetle. The larval stage bores in decaying wood, including poles and posts in contact with moist soil.

Pole Borer, Neandra brunnea

Click beetles in the family Elateridae are also very commonly drawn to lights at night. They are bullet-shaped, and often covered in short, dense hairs that make them slick. Try grabbing one and it will likely slip right through your fingers. If you are successful, you may be startled by a jarring "click" as the beetle snaps a spine into a groove on its chest. This can free the beetle from many small predators, and catapult it away from danger, too.

Click beetle, family Elateridae

Tinier beetles include shining flower beetles, family Phalacridae; deathwatch beetles, family Ptinidae; and ant-like flower beetles, family Anthicidae.

Shining flower beetle, family Phalacridae
Deathwatch beetle, family Ptinidae
Antlike flower beetle, Notoxus sp.

True bugs, besides leafhoppers, are always a fixture at lights at night, too. Plant bugs in the family Miridae are diverse if not abundant. Phoytocoris spp. are usually gray or brown, and mostly plant-feeders. They will occasionally prey on smaller insects, though. Orthotylus spp, Ceratocapsus spp, and the distinctive Reuteroscopus ornatus, are typical visitors to my blacklight, along with Lygus spp (or a lookalike genus).

Mirid plant bug, Phytocoris sp.
Mirid plant bug, probably Orthotylus sp.
Mirid plant bug, maybe Ceratocapsus sp.
Mirid plant bug, Reuteroscopus ornatus
Mirid plant bug, possibly Lygus sp.

The large dirt-colored seed bug Balboa ampliata visited on July 24. It may be a more common species than I first suspected, as I have found it in other prairie and foothill habitats around Colorado Springs. As the name suggests, these bugs feed on plant seeds.

Seed bug, Balboa ampliata

One cannot escape the presence of true flies at any time of day or night, and many species are attracted to lights. Crane flies in particular are almost guaranteed visitors.

Crane fly, family Limoniidae

Tiny gall midges in the family Cecidomyiidae are also common. Larvae of many species live in galls on plants.

Gall midge, Lasioptera sp.

Biting midges in the family Ceratopogonidae, the "no-see-ums," are also present. Fortunately, most members of this family feed on the blood of other insects, not people or pets.

Biting midge ("no-see-um"), family Ceratopogonidae

Non-biting midges in the family Chironomidae can be overwhelmingly abundant, but they do not bite. They look enough like mosquitoes to cause needless consternation, but neither gender usually feeds on anything. They live their very short adult lives by using the fat reserves they accumulated in the aquatic larva stage.

Non-biting midges, family Chironomidae, various species

I am rarely plagued by mosquitoes here on the Front Range, but one female did bite me on the arm on July 24. A male, the gender that does not bite, showed up on July 30.

Female mosquito, Ochlerotatus dorsalis
Unidentified male mosquito

Maybe some of the predators and scavengers, like spiders, earwigs (omnivores), and harvestmen ("daddy long-legs," related to spiders in the class Arachnida) are keeping the mosquitoes and other nuisance insects at bay around our townhouse. We can only hope.

Longlegged sac spider, Cheiracanthium sp.
European Earwig female
Harvestman, arachnid order Opiliones

5 comments:

  1. Hi! I'm in Carbondale, CO and had a question on what I assume is a Ground Beetle (Harpalini) like pictured in your post. Earlier this summer, late at night, my dog was following one around our driveway. Several times he jumped back with a doggy "wow that stinks" face. Do these beetles emit a deterrent scent? And thanks for the means to id critters - the "big ass spider" on my porch is now a Cat Faced Spider. Pretty sure I will still recoil with an eek when the ground beetles scuttle out when I'm pulling weeds. Baby steps!

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    1. Pretty sure the beetle your dog was following was a different one: Eleodes spp. in the family Tenebrionidae can emit really obnoxious chemical defenses.

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  2. The harvestman is almost certainly Phalangium opilio. The diamond-shaped 'saddle' marking is characteristic of members of the family Phalangiidae, and P. opilio seems to be the only phalangiid known from Colorado.

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  3. Very extensive! I would have never known that the pole borer was a Cerambycid.I would have been chasing after an ID within the Darkling beetles or Bess beetles, most likely.

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