Flora and fauna of the Athens County area, and occasionally habitats outside Ohio. Subject matter will consist of both interpretive material and taxonomic issues in plant and animal identification.

Wednesday, July 13, 2011

Noctuid Moths & Tiger Moths

Hypena bijugalis, Dimorphic Bomolocha

Hypena madefactalis, Gray-edged Bomolocha

Hypena palparia, the Mottled Bomolocha

"Ya, okay, umm these are just a bunch of dull brown moths". Oh, then we must be talking about the Noctuidae, the Owlet Moths. This is the group responsible for such comments.  Butterflies and Moths are the second largest group of insects in the world. The largest family in the order are the Noctuids. Some of our worst agricultural pests are in this group, and known as Cutworms. If you work with the family, you'll find out not all of them are plain.

An example of a more highly patterned species is Paectes oculatrix, the Eyed Paectes.

Another genus in the family is Acronicta. This is Acronicta lepusculina, the Cottonwood Dagger Moth. The larvae feed on Cottonwood, Aspen, and Birch. During the day the adults remain hidden on the light colored bark of the very same trees.

Like Prominent moths, some Noctuids break up their outline with tufts of hair. This is Allagrapha aerea, the Unspotted Looper. In the right light, the colors reflect an iridescent coppery bronze.

One of those colorful members of the family is the Beautiful Wood-Nymph, Eudryas grata. Not only is the color pattern nice, but the legs are covered in oversized bundles of fur. Notice the smooth green line bordering the red edge. If that line was wavy, this would be the similar species, the Pearly Wood-Nymph.

Among many moth collectors I've known, the Underwings, or Catocala are their favorite group. Most of the Underwings appear in late summer. Their upper wings have patterns that match tree bark. They could be literally right in front of your nose, and you'll miss them. This is Catocala serena.

If startled, they will flash their bright hind wings to a predator, confusing them just long enough to make an escape. Underwing Moths, like Sphinx Moths do feed as adults. They love nectar, but will seek out wounds in trees where the sap is running. Spreading a combination of fermented fruit and stale beer on tree trunks makes quite the concoction for "baiting" these moths in.

Catocala moths are hard to sneak up on. They have large eardrums on their abdomen of all places. One snap of a twig with your foot, and they're gone. This is why you set out bait for them. After drinking so much liquid, they just fall to the ground and flop around. Either that or they're just plain drunk! This one is Catocala nebulosa, the Clouded Underwing.

I stick this picture in for one reason only. If you plan to do insects to the species level, it's almost A MUST to create a series of specimens to compare with. The Underwings, like Skipper Butterflies, and Micro Moths are so similar, misidentifications can become a problem.

Oh My! We're not in Kansas anymore Toto. No more dull looking moths. When you come across a group of highly spotted and striped moths, you are probably looking at the Arctiidae, the Tiger Moth family. The first is the St. Lawrence Tiger of Canada, followed by two southern species, the Bella Moth and the Polka-dotted Oleander Moth of Florida.

One of the larger species in our area is Grammia virgo, the Virgin Tiger Moth.

Not until it opens its wings can you see just how brightly colored this species is. Many Tiger Moths are foul tasting and openly fly during the day. They don't fear being eaten. After a predator has tried one and gotten sick, they avoid any bright patterned moths like this.

Virbia laeta, the Joyful Holomelina is another that shows that red and black serves as a warning coloration. Even at night the tiger moths have a method of predator avoidance. When bats chase after them, tigers send clicking noises back to the bat as a warning not to eat them.

The Milkweed Tiger Moth, Euchaetes egle, is another one with warning coloration. It may not have colorful patches or stripes, but those spots on the body tell us it's a Tiger Moth. What makes this moth so nasty tasting is the food plant the larvae feed on.
Here is the caterpillar of the above moth. It too has its own warning colors. They feed on Milkweeds, which contain alkaloid poisons that they themselves are immune to.

It may not be striped, but what has spots and is related to a Tiger? How about a Leopard Moth, Hypercompe scribonia. The body is a metallic blue dotted with yellow. Notice how the wings look worn at the edges. Leopard moths often hatch with incomplete scales, and it's unusual to find one in perfect condition.

The wings are metallic red, the abdomen iridescent black, and all parts of the moth are sprinkled with a sky blue powdering. This is the Spotted Oleander Moth, Empyreuma affinis. Like the Polka Dot Moth pictured earlier, it feeds on the poisonous shrub Oleander. This is a tropical species that migrated into south Florida years ago. It was restricted to the extreme southern counties, but because Oleander is such a popular landscape plant, the range of this moth is steadily spreading northward in Florida.