Common Name: American Dagger moth, Fishers Island, NY, June 2017.
Scientific Name: Acronicta Americana
Season: One generation in the Northeast. Adults in early summer, with caterpillars from July into the fall.
Food: Ash, elm, hickory, maple oak, poplar, willow.
Ecology: A forest moth, American dagger caterpillars can be found feeding on many deciduous trees. The caterpillars are covered in yellow tufts of hair that can cause irritation to the skin in some people.
Adam Mitchell Photo
Common name: Angulose prominent, Fishers island NY, June 2017.
Scientific name: Peridea angulosa
Season: Two generations in the Northeast. Adults, late spring into June, and again in late summer. Caterpillars through summer and late into fall. Caterpillars overwinter as pupae and seek out sites to pupate when the leaves fall.
Food: Exclusively, species of oak.
Ecology: Caterpillars of the angulose prominent are specialist feeders, meaning they can only feed on one or two species of plants to grow and develop. When disturbed, the caterpillars coil up like snakes, although they are completely harmless.
Adam Mitchell Photo
Common name: Banded tussock moth, Fishers Island NY, June 2017
Scientific name: Halysidota tessellaris
Season: One generation in the Northeast, although caterpillars and adults are active throughout the summer and fall.
Food: You can find these guys in the summer on just about any tree or shrub in the forest.
Ecology: The species name for the moth (tessellaris) stands for “little square stone” in Latin (rough), which refers to the blocky pattern on the moth’s wing. As a caterpillar, it is covered in tufts of hair that makes it unattractive as a food item for birds (although the birds don’t mind eating the adults!). Picture of caterpillar is from Newark DE, August 2014.
Common name: Banded tussock moth, Fishers Island NY, June 2017
Scientific name: Halysidota tessellaris
Season: One generation in the Northeast, although caterpillars and adults are active throughout the summer and fall.
Food: You can find these guys in the summer on just about any tree or shrub in the forest.
Ecology: The species name for the moth (tessellaris) stands for “little square stone” in Latin (rough), which refers to the blocky pattern on the moth’s wing. As a caterpillar, it is covered in tufts of hair that makes it unattractive as a food item for birds (although the birds don’t mind eating the adults!). Picture of caterpillar is from Newark DE, August 2014.
Common name: Black-dotted ruddy, Fishers Island, NY, June 2017.
Scientific name: Ilecta intractata
Food: As caterpillars, black-dotted ruddy moths are specialist feeders, meaning they can feed on only one or two kinds of plants in order to grow and develop. Black-dotted ruddy moths feed on American holly trees, and can be a common inchworm in suburban environments where holly trees are planted.
Ecology: This species is attracted to artificial lighting, which can increase predation risk, disrupt behaviors such as feeding, flight and reproduction, and interfere with dispersal among habitat patches.
Common name: Black zale, Fishers Island NY, June 2017
Scientific name: Zale undularis
Season: Adults start flying in the Northeast in late spring and into September. Caterpillars are common by June.
Food: The caterpillars feed exclusively on locust trees.
Ecology: This dark-colored moth is able to camouflage itself against the bark of trees, whereas its caterpillars feed on the underside of leaves to hide from predators. The caterpillars are incredibly muscular, and when alarmed, will launch themselves from leaves to avoid capture.
Common name: Blue Dasher, Fishers Island, NY, July 2017
Scientific name: Pachydiplax longipennis
Not a moth, but too beautiful to omit. The blue dasher is one of the more common dragonflies in the eastern U.S. and one of the most striking. Like many dragonflies, this species is sexually dimorphic, meaning that the appearance of the individual depends on its gender. Only males develop bright blue abdomens, whereas females have an orange-and-black pattern instead. This is a fully mature male.
When adults perch, they tend to raise their abdomens in the air in what is known as the “obelisk” position. This is believed to be an effective way to minimize heat by allowing more wind to pass over the abdomen.
Common name: Common spring moth, Fishers Island NY, June 2017
Scientific name: Heliomata cycladata
Season: March-July
Food: Black locust and honey locust.
Ecology: As the name implies, these moths are common to see during the spring and into July through the Mid-Atlantic. Although small, they are quite beautiful.
Common name: Curved-toothed geometer
Scientific name: Eutrapela clemataria
Food: Larvae feed on leaves of ash, basswood, birch, elm, fir, maple, poplar, willow and other trees.
Ecology: These geometers live in deciduous and mixed woodlands. Their scientific name derives from the Ancient Greek “measure” “the earth” in reference to the way their larvae, or inchworms, appear to “measure the earth” as they move along in a looping fashion. The geometer has two generations a year and is part of a very large family of around 23,000 species of moths.
Lucinda Herrick Photo, July 2018
Monarch butterfly caterpillar and aphids, Fishers Island NY, August 2015
Scientific names: Danaus plexippus and Aphis nerri
Here’s a bit of hidden moth science, provided by entomologist Adam Mitchell, PhD:
Like animals, plants have an “immune system” and have a series of finely-tuned responses to specific stressors in their environment. When a leaf is chewed, signals are sent to the plant to create defenses that prevent further feeding. When, for example, a caterpillar chews on a leaf, the production of a hormone called jasmonic acid (JA) signals that kind of response. In contrast, when an insect feeds on the vascular (xylem-phloem) tissue of a plant, such as an aphid, a different signal is sent, and a different hormone is produced. This one is called salicylic acid (SA).
Generally, these different signals allow plants to focus specific defenses against specific threats. However, the production of one signal can sometimes prevent another. If a plant is already producing salicylic acid, it struggles to produce jasmonic acid. That is, if aphids are already feeding on a plant when a caterpillar begins to chew on the leaves, the plant cannot raise its defenses as effectively against the caterpillar as it usually would, because it’s already producing defenses to defend against the aphid.