It has been a FANTASTIC year for butterflies and moths. Why? I’m not sure but there has been some speculation that the mild winter allowed more hibernators to survive. This would explain the incredible explosion of Mourning Cloak butterflies but what about the moths that winter as eggs or cocoons?
I’ve been keeping one single garage light on (compact flourescent bulb!) for the last few weeks, and I’ve managed to attract dozens of species, including my personal trifecta of giant silkworm moths in the family Saturniidae—Polyphemus Moth (Antheraea polyphemus), Luna Moth (Actias luna) and the Cecropia (Hyalophora cecropia).
All were photographed near my house and garage. In the morning I check “my catch”…the moths that have been attracted to the light overnight. I then carefully maneuver them onto a stick and move them to a more attractive setting than my garage’s T-111 siding!
The Polyphemus is just as large (6-inch wingspan) as the Cecropia, but more common in our area.”Polyphemus” refers to the one-eyed giant son of Poseidon in Greek mythology.
In southern New England there was a reported decline in giant silkworm moth populations. It was speculated that pesticides, habitat loss, increased lighting at night had all contributed to this decline. But there was little evidence for any of this…even that there was a decline. But it was discovered that a fly introduced to control the Gypsy Moth was parasitizing the caterpillars of these large silkworm moths. The fly is Compsilura concinnata. I have not seen any reports of declines in the North Woods.
Luna Moths (like all giant silkworm moths in the Saturniidae) are living batteries, running on energy stored when in the ravenous caterpillar stage. In fact, the adults have non-functional mouthparts. Adults only live about a week. Females mate, lay eggs and die. Males mate and die.
Unfortunately for me, this specimen was 12 feet up in a spruce and in harsh light. This photo was one of my “insurance shots” before I tried to clip the branch to move it into shaded light. That failed miserably (for me) as the Luna flew skyward and disappeared to the north.
It is surmised that the lifelike “eyes” on the Polyphemus’s hindwings startle potential predators giving them an extra second to escape.
The Cecropia is one of our largest North Woods moth having a 6 inch wingspan. Amazingly, males may fly more than 20 miles over several nights in search of females. The females release a pheromone that the males key in on. Populations are often thin with only a few adults per square mile, BUT, surprisingly populations can be quite dense in some suburban areas.
A good field guide will really inspire your moth study. Our Moths and Caterpillars of the North Woods by Jim Sogaard shows over 300 species of moths (and their caterpillars) including 9 species of Giant Silkworm Moths. Jim shares ID tips, Life Cycle, Range, Caterpillar foods for each species. Order it through Amazon.com.