When most people think about moths,
it’s the pest species they imagine, like the caterpillars of gypsy moths and
winter moths that have defoliated area trees in recent years. But those
invasive species are hardly representative of the immense diversity of native
moths that inhabit the fields and forests of Rhode Island. An event last week
in Kingston demonstrated exactly that.
Dubbed the Moth Mingle, the annual public
program hosted by the Rhode Island Natural History Survey brought a small group
of moth aficionados, as well as the merely curious, to URI’s East Farm for a
late-night spectacle of creatures great and small that inspired wonder and
amazement.
According to David Gregg, director
of the Natural History Survey and the host for the evening, the Ocean State is
home to about 1,000 species of moths, and they play an important role in the
ecosystem as pollinators and as food for birds and other animals.
“When you see a lot of species
diversity like that, it’s reflecting a lot of complexity in our ecology,” Gregg
said. “So if you want to monitor the health of the environment, you should
direct
your attention at groups with a lot of biodiversity because it will
capture a finer grain picture.
Checking out the bait trap at the Moth Mingle (Photo by Renay McLeish) |
“Moths are also declining in number –
we know that from monitoring events like this one – and we don’t know why,” he
added. “So it’s something we need to pay attention to.”
Most moths only fly after dark, some
for only a few hours well after midnight, so the action at the Moth Mingle
didn’t really get started until complete darkness had set in. By then, several simple
strategies were in use to attract moths.
A large white sheet hanging vertically in a field
was illuminated with a light bulb. Two other bulbs – an incandescent and a
compact fluorescent – illuminated opposite sides of a piece of white cardboard
in an experiment to determine which type of bulb attracts the most moths. In
the nearby woods, a bucket trap with a black light was deployed to capture
whatever flying insects were nearby, and a bait made from overripe fruit, brown
sugar and red wine was smeared on several tree trunks to attract hungry moths
in search of a meal.
Throughout the evening, the headlamp-wearing
participants wandered back and forth from sheet to bucket to experiment to
bait-smeared trees to observe the moths, try to identify them, and learn what they
could about each species.
Alex Baranowski, a recent University of Rhode
Island graduate who describes himself as “an insect person,” has been
interested in moths since childhood when he collected and reared moth
caterpillars at his home in Bristol, Conn. He was one of the most knowledgeable
participants at the Moth Mingle, happily identifying moths and discussing their
natural history.
“I’m not sure why I’m so into moths,” he said.
“I’m just fascinated by them. They’re this large successful group of insects
that occupies just about every role in the ecosystem possible. Some eat plants,
some are predatory, some feed on decomposing insect material, some are
parasites, and some are adapted to eating food and grain that people have
stored.”
By 9:30, moth activity had begun to pick up. A
tiny black-and-white patterned moth called a Hebrew clung to the bucket trap as
several tan-colored grapevine loopers fluttered around it.
“There are two kinds of grapevine loopers, but
only they can tell them apart,” Gregg said. “Their coloration tells you that
moths are bird food – they’re trying very hard to convince you that they’re
just a leaf.”
At the sheet, a dozen varieties of moths perched
beside tiny beetles, stink bugs, grasshoppers, caddisflies and other insects
that had been attracted to the light. A slug moth the size of a pencil eraser
was dressed in pink and pale green with furry legs. A few inches away was a
skiff moth in shades of chocolate and chestnut. A moth with a checkerboard
pattern inspired a bit of debate over its identity, while a rice-sized orange
and white moth was found to be a leaf miner.
Cindy Sabato of Wakefield attended the Moth Mingle
simply out of curiosity. She said it was a way to learn more about the insects
that were attracted to her porch light.
“As humans, I think we tend to be less afraid of
what we understand, and I love facing and becoming friends with things that
make me uncomfortable,” she said as she pointed out a moth she thought looked
like lace. “The experience was great. I was fascinated by the many types and
shapes and sizes of moths.”
Later in the evening, moth numbers and diversity
continued to increase at the sheet, but the two-bulb experiment wasn’t
attracting many moths at all, perhaps because its location was in a breezy area
that may have discouraged moths to fly. The bait sites also had few moths,
though that was expected.
“Only half of moth species eat as adults,”
Baranowski informed the group. The others only eat as caterpillars. In
addition, many of those that would be attracted to the smell of the bait don’t usually
become active until closer to 2 in the morning, he added.
Back at the sheet, Gregg asked the group, “Who
wants to see a moth’s eyes glow?” As expected, all of the participants did.
After everyone got their turn to see the tiny reflection of a moth’s eyes in
his flashlight, Gregg said, “humans are simultaneously curious and frightened
of things in the dark. So we turn on a light and we find that they’re cool.”
At the
event’s conclusion, Sabato was pleased to have learned so much about moths. “I
most certainly walked back to my car feeling less afraid of being hit up by
flying insects in the night than when I went in,” she said. “So mission
accomplished.”