Disappearing Denizens of the Night
Moths are often maligned as the pesky flyers around the
porch light or, worse, closet and pantry marauders. True,
most moths do fly at night or hide themselves away in
dark places. However, our focus here is on a different
group of moths altogether. Unlike butterflies and other
moths, these moths won’t flit from flower to flower
because they do not eat — at least not in their short adult
life. These interesting flyers have no mouthparts as adults
and are all about reproduction.
What are these creatures of the night that have a
wingspan the breadth of a man’s hand, with colors and
markings that rival those of many butterflies? What are
these neighbors of the night that demand no nourishment,
no sustenance? They are wild silk moths!
Gentle Giants
If you have been fortunate enough to see one or more of
these lovely insects, it is not a sight you will soon forget.
Due to their large size, some can be confused with our
indigenous small brown bat. The most common natives to
New England are the luna, polyphemus, promethea, io
and cecropia moths. They are all of the family
Saturniidae, which includes the largest in the world, the
Atlas moth, hailing from Asia with a wingspan of up to one
foot! The cecropia is the largest moth in North America —
sometimes attaining a wingspan exceeding six inches. It is
also well known in its larval, or caterpillar, stage due to
its enormous size and colorful knobs (or tubercles) that
adorn its blue-green body.
I am in my eleventh season of spending intimate time with
these extraordinary creatures. I am there as they emerge
from their wintered-over cocoons. I place my female
moths out to attract wild males for mating, collect a
handful of the hundreds of eggs each will produce, and
raise the tiny caterpillars right from the egg. They feed
for 5-8 weeks all summer — mostly on a selection of trees
and shrubs in various habitats — as they grow to two to
over four inches, are smooth to spiny, or are decorated
with what seems like bells and whistles! I then watch in
awe as they magically spin their silken robes for a long
winter slumber once again. Of the 100-300 eggs these creatures can deposit, barely
2% will make it to the adult moth. They struggle with
both natural and human-induced causes of decline. As
caterpillars, they are prey to parasitoid wasps and flies
and can succumb to a variety of diseases — bacterial,
fungal and viral. Some are meals for
birds, and in their pupal stage they are
often found in fall, winter or spring by
hungry mammals. Habitat degradation
and pesticides also take a toll.
Nature’s checks and balances have somehow
managed to keep plenty of these winged wonders
among us. But there is now a new and serious threat. It
is a tachnid fly, which was introduced in the early 1900s
to control gypsy moths. The fly now attacks hundreds of
hosts in three different insect orders — including
Lepidoptera. Our native Saturniid caterpillars' size and
feeding habits make them ideal marks for this multi-
generational fly, which inserts its larvae directly into its
host. Research is being done, but alas, few have
adequate funding and resources.
There is not much we can do about the natural and non-
native impacts, but individually each of us can take action
to help these insects’ overall survival through their stages.
- Bonnie J. Caruthers is a naturalist, freelance nature photographer, and
writer living in Walpole, NH. She frequently speaks on Backyard Pollina-
tor Conservation, Wild Silk Moths and Native & Invasive Plants. For some
up-close moth encounters, visit her photo exhibit at Strand Style Studio,
upstairs at 55 Village Square in Bellows Falls, VT, through September. Or
come to her program at the Museum on Friday, July 10 at 10:00 AM.
How You Can Help Gentle Giants ~
Tips from Bonnie Caruthers
• While some moths winter over as eggs on
stems, the luna, polyphemus and io moths spin
their cocoons that range from tight and hard to
papery and then fall to the ground. These may
end up in the compost pile or garbage when
you rake and toss. If you can resist having a
spotless yard, you may have more night
flyers the following summer. Also you may
not be destroying the overwintering
chrysalises of butterfly pollinators, such as
spicebush swallowtails.
• Some moths burrow into the ground and remain
as "naked" pupae all winter. If you unearth one
while digging, gently replace it.
• Avoid the urge to seek and destroy every
crawly that nibbles on a leaf! Often the bigger
it is, the more it may seem creepy; yet it may
just be one of our Gentle Giants.
• Minimize or stop your use of pesticides.
Polyphemus moth. Copyright © Bonnie J. Caruthers
Cecropia Caterpillar. Copyright © Bonnie J. Caruthers
COLLAPSE of the COLONIES: Can Vermont’s Bees Remain Strong and Independent?
…It’s easy to ignore the myriad organisms on which we depend. Most are small, unnoticeable creatures that we label as pests. But as we support local farmers and seek to sustain ourselves from our own gardens, we must remember that our endeavors would not be possible without pollinators…
Pollination is the essential reproductive strategy of the world’s more than 240,000 flowering plants – at least three-quarters rely on an animal to conduct the necessary transfer of pollen. The best-known pollinator is the honey bee (Apis melifera), which effectively pollinates more than 100 commercially-grown crops in North America….But the honey bee is not alone, and is not even native to this continent. For the millennia prior to the bee’s introduction, pollination was performed by a multitude of native insects, including solitary bees, wasps, flies, beetles, moths, butterflies, and thrips, as well as birds and a few mammals.
Honey bees were first introduced to North America at the Virginia colony in the early 1600s. Beekeeping moved slowly north, arriving in Vermont around 1720. At first, bees were kept in makeshift hives and allowed to gather and hoard their honey supply. In the fall, keepers would kill the bees with a sulfur gas and destroy the hive to collect the honey, hoping they would find wild swarms and restock in the spring.
In 1862, modern apiculture was born when L.L. Langstroth developed the movable-frame, top-bar hive. By permitting access to the hive’s interior, honey could be collected without destroying the occupants. Beekeeping flourished, and by 1900 Vermont and Maine led New England in honey production.
In 1947, the U.S. Department of Agriculture estimated there were 5.9 million colonies in the United States, but by 2005 that number had dropped to 2.4 million. Much of the decline has been attributed to the Varroa mite, a tiny parasite that lays its eggs in comb cells so its young can feed on the developing bee larvae. An infected hive will fail within one or two years.
Colony Collapse Disorder (CCD) gained media coverage in 2006, when some large beekeeping operations in the U.S. reported losses as high as 80% of their hives. Many causes have been suggested for CCD, including…genetically-modified crops, malnutrition, and use of synthetic pesticides….Experts are now saying that CCD is more likely caused by a combination of factors that stress and weaken a colony to the point of collapse. Among these stressors are malnutrition, long-distance transport of hives, Varroa mites, viral infections, other diseases (such as American Foul Brood), and the use of chemicals to control these pathogens.
According to Steve Parise, the VT State Apiculturist, CCD has not yet been reported in Vermont. “The decline of honey bees,” he reports, “has not been as evident here, and the number of beekeepers [about 1,600] and annual production of honey [500,000 pounds] has remained fairly constant the past few years.” This brighter picture speaks to good hive husbandry practiced by many VT beekeepers, most of whom keep fewer than five hives. Also, many have adopted an organic approach that, in Ross Conrad’s view, “reduces stress on the bees, and is why organic beekeepers seem to be faring better during these times of such devastating losses elsewhere.”
Still, Vermont’s beekeepers must remain diligent in protecting themselves from losses caused by Varroa mites...many keepers are breeding their own replacement stock with bees resistant to mite and viral problems…
Although honey bees are faring relatively well in Vermont, there is growing concern about wild pollinators. There are 49 species of bumble bees in the United States (18 in Vermont), and some have become commercially important because they function as “buzz-pollinators” – a bee that literally vibrates pollen grains from the anthers of certain flowers, including cranberry, blueberry, tomato, and cucumber. As an alternative to honey bees (which do not buzz-pollinate), several bumble bees are imported and managed for crop production, most notably greenhouse-cultivated tomatoes. However, imported bumble bees often escape to the wild, where they can potentially infect native populations with pathogens that arise in confined colonies. As a result, several species of native bumble bees have suffered significant declines.
In 2007, the National Academy of Sciences warned that “pollinator decline is one form of global change that has a credible potential to alter the shape and structure of the terrestrial world.” Landowners throughout Vermont can improve habitat for native pollinators by doing three basic things.
First, provide a diversity and abundance of pollen and nectar sources by planting flowers that bloom at different times during the growing season…Native or naturalized plants are best, since they have adapted to local growing conditions and native pollinators have evolved along with them.
Second, provide quality nesting sites. Because many native bees nest in soil, provide patches of bare ground adjacent to crop fields and gardens…. For guidelines for constructing nest boxes (and selecting beneficial plants) see the Xerces Society for Invertebrate Conservation website, www.xerces.org.
Third, cut back or eliminate the use of pesticides. If chemicals are deemed necessary, choose ones that directly target specific weeds or pests, and make sure application methods reduce drift into natural habitats and are used at night, when bees are inactive. The Natural Resource Conservation Service’s website, www.nrcs.usda.gov, offers guidance on how to improve pollinator habitat through such actions as the creation of hedgerows and wildflower meadows.
Homeowners can also learn to tolerate weeds along property edges and allow old fields to repopulate with weeds and wildflowers. Simple measures like these will help perpetuate healthy populations of beneficial insects and ensure that the pollination services they perform in Vermont will continue to enhance our local food production for years to come.
(This abridged version is from an article reprinted with permission from Vermont’s Local Banquet magazine, Saxton’s River, VT, Spring 2008, Copyright © 2008 by Rick Enser. Visit www.localbanquet.com to read the full article.
