What good is a moth anyway?
Are you someone who believes moths are drab-coloured and destroy your woolens while butterflies are far lovelier to look at? Well, we beg to differ. During our time at the lake we see many beautiful moths, some of which we have even initially mistaken for butterflies. Take for example the grape leaffolder moth which we saw in June. We went to our butterfly books first, thinking we had a new butterfly, but no, many hours of page-turning later, we found it on page 171 of Peterson’s moth book where we were able to identify it.
Sometimes it is names of moths, more than the colours, that most amuse us. Peterson lists leaf-cutters; folders; miners; rollers; and sewers, each describing to some degree or another moth behaviours. The last … the leaf-sewer should be pronounced as a synonym of seamstress. White Lake provides a home for both leafroller and leaffolder moths, probably others too which we simply have not yet seen and photographed. Below is a photo of an oblique-banded leafroller moth. We see these moths every year near the end of June. Yes, they feed on our oak and other trees, but we are nevertheless delighted by their shape, colour and pattern.
But what good are moths anyway, beyond aesthetics? In addition to providing food for a wide variety of White Lake wildlife, moths play a major role in the diet of bats and many of our garden birds. Even chipmunks feed on the pupa within a moth cocoon as an important part of their protein intake. The following photograph, taken in June, is of our very own carnivorous chippy eating an eastern tent caterpillar moth pupa after tearing through the silky cocoon.
Like butterflies, moths are also important pollinators. Here is a photograph taken early in July of a Virginia ctenucha moth on Queen Anne’s lace fulfilling this important role.
One source told us there are some 250,000 species of moth worldwide; another indicated that there are 11,000 in North America. We can tell you that at least 50 species fly at Three Mile Bay because that is the number we have photographed and identified (with help) since 2006. Mind, we have a number of unidentified photographs too. In any event, in addition to the grape leaffolder moth, the variable fan-foot moth is a new one to us this year, raising our count to +50 species. In this photo, a goldenrod crab spider has a variable fan-foot moth firmly held in preparation for supper. This picture offers a bit of a finding waldo challenge, but if you squint a little and cock your head sideways, you can see the white spider in the foreground firmly holding the moth by the tip of its abdomen.
Some moths are diurnal, flying during the day; while others are nocturnal, flying during the night. For us seeing the nocturnal ones is a challenge, but occasionally, a nocturnal moth will be resting (or dying) at the roadside when we walk by in the early morning. Last year, we saw a rather beaten up cecropia moth but the photo was not MillstoneNews-worthy; however, this year a reader contacted us to ask for advice identifying a moth that sat down on his porch rail … and died. He offered us the opportunity to photograph it and, as you can see in the following photograph, it was an excellent specimen of a cecropia moth. The large and beautiful cecropia moth usually generates a lot of excitement when people are lucky enough to see one. They are members of the giant silkworm moth family which, years ago, entrepreneurs thought could be harnessed for silk thread manufacturing in North America. Unfortunately, the cecropia moth’s silk threads were not suitable. Sadly, the numbers of this moth are in decline.
While some moths can be very damaging and rather drab or dull to look at, others can be beautiful or even beneficial. So the next time you come across a moth you may want to look more closely and try to figure out its role in our natural environment.
As usual, we had a lot of help writing this article from our ‘friends’ on the Insects and Arthropods Facebook page for identification. We also used Peterson’s Field Guide Moths of Northeastern North America; and Acorn’s Bugs of Ontario.