Butterflies, moths and caterpillars

Wolly Bear Caterpillar

This is the time of year when we find caterpillars crawling about on plants and trees.  A caterpillar is the larval form of insects in the order of Lepidoptera, commonly known as butterflies and moths.  One common caterpillar, the Wooly Bear found on the ground or in dead leaf litter, will curl up when touched.  It’s presence and width of the brown band is often tied with folklore in predicting the severity of the coming winter months.

Isabella Tiger Moth

This moth overwinters in the larval stage and pupates in the spring to become the Isabella Tiger Moth.

www.Butterfliesandmoths.org has an online identification guide that asks four questions and can be simplified and narrowed to the local region.  To find the Wooly Bear, I choose Black Body Color, Banded, with Dense Hair,   Click here for the guide and try it yourself……

Two of the pictures below were submitted by Siri in Stonginton & the picture with the caterpillar on my finger was taken in Acton.  If you can identify these, please send along an email to let us know what they are!

The families of butterflies are only a fraction of that of moths however together they are certainly the most beautiful group of insects that give rise to our curiosity.

Robert M Pyle

This picture was taken in July when I attended Wildbranch Nature Writing Workshop sponored by Orion Magazine.  I had the pleasure of working with Robert M. Pyle, a foremost Lepidoptera expert and author of National Audubon Society’s field guide to North American Butterflies among numerous other books and publications including Chasing Monarchs: Migrating with the Butterflies of Passage (2001) and Mariposa Road: The First Butterfly Big Year (2010).  In 1971 Bob started The Xerces Society for Invertebrate Conservation.  Our group had stepped out of the lecture room for a short explore on Sterling Farm with Bob as our guide.  What a privilege!

The order of Lepidoptera has 4 stages of development; egg, larva (caterpillar), pupa (cocoon or chrysalis) and adult.  All adults have 2 pairs of wings that are covered in powdery scales and tube-like mouthparts used for sucking that form a tight coil when not in use.

White Admiral

The difference between butterflies and moths is most easily seen in the antennae.  Butterflies have thin antennae that ends in nobs while moth antennae do not and are often times feathery.  Also, butterflies usually rest with their wings held together such as this White Admiral submitted by Pam Wells.  Moths on the other hand, rest with their wings held open.

Although this is not always true for all species, it is a quick way to generally know if you are looking at a butterfly or a moth.

The larva are often highly specialized in their need for habitat such as the Monarch or Milkweed Butterfly so named because the larva only feed on the milkweed plant.  There has been recent concern over the decline of this species that was reported in the Weekly Notes, September 1, 2013. 

The State of Maine lists 8 species of Lepidoptera on the Threatened and Endangered Species List.

While some species in this order are at risk because of habitat loss, others are considered pests because of their destruction to plants and trees.  An example of this is the Winter and Browntail Moths that are listed on the State of Maine Invasive Threats list.

At Frost Pond Camps in T3R11, a light-trap is maintained from mid-June to mid-July each year to collect moths.  Each morning the trap is emptied and the moths that are collected placed in a box to be sent to the Entomology Department at the State Forestry office for identification and recording.  This location is an important collection site since it serves a large portion of the commercial working forest just west of Baxter State Park.  Through annual record keeping of the species of moths collected, forest managers are able to make population predictions and monitor potential outbreaks of destructive pests such as the Spruce Budworm, the larval form of the Tortricid Moth which remains a real concern in the north woods.

Fred Gralenski posed a question from the Weekly Notes on August 4, 2013,  He asked, “I never noticed that the front legs were not used, and I wonder how many species have that characteristic and why.”  Fred researched his own question and his answer is below.

Milkweed or Monarch Butterfly

The butterflies with ‘4’  legs are the Nymphalidae, or brush-footed butterflies.  These include the admirals, fritillaries, checkerspots, crescentspots, anglewings, leafwings, ladies, tortoiseshells and longwings.  A subgroup, Danaidae, also have reduced forelegs and this includes the Monarch.  Notice the picture of the monarch.  Still don’t know why this is.  Maybe they just don’t need forelegs anymore.

Big Poplar Sphinx moth

Fred also submitted photos of some moths found in Calais at the ‘Relay for Life’ on the evening of June 15th.  He says, “I captured them and photographed them on the 16th before letting them go.  A couple of good ones got away before I took their pics.”