Sunday, August 21, 2011

Summer butterflies, moths and caterpillars

With the heat of summer come butterflies, moths and their caterpillars. They are found anywhere, from meadows to woods, roadsides and city gardens. Some are large and exotic like the Tiger Swallowtail, some plentiful and small like many Sulphurs and Whites.

Tiger Swallowtail on Chives
Most of you will be familiar with the orange and black Monarch butterfly. Several Monarchs have laid their eggs on Common Milkweed growing in our yard.

Monarch Butterfly

Pair of Monarchs mating

Milkweed is the host plant for the Monarch butterfly caterpillar.The caterpillars live and feed off the host plant until they are large enough to move on to a nearby shrub or plant to pupate.

Monarch buttercly caterpillar on Common Milkweed

Monarch early stage pupae

Monarch butterfly late stage pupae

These last fresh summer Monarchs to emerge will be the ones to migrate en masse on those gossamer wings all the way to the mountains of central Mexico where they will overwinter in an old growth forest. Those who survive winter in Mexico will start the journey north stopping to reproduce another generation along the way before they die. The offspring will carry on northwards stopping along the way to reproduce then die. It is the later generations of butterflies who finally reach us to complete the cycle. An amazing migration!

 I dare not pull out the precious Milkweed that has sprung up amongst the lilies and grasses in the garden. It is threatened by herbicide use, habitat loss and invasive species such as Dog-strangling vine. Milkweed flowers are one of my favorite summer wildflowers; the soft pink globular flower heads emit a heady sweet aroma that scents the air all around.  A small patch grows near our bedroom window and the delightful intoxicating fragrance permeates the room during warm summer evenings. No commercial air freshener can match that! The sweet nectar attracts a host of other insects too.  This late in the season, the flowers have faded and great big green seedpods have developed ready to burst out thousands of fluffy seeds to be borne on the breeze and hopefully settle elsewhere.

Another spectacular summer butterfly is the Black Swallowtail Papilio polyxenes, a large black butterfly with tail-like projections at the base of the wings with white, orange and blue markings. For a photo and more info:
 The host plants for the caterpillars are in the carrot family which includes Queen Anne’s Lace, Dill and Parsley. I am currently watching 2 Swallowtail caterpillars developing on my parsley plant. They started off as little black caterpillars with a white band across the middle, looking a bit like a bird dropping, this is the first instar (phase).

Within 2-3 days of munching on the plants the caterpillars shed their too-tight skin. With each shedding, the caterpillar is larger, colours more vivid and the pattern is more pronounced until it reaches in the final instar. Soon it will leave the parsley to find a suitable spot to pupate.
Black Swallowtail caterpillar second instar

Black swallowtail third instar

Polyphemous moth caterpillar

Yesterday a big green fat caterpillar came wandering by while I was sitting in a favorite chair on the front porch (having an organic wild untidy garden has its benefits). After snapping a few photos, I did a quick computer search to identify it and found it to be the caterpillar of a large silk moth: Polyphemous Moth Antheraea polyphemus.
The hosts for this species are trees such as Oak, Maple and Birch and we have plenty of these in our yard. For a photo and more information about this beautiful moth check out this site:
Other recent caterpillar finds in the garden:

Toadflax Brocade Moth Calophasia lunula  caterpillar
 Several caterpillars were feeding on a large Toadflax plant. They are a species imported from Europe decades ago for control of this invasive plant. for a photo of the moth.


Pandorus Sphinx moth caterpillar

Pandorus Sphinx Moth Euphorma pandorus caterpillar
Final instar, found feeding on Virginia Creeper. I’ve also found one feeding on Wild Grapevine which we have in abundance. For photo of moth check this link

a tangle of flowers

When reading about all these caterpillars, I found that many are considered pests. I suppose if you had enough of them they could wreak havoc on host plants but I have never found this to be the case. Perhaps the many birds and bats and other natural predators found in my wild tangled organic garden help keep these in check. I see Robins making trip after trip to the nest with beaks full of caterpillars, worms and other insects; Baltimore Orioles, Warbling and Red-eyed Vireos pick insects and tiny caterpillars off leaves; Eastern Bluebirds, Phoebes, Pewees, Eastern Kingbirds flycatch from strategic perches and Big Brown Bats swoop through the yard at nightfall. They are surely helping to keep everything in balance….

1 comment:

  1. Did you ever find out what my caterpillar was? I know it was a moth of some sort since it pupated in the jar I put it in. I took a couple of pics of the moth through the jars before I released it. The pics are blurry but I could send them on...