Sunday, September 30, 2012

Common Buckeye Butterfly

Junonia coenia, the common buckeye butterfly, is chestnut brown. The forewing has two orange bars and two bull's-eye spots; a white band surrounds the larger spot. The hindwing also has two spots; the upper one contains a purple crescent. Click to enlarge. 
Buckeye caterpillars come in various forms but usually have an orange head, a black body with white and orange side stripes, and spiky blue spines along the top. More spines grow from orange bumps along the sides. Click to enlarge. 
The buckeye is common throughout most of the United States, living year-round in the southern states. Every year when weather warms in late spring and early summer some buckeyes go north to colonize areas as far as southern Canada.  Northern populations move southward in autumn, sometimes migrating in large numbers. Adults and caterpillars overwinter in the southern parts of the range.

Buckeyes are found in fields of flowers, open ares, roadsides, gardens, and parks. I saw dozens of adults and caterpillars this weekend while walking in the Edwin B. Forsythe National Wildlife Refuge on the New Jersey coast near Atlantic City.

Sunday, September 23, 2012

Last Butterflies

Autumn again already! Here are a few pictures of the last of this year's butterflies. Click to enlarge.

And here's a poem for the first week of autumn --

September Midnight by Sara Teasdale

Lyric night of the lingering Indian Summer, 
Shadowy fields that are scentless but full of singing, 
Never a bird, but the passionless chant of insects, 
Ceaseless, insistent. 

The grasshopper's horn, and far-off, high in the maples, 
The wheel of a locust leisurely grinding the silence
Under a moon waning and worn, broken, 
Tired with summer. 

Let me remember you, voices of little insects, 
Weeds in the moonlight, fields that are tangled with asters, 
Let me remember you, soon will the winter be on us, 
Snow-hushed and heavy. 

Over my soul murmur your benediction, 
While I gaze, O fields that rest after harvest, 
As those who part look long in the eyes they lean to, 
Lest they forget them. 

Sunday, September 16, 2012

Milkweed Bugs

If you take a close look at a milkweed plant today you will probably see crowds of yellow oleander aphids on the stems. Before long a monarch butterfly will come for a drink of flower nectar. Turn over a leaf and you'll see milkweed bugs.

Milkweed bugs, Oncopeltus fasciatus, suck juices from milkweed tissues and seeds; they have piercing, sucking mouthparts that are like sharp straws. These three are warming up on a metal fence railing in a milkweed patch. The little one is an immature stage called a nymph. The other two are adults. 

Milkweed bugs are bright red for a reason; it's a warning to anyone who might be thinking about eating one. Like monarch butterflies, milkweed bugs become poisonous from eating milkweed. A bird that eats a milkweed bug and gets sick will remember the bright colors and avoid them in the future. The strategy is called aposematic coloration.

Even among  bright red bugs this one stands out. It has just molted its skin; the remnants are still attached to its tail end. Newly emerged insects are lighter-colored than usual and somewhat soft.
Milkweed bugs have seven stages: the egg, five increasingly larger immature stages called nymphs, and the adult. They don't make cocoons. Each nymphal stage looks a little different, but none of them have wings and they can't reproduce. Like other insects the milkweed bugs have exoskeletons that make them rigid on the outside. After growing as large as the skin will allow, they shed it and come out bigger. At this time of year and you will probably easily find all the nymphal stages and lots of adults on any milkweed plant. Click here to go to a site that has a nice drawing of the stages. 

The newly emerged bug will soon darken, harden, lose that bit of old skin, and then get back to the business of eating milkweed. Mmmm... milkweed! Click on the photo to enlarge.

Sunday, September 9, 2012

The Pink-spotted Ladybug

The pink-spotted ladybug, Coleomegilla maculata
Pink-spotted ladybugs are native to North America. They're common, but I don't see them very often; maybe they are good at hiding. This one was under a leaf.

They are flatter than most species of ladybugs and more elongated. They come in colors from pink to red. They have six spots on each wing cover, but two of those six are half circles mirrored on the other wing, so that when the wings close there seem to be ten spots on them. They have two black patches on the thorax (between the head and wings). Together, wing spots and thorax patches account for their other common name, the 12-spotted ladybug.

Look for them on plants where they forage for aphids, mites, and insect eggs. Unlike most ladybugs, they like to snack on pollen, and they are reported to be especially fond of dandelions.

Sunday, September 2, 2012

Happy Labor Day!

Laughing gulls, Larus atricilla, started flying south in August and they will be gone from the northeast by the end of September.  See you all next summer!