Sunday, October 27, 2013

Praying Mantis

This is a female Carolina mantis, Stagmomantis carolina. It is one of quite a few different species of insect called "praying mantis." Carolina mantises come in green, brown, and combinations of both. Click to enlarge. 
The females of this species are easy to identify because their wings only cover three-quaters of the abdomen, like a hip-length jacket. I just saw four of these mantises in the space of two days -- all females. Was that a coincidence or are they up to something?
P.S. The brown one was photographed on a fencepost near the pond in Brooklyn Bridge Park. That's a bit north of their traditional range. But it is not unusual for them to get around on plants and by boat, car, truck, train, and other accidental transport. People also introduce them to gardens as egg cases from garden supply stores. Mantises are beneficial insects that prey on insect pests. Happy to see they have found our park!

Sunday, October 20, 2013

Gooseneck Barnacles

Gooseneck Barnacles. Click to enlarge. 
I was walking around the tip of Cape Henlopen in Lewes, Delaware last week when I came across the prettiest thing I have ever found on a beach -- a bunch of gooseneck barnacles. Barnacles are filter feeding crustaceans that attach to rocks or flotsam in the marine intertidal zone. These were attached to a floating marker that had broken its rope -- a bright blue and orange rigid plastic ball that said 29.  I expect that when the tide came back, float 29's gooseneck barnacle community went back out to sea.

As surprising as it now sounds, in ancient times these barnacles were thought to be the immature stage of a bird called the barnacle goose (Branta leucopsis). The shell and stalk kind of resemble the head and neck of a white-faced goose, right? Barnacle geese migrate to Britain and Ireland to overwinter there, but they nest elsewhere. Once upon a time, finding no nests, eggs, or chicks, people concluded that the birds grew from gooseneck barnacles until fully feathered and then sprang out of the sea. Very imaginative!

Sunday, October 13, 2013

Locust Borer Beetle

A locust borer beetle, Megacyllene robiniae
Locust borer beetles can be found on goldenrod flowers now. You might take one for a black and yellow wasp if you look too quickly. Closer inspection will reveal their exceptionally long antennae; locust borer beetles are members of the family cerambycidae that are called"long-horned" beetles because of them.

They spend their larval stages on black locust trees. When they are not busy eating goldenrod pollen, the autumn adults can be found on locusts tree trunks, mating or looking for good places to lay eggs. The larvae hatch before winter and spend the cold months under the bark. When the weather warms, they'll burrow into the trunk and pupate. They emerge as adults in late summer and early fall and begin the cycle again.
The adult eats goldenrod pollen. Note that the third yellow stripe on its back is shaped like a W. 
One of the prettiest insects ever! 

Sunday, October 6, 2013

Picture-winged Fly

This is Delphinia picta, a picture-winged fly. Click on the photo to enlarge. The fly gets its common name from its striking wing pattern; it has two white triangles on the leading edge of each wing and a few decorative white swirls on a shiny brown background. Very attractive!  
Head-on, the fly looks like it is wearing a tiny gas mask. As it walks, it  moves its wings in  a rowing motion. 

Picture-winged flies lay their eggs in rotten vegetation. The larvae spend a few weeks feeding there, then pupate for a few weeks, and then emerge as adults. When the weather cools, late season larvae crawl into the ground and become quiescent for the winter. They following spring, they wiggle upward, pupate, become adults, and start the cycle again. 

I saw numerous picture-winged flies sunning themselves on benches in Brooklyn Bridge Park this summer (I'm assuming they were sunning, but maybe they were speed-dating). The next generation is surely sleeping under the grass now, not to be seen again until next spring .