Saturday, September 23, 2006

At the Shakespeare Garden

Regina Alvarez, Central Park's Woodlands Manager is a friend from early Pale Male days when she was the Zone Gardener at the Model-boat Pond. Yesterday she sent in these photos of insects taken in the Shakespeare Garden. She didn't send IDs for any but the Assassin Bug. I happen to know the moth. But the wasp/fly? Yikes. I'm guessing this one's a Syrphid Fly, a wasp mimic, and not a wasp, because it doesn't have a real wasp waist. As soon as I see Nick Wagerik, our entomology guru, I'll get the scoop. Note the cool antennae on the moth--bipectinate or featherlike, that arrangement is called.

PS If you click on the photos you can make them bigger--and see more amazing details.

A Syrphid fly [I hope]

Virginia Ctenucha [a moth]

same moth, frontal view

Assassin Bug [and Nick Wagerik's finger]

Friday, September 22, 2006

Surprise in the milkweed

The other night I was shining my flashlight up and down the tropical milkweed (Aesclepia curassavica) just in front of the food stand at the Model-boat Pond. Here's what I was looking for:

I was looking for Monarch Butterfly caterpillars. They feed on milkweeds and I had seen five or six of them chomping away on these very plants the night before. I had photographed the one above that night. Tonight I couldn't find any. I was about to give up my search when I did a double-take. Something was a little out of place on one of the flower stalks.. Here's what I found.

It's a Differential Grasshopper [Melanoplus differentialis], one of the largest and handsomest of our orthopterans. It's easily identified by the black herringbone markings on the upper part [femur] of its hind legs.

Thursday, September 21, 2006

The cicada's avenger

Bill Trankle, a regular correspondent on these pages, writes from Indianapolis:

Your late post of the activities of the cicada-killer wasp females reminded me of something as well; I think I may have discovered a rather unusual predator of the C-K wasp, specifically their buried future-offspring: The common mole.

As I told you earlier this summer, I've had a banner year for Cicada-Killer wasps, and the last two active tunnels must have been huge affairs, judging by the enormous mounds of dirt thrown out by the females. I actually got to watch a female enter one of the tunnels on two different occasions with cicadas in tow.

However, both of those tunnel complexes are no more, as far as I can tell. Perhaps it is coincidence, but they were both dead-center in two separate dirt eruptions that are the results of moles coming to the surface. I know moles will eat just about everything, and perhaps they enjoy the un-dead cicada that the wasps leave for their unhatched larvae (if the moles eat the cicada, I'm sure they snack on the larvae as well!). My neighbor across the street had a C-K wasp burrow that met a similar fate. Mother Nature does like to keep things interesting.

Note from MW: At the Central Park BioBlitz that took place on June 24, 2006, a new species was added to the mammal list: mole, as the disappointingly non-scientific results of the Bioblitz's survey simply named it . It was probably an Eastern Mole, Scalopus aquaticus, the most widespread mole in the northeast US. That is, if it was there at all. I understand that the mole was not actually seen on the day of the Bioblitz, but was only ID'd by its droppings. I'd like to know more about how these were analyzed. Basing my judgement on the slapdash way the mammal team posted its final report [check it out on the Explorers Club website] I have quite a few doubts about that mole...

But in any event, according to the Kaufman Focus Guide: Mammals of North America, Eastern Moles don't exactly "eat just about everything," as Bill suggests. In the Order Insectivora, Eastern Moles eat insects and grubs but they "especially like earthworms " according to the book's authors. The moles on Bill Trankle's lawn may not have had their favorite dinner there, but they might have been quite satisfied with Mom Cicada-Killer Wasp and her offspring, as well as whatever left-over Cicada they found in the wasp nest.

Wednesday, September 20, 2006

A beautiful almost-fall morning

Photos by Lloyd Spitalnik -- all taken on Saturday, Sept 16, 2006

Left, Rose-breasted Grosbeak male [note the very faint rose breast] and above, a Yellow Warbler. Both species were among those seen this beautiful morning, three days before the autumnal equinox, by the Early Birders. See list below:

Date = 9/20/06
Site = Central Park
Observers = Early Birders
Reported by = Ardith Bondi

Double-crested Cormorant (flyover, Lake)
Green Heron (Bamboo near Oven)
Black-crowned Night-Heron (Balcony Bridge)
Canada Goose
Gadwall (male and female, Turtle Pond)
American Black Duck (Balcony Bridge)
Rock Pigeon
Mourning Dove
Red-bellied Woodpecker
Yellow-bellied Sapsucker (Strawberry Fields)
Northern Flicker (several)
Olive-sided Flycatcher (Strawberry Fields)
Eastern Wood-Pewee (Strawberry Fields)
Warbling Vireo (Riviera)
Blue Jay
Carolina Wren (Strawberry Fields)
House Wren (Maintenance)
Ruby-crowned Kinglet (opposite Lower Lobe)
Blue-gray Gnatcatcher (Willow Rock)
Swainson's Thrush (south of Weather Station and Triplets Bridge)
American Robin
Gray Catbird (many)
Brown Thrasher (several Strawberry Fields, Maintenance)
European Starling
Yellow Warbler (Strawberry Fields)
Chestnut-sided Warbler (west of Lake)
Magnolia Warbler (several)
Black-throated Blue Warbler (several, male and female)
Black-throated Green Warbler (Strawberry Fields, Lower Lobe, walk S. of
Turtle Pond)
Palm Warbler (opposite Lower Lobe)
Black-and-white Warbler (several)
American Redstart (several)
Ovenbird (Strawbery Fields)
Northern Waterthrush (Triplets Bridge)
Common Yellowthroat (several)
Wilson's Warbler (several, one bathing in the wet grass, Strawberry
White-throated Sparrow (Strawberry Fields)
White-crowned Sparrow (imm Maintenance)
Northern Cardinal
Rose-breasted Grosbeak (several, Strawberry Fields, south of Weather
Common Grackle
Baltimore Oriole (Maintenance)
House Sparrow

Tuesday, September 19, 2006


Cicada Killer Wasp dragging its victim down a lamppost
Photo by Regina Alvarez

Last night, for the first time since June, not a single moth visited the Moth Tree. The end of the season is upon us, at least at the Moth Tree. We may bring a light to the Shakespeare Garden during the next week or two in hopes of attracting a few flower moths and loopers. There's a Monarch Chrysalid at the Model-boat Pond. Any day now a beautiful butterfly will emerge. The crickets and katydids are still singing throughout the park -- at least 5 different species.

But as summer turns to fall, so insect life diminishes. The days are getting shorter and cooler. Time to turn our attention elsewhere.

Last night, on the way out of the park, Jim Lewis and I found one last Cicada Nymph case. Today at least one last Cicada sang its loud, buzzy song in hope of attracting a mate. Earlier we'd watched numbers of the lovely green insects emerging from their ugly brown cases. Now, the cicada season is drawing to a close, and with it, the time of the Cicada Killer wasp.

This morning I remembered a report I'd written more than a month ago about these large wasps and their very specific prey. I'd forgotten to post it. Here it is.

August 12, 2006
Last night as three of the Moth gang headed for home, the humans rejoiced in the newly cool, crisp weather--a heat wave had just ended. Meanwhile the moths showed their invertebrate preferences by staying away from the Moth Tree. Frustrated, we stopped at Cedar Hill to check out the Cicadas and the Cicada Killer Wasps.

At the rock outcripping near the south end of the hill we found one active Cicada Killer nest. There was a fresh [i.e. dampish] mound of excavated soil at the entrance to a conspicuous hole. Peering into it with a bright flashlight [ my Surefire--the brightest I've ever had], we could see the beginning of the wasp's long tunnel.

We waited at the mound for two or three minutes and finally ...action. We saw a little movement at the hole entrance, and out came the wasp, rear-end first. As she came out she pushed out new soil from the excavation.. [Only the female wasps make the nest.]

When the tunnel is completed the Cicada Killer Wasp will lay her eggs in carefiully prepared cells deep underground. Then she'll go out hunting for a cicada. . She'll drag a living, though paralyzed Cicada down the tunnel to the nest. When the wasp larvae emerge they'll feed on the live cicada. Ugh!

Monday, September 18, 2006

Evolutionary wonders

All photos by Lloyd Spitalnik

Insect #1.

Insect #2.

At first glance [and perhaps at tenth glance] you might think that the two insects above are closely related. You may already know that insect #2 is a wasp, Ancistrocerus adiabatus, since I posted it here a few days ago and pointed out the "smiley face" on its thorax. Consequently you might think that insect #1 with the V on its thorax is also in the wasp family [Hymenoptera].


The first insect, photographed last Saturday at Turtle Pond is not a wasp. It is a syrphid fly, Spilomyia longicornis and belongs to the Fly or Diptera family.

Many Syrphid flies mimic bees or wasps in appearance. This is an example of Batesian mimicry, which protects them from falling prey to birds and other insectivores who would normally avoid eating true wasps because of their sting. Evidently the animals that are fooled by these wasp mimics cannot count, for a Syrphid fly and a wasp can be distinguished by the number of their wings. All flies have only two wings, [Di = two, Ptera = wings] while the wasps and bees these are mimicking [and indeed most other insects] have four wings.

Batesian mimicry, by the way is named for Henry Walter Bates, a British scientist who studied mimicry in Amazonian butterflies during the mid- and late nineteenth century. It refers to two or more species that are similar in appearance, but only one of which is armed with spines, stingers, or toxic chemistry, while its apparent double lacks these traits. The second species has no defense other than resembling the unpalatable species and is afforded protection from certain predators by its resemblance to the unpalatable species, which the predator associates with a certain appearance and a bad experience.

Below are a few other stunning photos of some insects in Central Park taken by Lloyd a few weeks ago.

Blue Dasher [female]

Weevil Wasps [mating]

Ailanthus Webworm Moth
[yes, it's a moth]