A Clone is Born

Purple-spotted lily aphids, Macrosiphum lilii. Click to enlarge.

This is a picture of the lower surface of a lily leaf, flipped over. I took it in the Shakespeare Garden in Central Park in June. Look what's going on underneath! The big aphid in the upper left of the group is giving live birth to a tiny red-eyed baby.

The nymph is exactly like its mom except for size. It's a clone! Throughout the summer, aphids in this genus reproduce without sex by a process called parthenogenesis. Offspring develop from unfertilized eggs that do not undergo meiosis.

This method of reproduction is one of the reasons that an infestation of aphids can grow so quickly -- no need to date and mate. If an infested plant gets too crowded, winged females may be born and fly to another host plant. Near the end of the year, after many parthenogenetic generations, males and sexually reproducing females are born. They mate and lay eggs. The eggs lie dormant over the winter to hatch in spring and start it all over again.

An odd thing about aphids that reproduce like this is the possibility of telescoping generations: a female may be carrying an unborn daughter that is parthenogenetically pregnant with its own daughter. Like those nested Russian dolls. Cool!

Meet the Yellow-collared Scape Moth

The yellow-collared scape moth, Cisseps fulvicollis. Click to enlarge.

I found this moth near Atlantic City, New Jersey, in September, 2012. It is black with bright yellow trim, slender, and about half an inch long. It was nectaring on goldenrod at mid-day. Almost as if trying to pass itself off as a wasp.

It is Cisseps fulvicollis, a wasp-mimic member of the Tiger Moth family, Arctiidae. But it is all moth at heart. They fly at night, too, and are attracted to lights.

A scape is the lowest section of an insect's antenna; theirs must have really impressed the entomologists who named them.

Along the East River

I took a cold walk by the East River today. Brant geese, Branta bernicla, were lunching on the lawn in Brooklyn Bridge Park. 

Brant are often mistaken for Canada geese, but they are different species. I've written about their differences; click here for that blog. 

The lawn the brant geese were trying to eat turned out to have too much human traffic for comfort. The flock flew away, silhouetted against lower Manhattan. 

There was a female red-breasted merganser, Mergus serrator, dozing among the pilings south of Pier 1. She had her head turned back and her beak tucked into her feathers. She didn't raise her head, but she was watching me. Expand to full screen, and click to enlarge the photo and you will see her dark eye. Also note the crazy hairdo, and the Dr. Seuss-like reflection of her head in the water. I have written about this duck before; click here to see a picture of the red-eyed male. 

Beautiful ring-billed gulls, Larus delawarensis, were riding the river swells, pecking tidbits from the water. 

Click on the photo to enlarge. 

Other ring-bills were dining on takeout. 

And the flag on the Brooklyn Bridge was at half mast for Ed Koch. 

Katydid!

I found this katydid in Brooklyn Bridge Park on June 1, 2012. It's the only one I've seen there -- they can be hard to spot. 

It was sitting in a locust tree where it blended in extremely well with its leaf colored body and leaf-shaped wings. Click to enlarge.

I suspect it knew something about the partially eaten leaves all around. After noticing me, it slowly walked away and disappeared into the foliage. Great camouflage!

Nothing to see here! Leaves, just leaves...

Brooklyn Bridge Park Blog has written a feature about me! Click here to read it. 

Tiny Praying Mantis

A praying mantis nymph on my thumb. I found the insect on a bush by a path in the water garden in Brooklyn Bridge Park. Click on it!

I took this photo in June 2012. A miniature praying mantis is sitting on my thumb. It is a praying mantis nymph, an immature stage, and a very cute example of how insects grow.

There are two kinds of insect metamorphosis: complete (also called holometabolic) and incomplete (also called partial or hemimetabolic). The monarch butterfly is a well-known example of an insect that undergoes complete metamorphosis. Its life stages are egg, larva (caterpillar), pupa (chrysalis), and adult. Caterpillars have several stages, growing larger and shedding their skin for each.

The praying mantis grows by incomplete metamorphosis in which its appearance changes less dramatically. Its life stages are egg, nymph, and adult. Nymphs resemble adults but are smaller and lack adult features like wings and functioning genitals. A praying mantis grows through several nymphal stages, increasing in size and shedding a skin for each.

The insect in the photo will have completed its life by now. Adults die when the cold weather comes. But with luck it mated, if male, or, if female, mated and left an egg case to overwinter. Next summer I'll check the bush where I found this one and look for its children.

Ogden Nash wrote this poem called The Praying Mantis:

From whence arrived the praying mantis? 

From outer space, or lost Atlantis? 

glimpse the grin, green metal mug

at masks the pseudo-saintly bug,

Orthopterous, also carnivorous, 

And faintly whisper, Lord deliver us. 

Ring-billed gull eats pizza

A ring-billed gull, Larus Delawarensis, in non-breeding plumage, sitting on a fence by the East River in Brooklyn Bridge Park. 

Mmmm... Pizza.

Click on the photos to enlarge. 

On second thought, make that to go. 

Wait. There's pizza?

Amish Mules

Handsome mules! 

I'm going rogue this week and writing about animals that are neither urban nor wild. Mules! I saw these in Lancaster County, Pennsylvania, this summer. Amish farmers there use them instead of some modern farm equipment.

Mules are hybrids of two equine species; the mule's father is a donkey and it's mother is a horse. Mules themselves can be male or female, but they are almost always sterile -- it has something to do with the different number of chromosomes their parents have: horses have 64, donkeys have 62. Mules end up with 63. Pennsylvania farmers breed a large female draft horse like a Belgian or a Percheron with a big male donkey to produce the huge lovely and powerful mules pictured.

We need a special vocabulary to talk about mules. A less commonly successful cross between a male horse and a female donkey produces an animal called a hinny. A male donkey is called a jack. A female donkey is called a jenny or a jennet. Male mules are called horse-mules or jack-mules, but if castrated, john-mules, although that term is sometimes also applied more generally to all male mules. Female mules are called mare-mules. Some female mules have estrus cycles and are called mollies, but that term is sometimes applied to all female mules. On very rare occasions a stallion can impregnate a mollie to produce a hule!

Mules may be sterile but they are not sexless or celibate. They can and do copulate, they just can't make little mules. Aside from not being able to breed, they inherit good traits from both parents. They are strong, smart, patient, surefooted, and beautiful.

Click to enlarge. 

Mules have a reputation for being stubborn. But that may just be a well-developed sense of self-preservation. They will not willingly put themselves in danger and will stop to evaluate new situations before jumping in. And they famously stop dead if an attempt is made to overwork them or get them into trouble. Harry S. Truman said this: "My favorite animal is the mule. He has more horse sense than a horse. He knows when to stop eating -- and he knows when to stop working."

A donkey. Check out the tail. 

It almost never comes up in Brooklyn, but you can tell a mule from a donkey by looking at its tail. A mule tail looks like a horse tail. The donkey's looks like a cow's -- most of it is covered with short hair and it has a tuft at the end, like that thing you used to play pin-the-tail-on-the-donkey with.