July, gone but not forgotten

On its way to the ocean via the Eno River, Falls Lake and Neuse River, Ellerbe Creek runs through our 84 acre campus. Before it reaches us, it flows under an interstate highway (twice), through a golf course, through quiet neighborhoods and under and through a mall, mostly unseen by the local human population. There are a handful of preserves along its 20 mile meander through Durham but for the most part, I’d wager, most folks don’t know it exists.

We, here at the museum are well aware of it’s existence. Our summer campers spend a good part of their time exploring Ellerbe Creek, as you can see above and below.

Summer campers searching for aquatic creatures in Ellerbe Creek.

By the way, belted kingfishers have been known to nest in the high banks of the creek.

Female belted kingfisher.

Autumn olive, one of the most invasive species of shrub in our area has at least one redeeming quality, it’s berries. Their sweet-tart taste makes them a hit with most campers even though, wherever it is they occur, they take over the forest understory, fields, hillsides, and more, shading and out-competing native plants. Late June-July is when the fruit ripens.

Some people call this plant silverberry.

Catalpa trees bring to mind many recollections. I can remember, as a kid in summer, walking around and showing off with a long cylindrical catalpa seed pod between my fingers pretending it was a cigar. We used to call the catalpa seed pods punks, although punks were something else altogether (punk – compressed sawdust on a stick used for personal mosquito control and a safe way for lighting fireworks. It’s something you light, which stays lit, and smokes). We did try to light and smoke the seed pods but of course, that didn’t work so well.

All that aside, down here in the south, around the last of June into July the leaves of catalpa trees are often covered with large black, white and yellow caterpillars, catalpa hornworms, or simply catalpa worms.

Catalpa worms are the larvae of Catalpa sphinx moths (Ceratomia catalpae). They, the caterpillars or larvae, are a favorite bait of fisherman. Ask most fisherman what a catalpa, or catawba worm is and you’d most assuredly get a rapid reply, “best darn fish bait there is!” They’re even raised and sold commercially as bait, the caterpillars, that is.

Catalpa worm on catalpa leaf.
Munching away.

Our catalpa worms are spared the hook, they apparently make it to pupate in the soil beneath one of the only catalpa trees I’m aware of here at the museum. The tree is on the Dinosaur Trail.

We have an exhibit in Catch the Wind called Vapor Rings. There are five stanchions which each hold up a drum-like device. Each device has vinyl material applied to one end and a hole in the other. When one strikes the material side of the drum it forces a current of air out of the hole which, if the drum is aimed properly, strikes a sequined board a dozen or so feet away.

Striking the drum.

Twice this season Carolina wrens decided to nest within one of the drums. So far, one nest has successfully fledged, I think, three young. The other nest, the last time I looked (7/28), had what appeared to be two nestlings inside.

Two eggs in the wren nest at Vapor Rings Exhibit.
What looks like two nestlings (7/28/18).

A check of the drum on July 31 revealed an empty nest. I don’t have an explanation for why the nest was empty, only a guess, black rat snake.

Dogwood sawfly larva.

Besides flowering dogwood, we have another species of dogwood growing here at the museum, silky dogwood. It’s a native shrub which grows in wet areas. There are several silky dogwoods growing in Explore the Wild next to our wetland.

Each year the dogwood is attacked by dogwood sawfly larvae. I’ve read that in their early stages of development, dogwood sawfly larvae are covered with a white waxy substance. Later molts are supposed to leave them smooth amber with black dots. I see far more white waxy larvae than I do the yellowish larvae later in the season, so I’m not sure how accurate that statement is.

Although they look a lot like caterpillars, these insects are definitely not caterpillars. In fact, sawflies are relatives of bees and wasps (hymenoptera), not butterflies and moths, which is the order of insect caterpillars belong (lepidoptera).

Without the white waxy coating.
Often seen curled up under the leaves of the dogwood.
A small sampling of the dozens of sawfly larvae seen this year in Explore the Wild.

Dragonfly numbers seem low this year. However, a female eastern pondhawk brightened up the day for a group of summer campers.

Female eastern pondhawk.

Galls are a subject often brought up on walks with summer campers around our campus. Many of the plants we come across have their own gall producing, or gall stimulating, insects. Golden rod has several species of insect which cause it to produce galls. The one below is caused by the goldenrod gall fly.

There’s a goldenrod gall fly larva munching away inside this gall (about 1″).

Grape vine beetles eat grapes and grape leaves. The larvae eat rotting logs and roots of dead trees. We, summer campers and me, saw one crossing the path in Catch the Wind during July. We investigated.

Grapevine beetle.

The beetle is also known as spotted June beetle.

Spotted June beetle accepts a ride from a happy camper.

The campers and I came upon a medium sized orange moth with one white spot on each forewing. It was an orange-striped oakworm moth. We’ll see more of this creature later in the season (typically August) when it’s caterpillars lay waste to our oak trees.

Orange-striped oakworm moth.

Actually, according to my research, the caterpillars, though there may be hundreds of caterpillars in a single oak tree, don’t do as much damage as it may seem. The caterpillars are active late in the season, most of the tree’s growth has already taken place by the time the caterpillars appear on the scene. Whether that’s true or not, that’s there’s little permanent damage, I have no proof. But, our trees are attacked each year (same trees) and they seem to be doing fine. Of course, they may have grown taller and broader without the annual caterpillar assault.

Orange-striped oakworm caterpillars.

And finally, if you happen to be at the red wolf enclosure and don’t see any wolves, look closer. The wolves have been switching out their individual favorite spots. One day they’re here, the next they’re there. But one spot is a perennial favorite, behind two large pines. Let me explain. There are two large loblolly pine trees near the back and top of the enclosure where one or both of the wolves often lay in the afternoon.

The adult red wolves at rest, behind the trees. I see a head, a belly, and at least four feet of two different wolves.
Area enlarged above.

Keep an eye out for the wild life!

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