August Has Gone By

August is over and we’re sliding into fall. Here’s a small sampling of sights I witnessed this past month above and beyond what I’ve previously posted.

At the top and below are pictures of Bembix wasps. The various, rather gentle, non-aggressive wasp species in the Bembix genus burrow into sand to house and feed their young. They feed the larvae flies. They’re often called sand wasps.

The picture above is of a Bembix wasp standing at the entrance to its burrow. The wasp is standing directly atop the entrance to the burrow which has been covered in order to conceal its whereabouts. In the photos below, another wasp emerges from its burrow after delivering a fly to its larval young.

Emerging from burrow after delivering fly to larva (left). Kicking sand back between its legs to cover entrance to burrow.
A few minor adjustments to the sand grains and the hole is covered (left). Can you see where the hole was?

Unlike cicada killers or mud daubers (also wasps) which capture, paralyze, and stock their burrows with living prey, laying eggs on the unfortunate prey, and ultimately sealing off the burrows to leave the hatching larvae to feed themselves as they grow, Bembix wasps feed fresh flies to their developing larvae.  They make regular trips in and out of the burrow to supply their larvae with fresh meat.

Cicadas are now calling out loudly with their buzzy songs from high up in the trees. The cicadas you hear as you walk along out of doors are annual cicadas. They’re here to mate and lay eggs. When the eggs hatch the larvae drop to the ground, burrow into the earth and spend the next phase of their lives, the larval stage, underground eating tree roots. Though their life cycle may be up to ten years, they seem to average three. There are more than a few species of these green, black and brown cicadas in our state, but you’d be correct in calling any of these mid to late summer insects “annual cicadas.”

Annual cicada on boardwalk.
Annual cicada from above.

Grass skippers are small, mostly brown butterflies with various light and dark markings on their wings. Their caterpillars are not as often encountered as with many of the larger swallowtail butterflies or large silk moths. So, when I came across a skipper caterpillar amongst the patch of partridge pea that I cultivate in Cath the Wind, I was excited. The caterpillar was not on the legume but a blade of grass (Japanese stiltgrass) which grew up between the pea leaves. It was wrapping itself in the leaf, presumably preparing to pupate.

This skipper caterpillar is drawing in the edges of the leaf with silk to make a shelter.
You can see the leaf beginning to enclose caterpillar.

I assumed, from looking at photos of other skipper caterpillars, that mine was a dun skipper. I later learned that it’s difficult to identify grass skipper caterpillars. The best way to correctly determine just what species it is, is to rear it. In other words, collect the larva or pupa, whichever you come across, take it home and let it go through its cycle. When it emerges from its chrysalis you should be able to correctly identify the insect. To some though, identifying those little brown butterflies known as skippers is only slightly less difficult than identifying their larvae, the caterpillars.

In mid August I was in the Great Lakes Region, New York, Michigan, and Wisconsin. While there I noticed many monarch butterflies moving south. I know that the peak monarch migration in New Jersey occurs around September 19, a few weeks later here in North Carolina. Even so, there were at least two early monarchs laying eggs on milkweed in the garden just outside the front door of the Butterfly House at the museum. There were also a handful of caterpillars which were several days old. Their eggs, the eggs they hatched from, must have been laid perhaps two weeks earlier.

Monarch butterfly egg (about 1 mm).
A closer look at another egg.
These monarch caterpillars are about 3-4 days old. Orange objects are oleander aphids.

Milkweed is a toxic plant, any insect that eats the plant also becomes toxic. Most of these insects advertise their toxicity by being brightly colored, typically red or orange. Besides the monarch butterfly above, which is orange, black, and white, and which is, as you know, closely tied to milkweed, there is an insect called the large milkweed bug. They eat the seeds of the milkweed.

I look forward to seeing milkweed bugs each summer because they’re a great insect to point out to summer campers when explaining their, and other insects, toxicity and its benefits. However, I didn’t see a single milkweed bug until summer camp had ended. They were late in coming this year.

Large milkweed bug on butterfly weed.

I was temporarily set aback when I came across the two insects in the photo below. I initially thought they were milkweed bugs, small milkweed bugs which are similar in coloration to large milkweed bugs but a bit smaller. But no, they were on a sunflower leaf, so not likely. I then thought, “perhaps elm seed bug, “ and settled with that until I got back to the office and had a closer look at the photos I took of the bugs.

The pattern on the back was wrong, not by much, but still wrong, for either small milkweed bug or elm seed bug. After some searching, I discovered the insects were false milkweed bugs. False milkweed bugs feed on sunflower seeds. Problem solved.

False milkweed bugs, mating.

A stop by the Red Wolf Enclosure often yields an interesting picture or two. Here, I walked up on an interaction between the adult male (1803) and one of his pups. The pup was apparently, and quite persistently, trying to get dad to regurgitate some of the food he just wolfed down. The big male was having none of it and made the point clear to the young wolf.

Puppy attempting to get an already chewed meal from dad.
Dad laying down the law. That’s mom in back.
All is calm.

Around the corner from the wolves you’ll find the lemurs to be accommodatingly photogenic. The lemurs are always doing something interesting, even when they’re doing nothing.

Mutual grooming.
Just sitting around.

Come on out and see for yourself. And oh yeah, take a child outdoors with you.

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.