Early Fall Things To Discover

Top Photo: Yellowjacket picking over annual cicada.

The yellowjacket in the images above and below is scavenging protein from a dead cicada on the path. Yellowjacket larvae back in the hive are fed protein in the form of whole insects or chunks of meat harvested from caterpillars and other larger animals, even from a picnicker’s ham sandwich. The yellowjackets take the meat back to the hive and feed it directly to larvae in cells within the hive after it’s been chewed and conditioned.

Scavenging for protein.

I’ve read articles claiming yellowjacket nest sizes to include from several hundred to a whopping 250,000 individuals. While those numbers are perhaps related to latitudinal location of nest or hive (and the length of the growing season), that’s quite a range. But most authors seem to suggest from 250 to 3,000 or 4,000 occupants.

Working on a flattened pine sphinx caterpillar.

Just know this, if you disturb a hive, it’s likely that a good number of the individuals inside the hive will come out with the intention of driving away whoever it was that disturbed their focused busyness. I don’t think the difference between 250 and 250,000 angered yellowjackets are numbers you should be concerned with. One mad yellowjacket’s ire is bad enough. Most hives are disturbed accidentally so keep an eye out for areas where yellowjackets are seen flying in and out of, and avoid it.

A single yellowjacket departing subterranean hive.

Fall is the time of year yellowjacket numbers peak.

Roused out of a diurnal sleep by the weed extracting activities of horticulturist Lew in front of the Butterfly House, a pandora sphinx moth (Eumorpha pandorus) resettled some twenty feet away in a location suitable for photography.

Pandora sphinx moth.

Nearby was a cooperative pearl crescent butterfly. This is a common and widespread butterfly species inhabiting every county in North Carolina from the mountains to the sea.

Pearl crescent.

And finally, as I looked down into the shallow water of the wetlands from the floating walkway in Explore the Wild I could see small mollusk type creatures moving slowly about on the muddy, silty bottom of the pond. With my binoculars I could see a shell, tiny objects attached to the shell, and movement, but I couldn’t determine exactly what I was looking at.

Two mollusks on muddy bottom.

I acquired a net and captured two individuals, cleaned them off and hiked back to the lab where I could get a better look at the invertebrates, and maybe get a few photos.

I discovered they were bladder snails, physid snails. They’re one of the most common and widespread snails in the world. They’re used in the aquaculture world to clean aquaria. On the outside, they’re considered invasive.

physid snail (bladder snail).

They’re air breathing mollusks in the family Physidae. Being air breathing and an aquatic snail at the same time can be a problem.

Bladder snails move slowly and do not swim. They either climb to the surface on vegetation and other objects or float to the top of the water column to gather air. The snail takes in air from the surface and stores it in a bladder like cavity for long dives.

Eggs attached to snail’s shell.

The small elliptical objects on the snail’s shell in these pictures appear to be aquatic insect eggs, perhaps water boatman eggs. Water boatman have been known to lay eggs on shrimp and crawfish. It’s been suggested that this might protect the eggs from predation.

Water boatman eggs on head of crawfish.

I’m not sure depositing eggs on a shrimp or crawfish would have much benefit in keeping them safe from predators. Both shrimp and crawfish are prey for many species of fish, amphibians, reptiles, birds and mammals, including humans. The eggs would either be eaten raw by larger animals or boiled away in a pot of water with the crustacean as part of a meal.

Perhaps the water boatmen simply require a firm or hard surface on which to lay eggs, rocks or plant stems. Lacking those things, a crustacean’s exoskeleton or a snail’s shell will do.

By the way, water boatman eggs (called Ahuahutle in Mexico) were, or still are, harvested and ground into flour as food since the time of the Aztecs.

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