Posts Tagged 'cicadas'

Brood X: A Spectacular Spectacle

The abdomen is mostly hollow.

Brood X is nearing the end of its absolute reign upon the regions graced with it. The tiny larvae are probably already dropping out of their twig nests and burrowing into the earth. They will emerge in 2038. What will be the state of the planet then?

2024 is the next periodical cicada year: the Great Southern Brood (Brood XIX; 13-year cicadas) will emerge across fifteen southern states. Brood XIII also emerges in 2024, in IA, IL,IN, and WI. Here’s a schedule.

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Yes, More Cicadas

Robert Evans Snodgrass’s Insects: Their Ways and Means of Living, first published in 1930 and then republished by Dover, has an excellent chapter on the periodical cicadas with some fine illustrations. Turns out the abdomen of the adult is mostly hollow.

The newly emergent adult cicada has to harden off and darken over a few hours before getting down to business. Most of them do this at night, but there are sooo many that you can find them in this soft, vulnerable stage during the day, too.

Business! And so, after seventeen years, a new generation of Brood X begins. The female cuts nest chambers into the underside of twigs of trees and shrubs and deposits her eggs into these. She has 400-600 eggs and lays two dozen or so in each nest. Larvae drop down on to the ground when they are about 1/12th of an inch long. Then they burrow down to become subterranean. They spend all those years underground growing larger, slowly. Usually they are no more than two feet below.

Massospora cicadina, a deadly fungus, claims many of the cicadas, rotting the abdomen out. This is one of those “zombie” pathogens that take control of the animal, as detailed here.

I got some shots of female and male Pharaoh Cicadas that WordPress won’t upload here for some reason. Too damn sexy, I guess.

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Cicada Chorus

The communal roar of the cicada chorus, a dynamo seventeen years in the making, and the individual buzzing and rustle of the periodical cicadas at Princeton Battlefield State Park. The thicket of understory and woods pictured, bordering a trail and a meadow, was the loudest, most active spot here on Thursday. The cicadas were flying, and sometimes landing on vertical things—like humans. One landed on my back and started crawling up. They tend to move up. Its science-fiction buzz near my ear was uncanny.

Brood X

There are actually three species of periodical cicadas that make up Brood X. Magicicada septendecim or Pharaoh Cicada; Magicicada cassinii or Dwarf Periodical Cicada; and Magicicada septendecula or Decula Periodical Cicada. We call these seventeen year cicadas (there are also some thirteen year ones), but these are median spans: Decula can live from ten to twenty-one years. Here’s a guide, which also includes recordings of the chorus and songs.

Many are called. We’re talking billions. As many as 1.4 million per acre, or so says an often repeated factoid. We couldn’t walk around Princeton Cemetery without stepping on the husks. The side-street leading to the cemetery’s gate was piled up with shells and corpses. There’s a lot of carnage.

Fewer are chosen. A lot don’t even make the transformation to the above-ground adult. Disease and predators take a fearsome toll. (This should be a baby-boom year for everything that eats these.) And, of course, our insatiable imperial desires to take over the plant rob them of life, too. The Long Island population is a case in point–but there’s at least one Brood X observation on iNaturalist now.

I know some people are grossed out by all this. And I don’t envy the clean up. But what an astonishing, amazing spectacle this is.

Breaking: yesterday, a sighting was reported in Prospect Park!

Brooding

Princeton Cemetery.
Three pictures of the same individual at the Charles H. Rogers Refuge

New York, except possibly for parts of Long Island, are not in the range of Brood X Magicicada genus periodical cicadas. We had to travel to Princeton, NJ, practically their northeastern-most outpost, to see them. And hear them: a thrumming incantation, background for much of our time in the town.

Exuvia of the larval form here, along with emergent adult.
This is the form in which they spend all those years underground, sucking on plant roots.
Then, some seventeen years after their birth, they emerge, break out of the carapaces, unfurl their wings, and set about mating.

In the thick of it, they’re en masse. Underfoot, piled up along the edges of streets, hanging off trees by the thousands. Throbbing in the trees like some otherworldly dynamo.

Cicada

Swamp Cicada (Neotibicen tibicen) orbits a butternut hickory nut.

Emergence

On Saturday, your correspondent stumbled upon a cicada emerging from its larval husk.
The folded forewing has sprung from the exoskeleton, but the hindwing remains inside. The left hindwing, on the other side, was free soon enough, but this right one would remain inside the tight confines of the husk for the entire time.
From below. This occurred about four feet up from the road, the tree coming out of a steep bank. I counted a dozen other exuviae on the trunk or on the ground around this linden, a record number at one tree (by my count).
Right forewing uncurling.
The wings were very soft. The breeze made them flap about like streamers. You can see the right hindwing still folded up here.
From when I spotted it to final breakout, it took about an hour and a half, late morning into the afternoon. This is typically a nocturnal process: they’re utterly vulnerable to predators when they’re struggling, and all soft and juicy, too.
Just before the fall… because when you’re perpendicular to a tree, there are only so many places to go when you let go….
Hard to see the exuvia, but it is just to the right of center close to the top. The fresh green bug fell about three feet, bouncing a bit, but managed to stay on the tree trunk. It slowly turned around to point up and parked itself that way.
The right hindwing was still crumpled when I left. This one needed to harden off, stiffen the wings by pumping fluid into them, and start to take on their darker, mature colors.

An Ecosystem

On Monday, we started with cicadas. I’ve been trying to get a photo of a Cicada-killer Wasp with her six mitts on a cicada. Thrice now laden-wasps have zipped by me, white underside of their prey visible, but I haven’t been quick enough with the camera. ONce they land, the wasps are quite quick into their nests.
And here’s why, maybe. A Northern Mockingbird beat me to the scene! Almost as soon as the wasp landed her prey at her nest, this bird flew in and grabbed it.
Flying off to a nearby tree, the bird then proceeded to break the bank, or smash the exoskeleton of the cicada. There was much jabbing to get to the meat within.
The bird ate most of this morsel.
And took the rest to this one’s sibling, who was further up in the tree and unseen. But not unheard.

More Wasps

This Cicada-killer Wasp was emerging from her nest. She had just deposited a paralyzed cicada inside and, presumably since this is what they do, laid an egg on the cicada. I tried to get a photo of her carrying her progeny-to-be’s food inside, but she was too fast for me. I waited for about fifteen minutes to see is she would return with another cicada. Not on my watch. I could hear three cicadas in surrounding trees.
About ten feet away, on the road, this one patrolled the entire time, often perching, occasionally tangling with another passing by.
Elsewhere in Green-Wood: the lower nest here (the dirt slide is more than a foot long) has been here since at least July 28. Besides the second nest seen here, there were four others in this area. Most were on the flats above this slope.
This is that same lower-on-the-slope nest seen in the two-shot. It poured the afternoon before this picture. There has already been some maintenance.

And one more nest appeared this weekend.
This is some sexual dimorphism, isn’t it? Female on the left, male on the right.

Remember, it’s the larval form that eats the cicada. The adults eat very little, says bugguide. I have seen them taking nectar at flowers before. Recently I hit the mother (and father) lode of feeding for these large wasps. Stay tuned.

More Cicadas

I’ve seen and photographed more adult cicadas this year than I ever have before. The spent larval husks are easy to find, just look on tree trunks… and leaves. This quartet, plus another that fell by the wayside, were on a single horse chestnut.
Of course, most trees I look at don’t have any of these exuvia on them. But they also show up in more surprising places, like this Asteraceae less than a foot off the ground.
Some of the adults have been in the tall meadows in Green-Wood. They’re pretty skittish, giving a zzzt sound when they’re spooked.
This one flew away and then back, into this tree.

All of the above are side-views, the best available for these individuals. Makes them hard to figure out as to species.This one, however, is iNaturalist approved as a Swamp Cicada (Neotibicen tibicen tibicen). The vocalization of Swamp (also called Morning) Cicadas are similar to Linne’s Cicada Neotibicen linnei.
Might this be a Linne’s Cicada?
I think so.
This one made a couple of buzzing attempts to get out this mesh fencing. The fencing had rolled over, off the ground, so I gently tapped the creatures so that it fell down, as far as the reach of the mesh. It zooming out of the trap and across the street. (Note the chalky white of the underside. We’ll return to this later in the week.)
Do I think there are more cicadas in Brooklyn this year than, say, last year? Not necessarily. But I have gotten much better at spotting them.


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