Thistle community 2020

Thistle Community 2020

I usually have at least one thistle that makes it to a good size. I first got interested in Entylia carinata (Keeled Treehoppers) in 2015 when I had a thistle that grew higher than me by a couple of feet In 2019, there was one Thistle in the back yard that kept a colony going for the summer. In 2020 Two Thistle plants had grown up next to each other in the front yard. On June 9, 2020, I spied one or two adult Keeled Treehoppers on an Aster plant in the front yard (picture 1). I think they use Asters as a waystation as they move to a new Thistle. On June 3, there was already at least one Adult Keeled Treehopper on one of the two new Thistles (picture 2), and soon both were settled by several adult E. carinata. Every afternoon I dragged my folding chair out to that spot to photograph what would happen. By June 13, the Adults had already started laying eggs. In case you are still wondering what a "Keel" is, it's either of the two things that look sort of like Camel humps on the Adult's back.

One of the things I'm really fascinated by is the relationship between several kinds of Ants who interact symbiotically with the young of various other insects. In the case of E. carinata, one of the major Ant Nannies will be the Eastern Black Carpenter Ant. Even before the eggs hatch, here is one of those big Ants who can't wait for the nymphs to appear. It wants that honeydew, the rich exudate of the Nymphs! Here you see the Ant at the side of one of the Mothers, who is standing guard over her eggs. The Ant strokes the Hopper and a big drop of honeydew appears and then the Ant receives the drop.

From the moment the tiny Nymphs are hatched, the Ant seems to be impatient for the reward. What does it do to deserve the rich dessert? For one thing, there is an element of protection for the Nymphs. Another thing is that when the Ant cleans up the sticky treat, it is keeping the Nymphs cleaner and less prone to Fungus or other infections. But there is a time lag before the Nymphs are really large enough to satisfy the Big Eastern Black Carpenter. And this is where another less often seen ant comes in. This is the tiny Hairless Rover Ant, which used to be thought of as a bottom floor inhabitant. Since this little Ant is pretty much hairless, it prefers to be down on the moister ground. This summer I have seen the Hairless Rover all over the place, up off the ground. And in this case, they seem to enjoy nannying the baby Keeled Treehoppers!

As the nymphs get larger, the Black Carpenters come back and do more nanny-ing. Here is one running back and forth through the throng of Nymphs. Note how as the Ant comes by, the Nymph automatically extends its tail end to get "milked".

The nymphs start out minuscule, and gradually grow into more and more interesting-looking phases. There are lots and lots of them. Picture 2 shows a LOT. In picture 3, you see how colorless they are when they have just shed their old skin as they get older.

Picture 1 shows a nymph as it starts to get wings. In picture 2, the "keels" are showing. If you will click on picture 3, you can see how the skin is splitting as the Nymph gets ready to let a new Adult out!

The last few days of the Treehopper Season see the nymphs, one by one, converting into adults. In the last picture, all are Adults. A couple of days later, they have all flown off somewhere. Meanwhile, the Thistles have flowered and the fluffy seed messengers have all disappeared. I wonder where they will congregate next season. See you in June 2021!