The Bugs in the Backyard: Competitive Caterpillars

I know I have talked about this before, but I was recently reminded of an "inspirational" quote that said, "A flower does not compete with the flower next to it, it just blooms," or something to that effect. That's rubbish, of course, flowers compete with each other:

Of course, they don't literally push each other out of the way as it appears in this picture (which I took a few days ago, which means I am breaking one of my blog rules. Sorry), but they do compete for space, and sunlight, and nutrients, and water. They each try to be the one most appealing to pollinators. Everything in nature is competing for survival, and to pass on its genes. Sometimes the competition can be brutal. Sometimes it's subtle. And sometimes it's kind of funny, and it's this last scenario that played out in my backyard today.

There are two monarch caterpillars living in one of the milkweed patches:

I found them both on the same day, on the same milkweed plant. Over the last week or so I have been observing their progress. Some days I can't find both of them. Although they were on the same plant when I found them, they soon were on separate plants, but today they were back together on the same plant again. I expect them both to turn into chrysalides within the next day or two (which I may not see–they tend to wander off to pupate somewhere other than the plant where they have been feeding), and right now they are in the heavy eating period right before that happens. But hey, it's a big plant with lots of leaves, plenty for everyone, as long as everyone is just two caterpillars.

Anyway, here they are, each on their own leaf. The one in the foreground had spent some time eating a seed pod, but then found this leaf it liked. I took the picture and continued on my bug walk.

My bug walk was interrupted for about an hour, and when I went back outside to finish it I happened to see that there had been a change in the situation on the milkweed. Now both caterpillars were on the same leaf:

And the leaf was MUCH smaller. There's at least 20 leaves on this plant, and here they both are, eating the same one...

...It seemed like neither one really minded...

...Sometimes they got close together...

...But they each just kept chomping...

...And sometimes one would get too close for comfort and then–and I wish it was possible to photograph what happened then–one would headbutt the other.

...Here you can see the one on the right has paused in its eating, having recoiled in high dudgeon after one such insult.

Putting a bit more space between them...

I continued my bug walk, and spent some more time in the backyard, and I checked up on them occasionally:

Eventually one moved on. I don't know if it decided the leaf was too crowded, or if there was some other reason–generally they eat part of a leaf and then move on anyway.

Queen/King of the leaf has won the high ground, and the competition for that leaf.

Not that there's much left.

Eventually both had moved on...

... and this was what was left of the leaf.

This one went back to eating the seed pod (actually, I don't know if that was the one eating it earlier), and I was kind of surprised to see that, because I had never seen one eat a seed pod before, but I realized that that is because I have been adopting the caterpillars for the last several years and it never occurred to me to give them a seed pod. Just as well, I need the seeds for planting.

Backyard Bug of the Day:

A skipper. The most cooperative family of butterflies.

Now for some more leaf-sharing caterpillars:

The milkweed tussock moth caterpillars had gathered in a group under a leaf today.

It's like a really ugly 1970s carpet.

Although there were some stragglers that set off on their own.

Later in the afternoon I saw that they had moved to the top of the leaf and were eating it.

And even later they had eaten almost the entire thing!

One interesting thing about the milkweed tussock moth caterpillars: they have never been a common sight in my backyard. I don't even see one every year, and I have never seen them in a group like that, I have only ever seen solitary ones. I know from seeing pictures that they group together, but I had not witnessed it in my backyard. And this year, I have multiple broods of them in my backyard. There's the one above, that is the most advanced of the broods, and this one:

I am still not 100% sure these are milkweed tussock moth caterpillars, but they are starting to look more like them.

And today I found these:

You don't see monarch caterpillars like this, because monarchs lay eggs individually, going from plant to plant, leaving one egg on the underside of a single leaf. But some moths lay an egg mass with many eggs, like gypsy moths and tent caterpillars, and obviously milkweed tussock moths.

Other Bugs:

We were out last night and got home very late to find a pretty crowded front porch. There were two katydids...

... the first adult katydids I have seen this year.

And a lot of moths, two of which I photographed:

As for the bugs on my bug walk:

Scorpion fly. Female, I think.

Assassin bug nymph

Where was this when I posted all about eggs the other day? Shell fragment of a robin's egg.

Dragonflies:

Plant hopper

I couldn't find the new caterpillar that hatched yesterday, but I did find a recent hatchling on another plant.

Stilt legged bug

Backyard Amphibian of the Day:

Tiny, camera-shy frog

Beetle

For weeks I was seeing a lot of hopper nymphs on various kinds of vines around the backyard. I think they have all reached imago (adult) stage: