Thursday, August 1, 2019

Trying To Do The Right Thing

For the last couple of years I have raised monarch butterflies in my house. I admit that the first time I adopted a caterpillar I did it because I thought it would be interesting to be able to watch the life cycle of the caterpillar. That caterpillar was very close to becoming a chrysalis, so I only had to take care of feeding it for a couple of days before it transformed, and then it was just a matter of waiting for it to emerge. I woke up at 6 a.m. on the day that it was going to eclose (emerge from the chrysalis as a butterfly), and sat there for hours waiting to see the wondrous event. It was quite exciting and moving. I loved it. I adopted more caterpillars that summer because I enjoyed the experience, even though with the other caterpillars, which were in earlier instars when I adopted them, it turned out to be a bit more work. I don't remember how many butterflies I released that year. I do remember that one of them had a deformed wing, but she was still able to fly, so I thought that was okay. I have continued since then to adopt monarch caterpillars to raise in my house because I thought I was helping a species that could use some help. I have already been trying to help them by planting milkweed, their host plant, and giving seeds to other people to plant, and also having other flowers in my yard so that the adult caterpillars have a food source even when the milkweed flowers have past their bloom. In the wild, monarch caterpillars have a 1 in 10 chance of making it to adulthood. My success rate has been much higher than that 10%, even though I have lost a few. A couple of new hatchlings didn't make it. One turned out to have been infested with some kind of fly; it failed to pupate and instead curled up and turned black. I isolated it in a sealed container, and one day I noticed that there was a fly inside the container; it had emerged from the carcass of the caterpillar, where it had grown and pupated itself. I had one other with a deformed wing, and one was lost to an unfortunate incident involving the vacuum cleaner. I still feel bad about that last one.

It really is quite a bit of work taking care of a lot of caterpillars, but like I said, I thought I was helping. Then last year I happened to read several articles, diatribes, really, about how people like me who "raise caterpillars in their dining rooms"–how did they know I kept them in the dining room?–are doing more harm than good. Some of the articles at least admit that we mean well, but some of them are really harsh, making people who adopt caterpillars sound like a bunch of selfish jerks who don't know what they are doing, and who are each contributing to the demise of the entire species. Caterpillars raised in captivity are susceptible to disease, and we fools are just contaminating the entire species. As it turns out, those butterflies with deformed wings were probably infected with... well, I don't know what, because I am an uninformed fool. Some kind of fungus, I think. I was supposed to be testing every butterfly, apparently, by removing some scales and examining them under a microscope. (I do have a microscope, but it's not powerful enough for that). I should just leave well enough alone, the internet cried.

So, maybe I should do that, I thought as this summer approached. I still have my milkweed to feed the caterpillars in the wild of my backyard. I still have other flowers to feed the adult butterflies. I should just leave it at that, because I don't want to contribute to the demise of the species, and I don't want to do more harm than good. But here's the thing. I had more than a 90% survival-to-adult rate for my caterpillars. Yes, there were two with deformed wings, but the vast majority of the caterpillars I adopt are past the first couple of instars. Chances are they were already infected when I adopted them, and I didn't have other infected ones after them (the two I had were years apart). And maybe being in my caterpillar enclosure, where I clean up the frass and replace the newspaper so it's clean, they are in close proximity to other caterpillars, but they are in close proximity in the wild, too. Remember the two who were competing over the same fragment of leaf? And there can be several per plant, and many per milkweed patch. If there is fungus there, they are all being exposed to it.

This year I have seen many monarch eggs. I have seen quite a few tiny, new hatchling monarch caterpillars. I have seen very few of them past their first couple of days. Yes, they are hard to find, but if they survive, they eventually become quite easy to find with their bold colors and stripes. If they were still on the plants where they hatched, or even nearby plants, I would see them. And I am not seeing them. Yesterday I couldn't find any. Today I found two new hatchlings, and one that appears to be several days old. But by now I should be seeing quite a few that are in the middle instars. And I'm not. IF the four larger ones I have seen managed to become chrysalides, and IF they make it through pupation and emerge as adults, though that is probably more than a 10% survival rate, it's still way lower than the survival rate in my dining room. Caterpillars have lots of predators. I watched several be milkweed tussock moth caterpillars be preyed upon by anchor bugs. The same could be happening to the monarch caterpillars, by many species of caterpillar killers.

Was I doing more harm than good by raising butterflies in my dining room? Am I doing the right thing by letting nature take her course, even if she has a much lower survival rate than my dining room?

I don't know.

Here are the monarchs I saw today:
 This one is almost a week old, I think?

These other two are very new, the first one probably hatched today, the second yesterday:


Backyard Bug of the Day:
 In a sense, today's Backyard Bug of the Day is the same as yesterday, but since they are in different life stages, and very different forms, it is allowable for me to choose this, the red milkweed beetle larva.

And for a bit of interesting biology, this is also a beetle larva:
 I don't know what kind. It looks a lot like a lady beetle larva (I know, we've been over this), but not exactly.

Lately I have learned something interesting that also solved a mystery for me:
 I found out that this...

 ... grows up to be this.

The nymphs were ubiquitous for a couple of weeks, and now the adults are:


The black-eyed Susans have wanted in popularity this last week or so, but there are still some bugs to be found there:
 In this tiny patch, two Orthoptera species, a katydid...

 ... and a grasshopper.

 An interesting egg, on black-eyed Susan. I presume it must be from some species of bug that has been on those flowers lately, but I don't know which one.

Jagged ambush bug in goldenrod:




 Robber fly

 Moth

I found a new brood of milkweed tussock moth caterpillars. Of the other three broods I saw only one caterpillar. I wonder how much of this is because of dispersal, and how many have fallen prey to other insects or birds?

I found a plant with a lot of ants tending to herds:
 The leaves had groups of small insects in lines down the middle rib, with the ants patrolling the leaves and stems of the plant. Normally when I try to get pictures of this kind of scene the ants ignore me, even if I put my hand on the plant, but not today. I took hold of this leaf to try to get a close-up of the insects the ants were tending and the ants freaked out. They crawled onto my hand–quite a few of them–and I had to shake them off. I thought they were going to bite me. I hope they were able to find their way back, they should only have landed on the plants nearby.

 I didn't get a good picture of their flock, but they looks sort of like hopper nymphs.

I am okay with not seeing cicadas much because they are mostly up in trees, and I am okay with not ever getting a chance to see one molting because they do that up in trees, but this one molted right on the side of my house just beside the back porch, and I missed it!

 Moth

Arachnid Appreciation:
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 Speaking of milkweed tussock moth caterpillars falling prey to other arthropods...

 
 Crab spider eating MTMC.

There was a disconcerting incident involving the Backyard Reptile of the Day:
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My husband had just gotten in the car to go run an errand while I was working in the backyard, and he beeped the horn and called to me to get my camera:
While he was in the car a snake climbed up onto the hood and then slid under it. My husband had the hood up by the time I got there.

 Eastern rat snake. You can just barely see the checkerboard pattern on its underside.

 Keeled scales along its spine. It is patterned when it is a juvenile, and it looks like this one has not quite lost the pattern and turned all black yet.

 My husband tried to lift it off with a stick, but it ended up turning around and then disappearing into a gap in the chassis (I think that's the right word). I have no idea where it ended up, but I am now freaked out about going anywhere in the car.


2 comments:

  1. I noticed with glee that my milkweed had some chew holes in it. Flipped it over to see a horde of little caterpillars devouring it! I'm sure now,that it was milkweed tussock moth caterpillars. Thanks for that info!

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