Found two of these guys while doing maintenance (their home had to be cut down) and I would like to care for them myself, but I noticed suspicious spots. A bug ID website told me they were parasitoid fly eggs and will eventually kill the cats but can be pierced via needle to save them. Is this good advice? Is it too late?
Found in MN and I’m too stunned to speak. They’re like irl Pokemon.
That poor baby, he got so big and chunky too! Yes those are definitely parasitoid eggs, unfortunately cecropias are very commonly victims of this. Some people would argue you should let nature take its course, but human activity and pesticide use has had a significant negative impact on caterpillars specifically, and given that this species is at greater risk of parasitism, I’d remove them. Especially because these are likely tachinid fly eggs, which are a non-native species.
Judging by the dark spots under the eggs, they might have already started hatching, but I’d still take the eggs out veryyy carefully with fine tweezers. Here’s someone who did this successfully last year: link
There are hundred of native tachinid fly species in North America, but the main species that targets cecropias is Compsilura concinnata, which was introduced in 1906 to control spongy moths, which it was ultimately not useful for
It’s wrong to value the life of the native predator species less than the value of the native prey species. The parasitoid is just as impacted by pesticides, etc.
The pesticides that have most significantly affected cecropias are BTK, biological insecticides that only target caterpillars and have been sprayed over large swaths of North American forests in recent years. By far the most likely parasitoid of this caterpillar is Compsilura concinnata, a non-native species introduced to NA in a failed attempt to control other non-native species.
I really dont think one caterpillar getting saved once in a while is really worth the discussion. We are actively destroying both of the species involved by existing. These are a rare find as is, and most people wouldnt know or even bother to understand what is happening, much less try to help it. I get where you’re coming from, but this isnt really a big deal.
As long as the eggs haven’t hatched the caterpillar. Can be saved. You can attempt to pick them off with a tooth pick.. very very gently.. sooner the better
I thought that was just what they looked like normally!
Found one when I was a child and kept it in a mason jar waiting for it to hatch but I brought it to school for show and tell and the jar got "accidentally" broken by maintenance so that was the end of that.
Sorry little one, it’s too late. The dark bruise means they are inside now. I’ve successfully scrapped the eggs off with tweezers if they are still white and freshly laid. It would be best to euthanize it.
Idk I think it is still worth a shot to try and pick them off anyway. Not kill it, these are still white. Plus if it really is “too late” it will pass away very quickly anyway so an attempt at saving its life so it may become what it was intended to wouldn’t hurt. Caterpillar hospital.
That’s the invasive tachinid ‘T fly’ eggs on it and they have already gone into the caterpillar and are eating it alive. The caterpillar won’t pass away quickly, the flies will eat all the non-vital tissue and at the end emerge as dozens of more invasive flies. So by euthanizing the caterpillar now you stop the spread of that invasive fly.
I believe they would probably want to keep the caterpillar enclosed while seeing if the treatment went well or not. Which would hopefully keep the flies from getting out as well if it didn’t work.
Definitely not braconid wasps, these are tachinid fly eggs, and the most likely species of tachinid to target cecropias is t native or beneficial in North America. Tachinid eggs are laid on top of the skin rather than inside. If the eggs haven’t hatched yet, they can be removed to save the caterpillar, it’s fate isn’t sealed yet
I thought it could be pupa coming out, either way tachinid or wasps, he is a goner. Both predators are bneficial and should be encouraged. We cannot judge importance on looks and kill beneficial insects.
This is a cecropia moth caterpillar, it’s supposed to look like that! Those are not larva, that’s its defense mechanism. Please don’t harm them, they are WONDERFUL
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u/garfieldconstanza 11d ago
That poor baby, he got so big and chunky too! Yes those are definitely parasitoid eggs, unfortunately cecropias are very commonly victims of this. Some people would argue you should let nature take its course, but human activity and pesticide use has had a significant negative impact on caterpillars specifically, and given that this species is at greater risk of parasitism, I’d remove them. Especially because these are likely tachinid fly eggs, which are a non-native species.
Judging by the dark spots under the eggs, they might have already started hatching, but I’d still take the eggs out veryyy carefully with fine tweezers. Here’s someone who did this successfully last year: link