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Post by eurytides on Feb 27, 2022 16:33:04 GMT -8
I think many people here are probably aware that certain types of caterpillar fluoresce under UV. I recently saw examples of silkmoth eggs and cocoons showing fluorescence under UV. Has anyone used UV flashlights to look for cocoons at night?
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Post by eurytides on Mar 2, 2022 6:22:17 GMT -8
No one? Seems like it would make the search process a lot easier!?
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Post by tv on Mar 2, 2022 8:44:57 GMT -8
I haven't but now I'm tempted because I've never been able to find them.
I have a couple cocoons (empty) that I found a while ago. I checked those with the UV light and they did have some response, but they were old ones that the leaves have fallen off of the outside. I'd be worried that if they were fresh and had leaves on them, that you wouldn't actually see much/any of the silk material because of the leaves.
Do you have a reference/link to the silk moth eggs and cocoons fluorescence?
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Post by eurytides on Mar 2, 2022 8:55:06 GMT -8
Yeah old cocoons may not fluoresce as much. I was also thinking of cocoons that aren’t mostly wrapped up, like cecropia for example. I can find cecropia cocoons in winter but it’s certainly not what I consider an easy task. Frass can also fluoresce, another way to maybe make it easier to find larvae. Here’s my reference, with pictures showing fluorescing larvae, frass, and silk: brianrobin.ca/ultraviolet-lepidoptera/
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Post by kevinkk on Mar 2, 2022 10:21:47 GMT -8
It's an interesting topic, but I am guessing it's not practical, perhaps with stronger UV flashlights being available it could work. All the wild cocoons I've ever found, as well as butterfly pupa, and larva have been simply random chance, unless you happen to be in the middle of an outbreak of Coloradia pandora, or something similar. The geography is going to be a factor, for personal safety if nothing else.
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Post by jshuey on Mar 2, 2022 12:55:21 GMT -8
Never heard of the UV thing. But many cats are un-natural shiny under intense LED light at night - and despite being perfectly camouflaged during the day, look like they are wrapped in colored foil at night. This is used quite a bit in the tropics to find cats.
John
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Post by eurytides on Mar 2, 2022 16:29:08 GMT -8
I have seen people with UV lights in the desert finding scorpions with ease. I don’t see why it would be less practical to use this technique for cocoons.
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Post by wingedwishes on Mar 10, 2022 19:14:33 GMT -8
I find scorpions at night in Belize with a black light and it never crossed my mind to look for cats or cocoons! You can bet I’m going to do that this summer
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Post by wingedwishes on Mar 10, 2022 19:29:29 GMT -8
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Post by eurytides on Mar 11, 2022 15:02:22 GMT -8
I just ordered a fairly powerful UV flashlight (18W). Finding cocoons and larvae should be no different than finding scorpions. I am excited to try it out. Will report back. Light should arrive in a couple of weeks.
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Post by eurytides on Mar 20, 2022 21:13:54 GMT -8
Update. My 365 nm flashlight came today. I tried it on an old cecropia cocoon as well as this season's polyphemus and promethea. None fluoresced. It's possible that they are too old and that freshly spun cocoons in the fall would fluoresce more. Larvae will definitely fluoresce. Let's see if this makes finding caterpillars any easier this summer...
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Post by Paul K on Mar 21, 2022 7:05:54 GMT -8
Update. My 365 nm flashlight came today. I tried it on an old cecropia cocoon as well as this season's polyphemus and promethea. None fluoresced. It's possible that they are too old and that freshly spun cocoons in the fall would fluoresce more. Larvae will definitely fluoresce. Let's see if this makes finding caterpillars any easier this summer... You should try on pupa, remove one from cocoon, if so you could go out hunting for butterflies pupa hanging around.
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Post by eurytides on Mar 21, 2022 7:45:44 GMT -8
I did try it on tiger swallowtail pupae but they did not glow. Maybe fresher ones will, I am not sure. I will try it all summer and see what I can find.
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Post by jshuey on Mar 21, 2022 8:10:30 GMT -8
I did try it on tiger swallowtail pupae but they did not glow. Maybe fresher ones will, I am not sure. I will try it all summer and see what I can find. I've never heard of insects fluorescing - just scorpions. john
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Post by eurytides on Mar 21, 2022 9:08:49 GMT -8
I don’t know about other groups of insects but for leps, numerous species have larvae that fluoresce. Some cool youtube videos demonstrate how one can use this to easily find larvae at night with a UV light.
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