Jannb PM'd me about this thread and I just was going through my mail and saw the PM now.
We feed out a lot of butterworms here (to our chameleons), and we sell tens of thousands of butterworms to the reptile world and fishing hobbyists (last week alone we shipped out about 38,000 worms) so we have wide experience with this topic.
We import the worms from Chile under the control and guidance of the U.S. Department of Agriculture. We had to get a special license for this. The Dept. of Ag. then issues us special labels for each package, and we ship these labels to the exporter in Chile. The worms are then collected, irradiated, and shipped back. They come into the U.S. in Atlanta and are screened by customs, and the Department of Agriculture, and then forwarded to us. The irradiation is done to sterilize the worms so that, should they grow into adult moths, they will not be able to reproduce and wipe out our crops. Irradiation is a safe and common method that is also used on foods (such as milk and certain cheeses) that humans eat here in the U.S. The irradiation is performed, by appointment, at special approved laboratories in Chile which then have to fill out paperwork which gets submitted to the U.S. Department of Agriculture when the worms enter the U.S. Everyone in the chain has to be licensed and approved. The Dept of Ag. is sort of the ATF of the food world, and butterworms are treated as food. They are actually eaten by the local populace where they are collected. No, I've never tried one (yet).
I have seen butterworm skins come out in poop, looking like "empty" butterworms. This appears to happen with the larger worms. My guess is that after a certain molt the skin has a different make-up that is more difficult to digest. But we have scores of chameleons here and I have only witnessed this about 10 times. In the past I have also seen this happen with silkworms occasionally. I have also had chams experience loose stools when first introduced to silkworms (but then they adjust to them), but have not seen loose stools after eating the butterworms.
If your animal is routinely passing undigested butterworms then I would stop feeding them to it because that can be a sign of food sensitivity.
It appears the larger butterworm is digested best when the skin is "pierced" by chewing or biting. When I feed butterworms to a debilitated animal I cut the worm's skin first. And sometimes I remove the head too (of the worm).
It has been reported to us that Butterworms seem to cause problems with crested gecko skin around the mouth. For that reason we do not recommend butterworms be fed to crested geckos. I have not seen this reaction in our chameleons, anoles, spiny tailed iguana, blue tongued skink, or other gecko species that we have. And they have all eaten regular quantities of butterworms. Our crested geckos are raised on Repashy CGD and dusted crickets- no butterworms for them.
If your animal spits out butterworms or seems to develop a rash around the mouth or defecates whole butterworms I would refrain from feeding that animal butterworms right away. If you purchased the butterworms from us and were absolutely unable to use them you'd likely get a refund.
Syn, would it be possible to reload the photos on that old thread you linked to? it may be helpful to the crested gecko folks here. That was a good thread.
