Paralyzing a lepidoptera

How do you paralyze a moth or a butterfly without killing them?

It depends on the purpose. There are different degrees of cruelty involved. Why do you want to?

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For my thesis, im gonna photograph them

If you just need to make them temporarily inactive, a period in the fridge would probably do it, depending what temperatures they are used to.


This leads to death in amphibians, it may well be survivable for insects but I do not know for sure

Also do not use a freezer, and make sure the fridge doesn’t get below freezing, this will kill, you want to replicate early morning cool weather where insects move slow, not freeze them.

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I’ll second @jhbratton that the easiest trick is to just put them in the fridge for an hour or so. A faster technique is to blast them with a little CO2 gas, though they’ll wake up faster. Don’t release them into the wild until they’ll fully functional again (story: when I was doing a mark-resighting study on flies, we once released a still-groggy fly and the ants got it before it could fly away.) But yes a temporary knock-out is usually survivable-- I’ve recorded marked individuals flying weeks later. Fridge time can be recoverable too, though I assume it depends on the species and what they’re adapted to (i.e., I wouldn’t assume a temperate zone species has the same tolerances as a hot desert or tropical forest species).


I’ve been wondering about using CO2 cartridges as a portable option for rendering hymenopterans temporarily docile in order to take photos in the field. Carrying a picnic ice pack for chilling them doesn’t seem very feasible on hot summer days.

There was a recent article about using a sodastream for this purpose:


Putting most temperate amphibians in a fridge/cooler for under an hour won’t kill them. I’ve done this often for research. Many amphibians can be transported in coolers with ice (though not “on ice”) for several days if necessary. This is true even of some subtropical species (I have personal experience with Cuban treefrogs). The fridge is survivable for most temperate insects and maybe tropical - I don’t have personal experience with those, but have heard of it being done at field stations, though I don’t know the length of time. Heck, some insects can survive the freezer for up to a few days (true of fire ants at least).


temporary immobilisation, not permanent paralysis intended @ruca ?