Pardon this being a bit of a stretch for gardening, it's the closest StackExhange I could think of.

I keep worms for vermicomposting and in addition to food scraps and browns I supplement their diet with a "worm food" product. It's a purchased product which comes as a fairly dry mix of food and I store it in a metal can with a lid since mice have found it delicious.

Today I found it had been infested by moths, so I'm considering if I can kill the moths and feed the rest to the worms. I have enough it would be a bit of a waste to dispose of.

I'm curious if there would be a simple way to kill the moths, larvae, and eggs. Would deep-freezing do the trick? Or even just dumping the food, moths and all, into a new worm bin and covering them with a few inches of the usual wormbin contents?

2 Answers 2


To kill the moth larvae before adding to the compost:

Moisten with water, microwave to boiling point.

Or just freeze. A large amount will need longer in the freezer, the centre is insulated.

When cool give to the worms.

Probably pantry moths.

  • 1
    Thanks; I'll try putting them in the deep freeze for a solid (pun intended) week or so and see if that knocks them out. Microwaving would be an option but might put my marriage or life at risk :-D
    – STW
    Aug 26, 2022 at 21:28

I would recommend attacking the exoskeletons of the moths using a mechanical pesticide. Moths and earth worms are two different species thus are affected by different things. Using food grade diatomaceous earth will reduce the moth population significantly. On the other hand changing the container is really not beneficial being the moth larva are present in your medium. As for deep freezing this probably would do nothing other than putting your worm colony at risk. I would also try to encourage the moths to breed in a different location. To do this blended mixture of lavender, bay leaves, cloves, rosemary, and thyme together and introduce to the worm colony " before the diatomic earth is put down". If the insect is truly a moth then this will encourage the insects to breed elsewhere and not in the worm colony the ones that stay behind will be taken care of by the diatomaceous earth. All around this is the cheapest method I could think of. That is if you have moths but I suspect you have this insect present in your colony Clogmia albipunctata in this case the herb mixture will do very little if anything at all. If you have Clogmia albipunctata, also known as drain flies, then before you put the diatomic earth down spray the medium with Neem oil. I would exercise caution when doing this because too much can harm your worms and not enough will not kill the drain flies.

Worms and Diatomaceous Earth
Drain Flies
Fact Sheet on Neem Oil

  • 3
    ...since the moth-infested worm food is separate from the worms at present, freezing the worm food has no possible effect on the worms. Your answer seems to be entirely focussed on a situation that is not the case in this question of "moths in the worm beds" rather than moths in the worm food that's not in the worm beds, yet.
    – Ecnerwal
    Aug 26, 2022 at 13:10
  • 1
    ^ yes, sorry if I was unclear -- the worm bins are fine and unaffected as far as I'm aware. Just a separate package of worm food has the moths in it.
    – STW
    Aug 26, 2022 at 21:27

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