LDD (European Gypsy) moth disposal


Hi there: now that I have collected and drowned hundreds of the caterpillars, where do I dump them. Thanks Bayla Hernick


Thank you Bayla for contacting Toronto Master Gardeners about discarding your Lymantria dispar dispar (European Gypsy Moth) caterpillars.  What a great question!   All the sources I’ve reviewed for Lymantria dispar dispar (LDD) caterpillars give great advice on how to trap and drown these horrid pests, but no specific advice on how to dispose of the drowned caterpillars.   Rest assured that once the caterpillars are dead, there is no further damage they can cause to your trees.  They won’t pupate nor reproduce.   However, hundreds of dead rotting caterpillars will smell horrid.  Three options I’d suggest for disposal of large numbers of LDD caterpillars are:

  • Dig a hole and bury them in your garden. They’ll decompose and add nutrients to your soil.
  • Drain out the water and compost them in your backyard composter – assuming your compost breaks down quickly so the smell is manageable.
  • Drain out the water, bag them in a compostable bag, and put them into your Green Bin for City composting pick up.

Unlike the dead caterpillars, properly discarding LDD moth egg masses is very important, as each egg mass can contain 100 – 1,000 eggs.   After being scraped off, egg masses should be soaked in soapy water for 2 days.   Drain the water, seal the egg masses in a plastic bag and dispose them in the garbage.   Don’t scrape them on the ground, or crush and leave them as they’ll survive to hatch next spring.

I read two interesting ways to dispose of Lymantria dispar dispar caterpillars that unfortunately won’t apply to many of us: brush the live caterpillars into a container and feed them to your pond fish or feed them to your chickens.

Good luck and I’m hoping your trees will survive this year’s infestation of LDD moth caterpillars.

Additional resources:

Ontario’s Invasive Species Awareness Program

Toronto Master Gardener Previous Query re: Gypsy Moth

City of Toronto LDD Moth

July 1, 2021