White Grubs

If you plan to compost, you can’t be bug shy. It’s always amazing who and what shows up to help break down organic matter. One common creature is the white grub, an especially nasty-looking and ugly larvae. Despite their appearance, they’re not all bad.

If you plan to compost, you can’t be bug shy. It’s always amazing who and what shows up to help break down organic matter. One common creature is the white grub, an especially nasty-looking and ugly larvae. Despite their appearance, they’re not all bad.

White grubs are the larvae of the June bug. Those are the shiny flying beetles that emerge at the beginning of summer. Since the beetle larvae needs food, warmth and shelter for the winter, loving beetle moms lay their eggs in a compost heap so their babies will be well provided for until it’s time for their metamorphosis. While living in the compost, white grubs eat decaying organic matter, contributing to the decomposing process.

Recognize white grubs by their shiny, iridescent white bodies, which you’ll generally find coiled up somewhere in the middle of your compost bin. The best term I’ve heard to describe them is “compost shrimp,” and they are sort of shrimp-ish. They don’t move much, prefer to be buried and have six tiny legs in front under where their mouth must be. Are they slimy? I don’t know. I don’t touch them with my hands. When sifting my compost, I pick the white grubs from the good stuff with a trowel or gloved hands and toss them back into the compost bin with the matter that still needs to break down.

All in all, white grubs aren’t harmful to compost. If you see them, the biggest concern should be the June bugs that will eventually develop. Beetles will eat plant leaves or whatever they can get near. While in the larvae stage, white grubs eat mainly decomposing matter so they aren’t even that bad if you find them in the garden. When they run out of decaying stuff to dine on they will try to eat roots, mainly from grain and grass crops, so corn and lawns could be at risk. I would never add them to my garden, but I don’t have a problem with them in the compost bin (unless I have to look at them.)

If you don’t want white grubs in your compost, pick them out and place in a bucket for birds to eat. Our feathered friends love a fresh “compost shrimp” dinner!