Pesticides and Gardening

Certain pesticides approved for general use can severely damage earthworms.

Carbaryl (Sevin), one of the most commonly used home garden chemical pesticides, is deadly to earthworms even at low levels.

Malathion is moderately toxic to worms.

Diazinon has not been shown to be at all harmful to earthworms when used at normal rates.

Solomon, Steve (2011-03-24). Organic Gardener's Composting (p. 95).  . Kindle Edition.