Meridian 25WG Insecticide could be toxic to beneficial insects such as earthworms.
Depending on what you are using Meridian 25WG Insecticide to treat for you will use this product as follows:
Turfgrass: 3 - 4 oz. (in 1.5 - 5 gallons of water/1000 sqft) per 10,000 sq. ft. (12.7 - 17 oz. per acre)
Foliar 2 - 8.5 oz. per 100 gallons of water
Fire Ants: 1 - 3 oz. per 10 gallons of water
* See product label for complete application instructions