Testing for Insects
In addition to the time-honored method of parting the grass and looking around, the following techniques will expose damaging insects in your lawn.
Soap Drench: Use to flush out sod webworms, armyworms, mole crickets, and caterpillars. Mix 5- to 6-tablespoons of dishwashing liquid in a 2-gallon sprinkling can full of water, and drench 4-square feet of lawn with the solution. Observe the area for three minutes, counting the number of bugs that emerge.
Water Flotation Test: Use for chinch bugs. Cut off both ends of a 2- to 3-pound coffee can, and push it 2- or 3-inches into the soil at the margin of a yellowed area of grass. Fill the can with water, and maintain its level above the grass surface for five minutes as you watch for chinch bugs to float to the top.
Sod Lift: Use for grubs, billbugs, and rose chafer larvae. Using a spade cut three sides of a 1-footsquare piece of sod about 2-inches deep, and lay the sod flap back. If grass roots are chewed off, sift through the top several inches of soil to count larvae. Replace the sod and water well.