Read and follow label directions to get the chemical into the soil. I would recommend putting granules out on dry lawn and sprays onto wet lawns. Then follow with one-fourth inch of water. Orthene will probably move into the soil faster than Dursban or Diazinon. There are many other available chemicals.
Spittle bugs prefer moist, thatchy, centipede lawns.
Thatch control and proper watering are important in their control. The adults are easy to see. They are brown with two orange stripes in their backs. They hop and fly readily. They feed on hollies.