Insect scouting and wise pesticide usage (05-08-2006)

April showers may bring May flowers, but along with flowers comes a whole host of insects. Not all insects are damaging to our plants, however, and many are considered beneficial and help reduce the numbers of those that are eating on our plants.

Healthy lawns are inhabited by a multitude of beneficial insects, spiders, and other small invertebrates that feed on plant debris, fungi, and other insects. Almost all turfgrass pests have one or more natural enemies that can be important in suppressing their populations. Natural predation is a legitimate explanation why pest outbreaks are more uncommon in low-maintenance turf than in many higher maintained lawns. There are documented cases of outbreaks of Southern chinch bugs on heavily insecticide treated lawns, but not on neighboring untreated lawns where predators were abundant.

Most conventional insecticides are just as toxic to beneficial insects as to the targeted pests. Therefore, when we apply insecticides to our lawns we are most likely destroying the natural enemies of the pest insect as well.

Insecticides should be prudently applied only when and where they are needed. Therefore, good turf management involves integrated pest management (IPM) that provides a more wiser, effective use of pesticides.

Insect scouting is the first step in IPM. Now is the time to begin a weekly routine of getting on your hands and knees to look for signs of insect damage that may reach threshold levels that will require insecticide application. Scouting will entail looking for turf damages as chewed on leaves, stunted turf, sod that is easily pulled from the ground, frass (insect droppings), etc. and also looking for the insects themselves both in the turf canopy and just below the soil surface.

Published May 8, 2006

Dr. Wayne Wells is an Extension Professor and Turfgrass Specialist. His mailing address is Department of Plant and Soil Sciences, Mail Stop 9555, Mississippi State, MS 39762. wwells@ext.msstate.edu