QuestionQUESTION: I have kentucky blue grass, and it's grown from seed in our yard. Usually at this time of year we start seeing yellow spots, which we though were due to the dryness, and tried more deep watering. Since last year we've developed way more weeds and clover. This year it's been unusually rainy for our area, and not as hot. A neighbor told us we had bilbugs, due to the large yellow patches, and after we pulled up the grass to see the roots were mostly missing. This year we've fertilized, sprayed for weeds, then one month later, did weed and feed, and one week later, sprayed for weeds again, since the sprinklers came on after we put down the weed and feed. We also just recently sprayed lawn for bugs. Did we kill our lawn with chemicals? We water around once every 2-3 days, pretty deep. Why is half our lawn yellow?
ANSWER: You may well have billbugs if you can pull up tufts of grass with ease; you should be able to see the adult beetles if the damage is as severe as you say. That being the case, an insecticde is needed. You have applied enough weedkiller to take care of the weeds; the fact that they are still there means that the wrong chemical may have been used or applied at the wrong rate. Weedkillers are highly "designed chemicals" which are quite effective. It is our responsibility to choose the correct chemical for the problem at hand and to apply it in acccording to the label directions.
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QUESTION: how do we see the bugs? I have just pulled up the grass in handfuls here and there--do i have to dig up the dirt to check? how long does the grass take to revive if we do kill the bugs? How do we know they are gone?
Answer The following is a quote from a document. The full text can be found at:
http://bugs.ufl.edu/creatures/orn/turf/hunting_billbug.htm
"To inspect for billbugs or grubs, cut three sides of a one foot square piece of sod about two inches deep with a spade under the sod and lay it back. See if the grass roots are chewed off and sift through the soil to determine if larvae are present. Replace the strip of sod. Inspect several areas in the lawn. As a rule of thumb, if an average of ten billbugs is found per square foot, apply an insecticide."
