Question
How do I know if the brown spots on my St. Augustine grass are chinch bugs or fungus?  Thanks, Michelle (Sarasota)

Answer
You can eliminate bugs by doing a 2x2x2 'soap flush' on random spots on the lawn. Mix 2 ounces of dishwashing liquid in 2 gallons of water and pour it slowly over 2 sq. ft. of lawn. Choose an area that includes both brown and green grass. In a few minutes, all the bugs in the area will try to come to the surface. Some will be harmful, others not. Identify the chinch bugs and if there are more than 20 per sq. ft., then you should apply some control measure. Count both the adults (black) and the nymphs (red!) for this exercise.
There are other harmful turf insects like army worm etc. If no harmful insect is present, then you might have a fungus or environmental problem (dog urine, oil spill).