The most common problems in this area, in the summer with lawns are Brown Patch and grubs, grasshoppers, crickets and chinch bugs. Brown patch will cause St Augustine grass it to turn brown, wilt and dry up. It turns brown in a circle, growing outward. Brown Patch has a tendency to grow back from the middle of the spot out leaving a round ring. St Augustine grass is better suited for the Gulf Coast. Bermuda, Buffalo and other heat tolerant grasses are better for this climate. The heat of July and August and over watering or following a rainy few days is prime time for Brown Patch to become active. Brown Patch has a tendency to grow in turf which is high in nitrogen or over fertilized. Dead clippings are easy prey for any air borne fungus spores. It is strongly advised that these clippings are bagged during times of the fungus outbreaks. Watering should be done just before or at daybreak - not in the evening or just after dark. Furthermore, be sure your yard drains and does not hold standing water. Your soil to be properly balanced, soil balance is measured using the PH scale. Lawns should have a PH in the 6.5-7.0 range. Since PH fluctuates over the course of a year, it is important that you measure this value at least twice a season. http://www.ces.purdue.edu/extmedia/BP/BP-106-W.pdf
Chinch bugs are a favorite for lawns. They are a small flying insect that will fly up when you drag your foot across the grass. Grubs are also prevalent in watered lawns. If Armadillos are digging in your yard, they are looking for grubs. Grubs eat the roots of grass. You can pick up the grass from the ground, no roots. The same holds true for grasshoppers and cricket larvae. Of course the grasshopper and cricket eat the exposed grass.

TREATMENT
Use a Ph Test Kit or a Ph Soil Probe for this measurement. PH must be in balance if you expect any fungicide treatments to work so before you start doing all kinds of fungicide applications, make sure you know your PH is balanced. A low PH will weaken grass and make it susceptible to drought, disease and insects. Potassium bicarbonate is a good natural fungicide.
Mix permethrin with the insect growth regulator; it leaves a tenacious residual for all insects. An insect growth regulator will not allow the insect to grow to the next stage.
Diatomaceous earth is a holistic treatment for grasshoppers, crickets, fleas and chinch bugs, especially as dry it is. You need to not water for as long as you can. Insects have a body like a shrimp. DE works by absorbing oil from an insect’s body, cutting the joints and allowing body fluids to escape. DE works best when dry; it cakes to a certain degree when wetted.
Eyeglasses are the perfect tool to find that your plants are in stress.