The southern chinch bug (Blissus insularis Barbar) is an insect pest of St. Augustine and Zoysia grasses throughout the state of Florida. This insect causes millions of dollars in damage to turfgrasses each year with infestations peaking in July.
The adult female deposits over 250 eggs over her lifetime. Eggs are deposited close to the ground. The eggs hatch in 6-13 days with the eggs hatching during the winter months. The eggs are small and oval-shaped and turn from a cream/whitish color to amber and eventually red before they hatch. The nymphs from the hatch resemble the adult but they will form wings and black bodies as they mature.
The life cycle of an adult chinch bug is unknown but can range from 10-70 days. Adults are about 6mm long.
An infested lawn usually shows up in circular patches of damage in areas which may be water stressed or in direct sunlight. Infestations may be scattered across the lawn. Chinch bugs feed on the grass between the turf thatch and the organic soil level.
To test for chinch bugs, use a piece of PVC pipe or cut the bottom out of a large can and insert the pipe/can into the soil about 3 inches. Continuously fill the pipe/can with water for about five minutes and if chinch bugs are present, they will float to the surface. Test in 3-4 areas along the perimeter of the damaged area. If chinch bugs are present, it is best to treat the areas with a proper insecticide. Several treatments may be needed to eradicate chinch bugs from the lawn over several months.
Lawns damaged by chinch bugs generally have other environmental stressors such as poor root growth, lack of nutrients, and improper irrigation.