The southern chinch bug, Blissus insularis, is one of the most important insect pests of St. Augustine-grass in Florida. All varieties of St. Augustine-grass grown today are damaged by the chinch bug. Our current dry and warm conditions here in Central Florida will increase the amount of chinch bug activity and inevitable damage, which will continue until the presence of cooler weather in the fall.
Adult southern chinch bugs are small and slender, 1 /6 to 1 /5 of an inch long, and have black bodies with white wings. Each wing bears a distinctive, triangular black mark. Recently hatched nymphs (immatures) are wingless, yellow or pinkish-red, with a light-colored band across their backs (abdomen).
Drought damage is commonly confused with chinch bug damage because they both cause the grass to turn brown and die. Also, chinch bugs are attracted to drought-stressed areas so you can commonly have both drought damage and chinch bug damage present at the same time. Early symptoms of chinch bugs are irregular patches of dead or stunted grass surrounded by a halo of yellowing, dying grass.
A significant number of live chinch bugs (at least 20 per square foot) will be present where damage is occurring. Chinch bugs are mostly near the soil surface and where the healthy grass meets the yellowing- brown areas. Because chinch bugs are very small and will require a close inspection beneath the grass blades, they are often difficult to find during an inspection.
While chinch bugs can be found causing damage during any time of the year in Central Florida, their damage is most prevalent during the hot, dry weather and often found along the edge of sidewalks and driveways where the soil is usually drier.
Chinch Bug Control
Proper mowing, watering and fertilization will reduce the likelihood of encountering chinch bug activity. However, once chinch bugs begin their damage an insecticide will be needed for control. Chinch bugs can be controlled with granular or liquid insecticide applications.
Chinch bugs can be difficult to control for a couple of reasons. First, most homeowners when making liquid applications don't take the time to apply enough water with the insecticide for an effective treatment. This is because they don't have the equipment that professionals use to apply the insecticide spray mix quickly or they mix incorrectly. The second reason is that we have some chinch bugs have developed resistance to the less expensive and commonly sold insecticides found in garden centers. Professionals have access to more expensive insecticides that are systemic and control chinch bugs when they feed on the grass.
Call today if you suspect that you have chinch bug damage or wish to prevent them. We will be happy to send out a graduate horticulturist to provide you with a free analysis and quote for your lawn. Don't hesitate, your lawn will thank you for it!
Source: University of Florida IFAS