Description of the Pest
Southern chinch bug adults are black with whitish wings that fold flat over their body. They are about 0.125 inch (0.3 cm) long. Both long- and short-winged adult forms may be present. Early instar nymphs are bright red but darken to black by the last instar. There are several generations a year, with all life stages present during summer; populations tend to be highest when temperatures are above 90°F. All life stages usually reside in the turfgrass crown and the thatch but can also be observed at the border between damaged and healthy grass. Big-eyed bugs, which are beneficial predators, are similar in appearance to chinch bugs but their large eyes, which are the widest part of their body, distinguish them from chinch bugs.
Susceptible Species
Although bermudagrass, buffalograss, and zoysiagrass are fed upon, only St. Augustinegrass is seriously damaged in California.
Damage
Chinch bugs are active from April through October, especially in full sun. Southern chinch bugs suck sap from nodes and crown of the turfgrass. Yellowish to brownish patches result.
Management
When southern chinch bug occurs in turfgrass, decrease fertilizer rates and maintain adequate moisture. Usually only St. Augustinegrass is significantly damaged by this pest. Treatment may be required if monitoring indicates a need.
Biological Control
Big-eyed bugs, ants, and the fungal insect pathogen Beauveria bassiana are the most important natural enemies of chinch bugs. Maintaining moist conditions favors development of Beauveria.
Cultural Control
If St. Augustinegrass is desirable, select resistant varieties such as Floralawn, Floratam, or FX-10. Thatch removal is important for eliminating conditions favorable for chinch bug survival. Applying the low end of recommended nitrogen slows chinch bug reproduction. Maintaining adequate moisture will increase the tolerance to chinch bug feeding and promotes beneficial fungi that attach chinch bugs.
Monitoring and Treatment Decisions
Use the flotation method or drench test to determine chinch bug presence and population level. For the flotation method, take a 6-inch diameter coffee can, remove top and bottom, and set it 2 to 3 inches into the turfgrass. Fill it with water and wait for 5 to 10 minutes for bugs to float to the surface. The drench test is described in the section MONITORING AND TREATING INSECTS AND MITES. Treat when combined nymph and adult counts average at least 3 per coffee can sample, or 135 per square yard. Mow the lawn and irrigate before treating. After treatment, do not mow or irrigate for at least 24 hours.
| Common name | Amount per 1000 sq ft** | Ag Use REI‡ |
NonAg Use REI‡ |
|
|---|---|---|---|---|
| (Example trade name) | (hours) | (hours) | ||
| Not all registered pesticides are listed. The following are ranked with the pesticides having the greatest IPM value listed first—the most effective and least harmful to natural enemies, honey bees, and the environment are at the top of the table. When choosing a pesticide, consider information relating to air and water quality, resistance management, and the pesticide's properties and application timing. Always read the label of the product being used. | ||||
| A. | CHLORANTRANILIPROLE | |||
| (Acelepryn) | Label rates | 4 | Until dry | |
| (Acelepryn G) | Label rates | 4 | After application complete | |
| MODE-OF-ACTION GROUP NUMBER1: 28 | ||||
| COMMENTS: Make applications when bugs are first encountered and before eggs hatch. | ||||
| B. | CLOTHIANIDIN | |||
| (Arena 50 WDG) | Label rates | 12 | Until dry | |
| (Arena 0.25 G) | Label rates | 12 | When dust has settled | |
| MODE-OF-ACTION GROUP NUMBER1: 4A | ||||
| COMMENTS: Make applications when bugs are first encountered and before eggs hatch. Toxic to bees; do not spray directly or allow to drift onto blooming crops or weeds where bees are foraging. | ||||
| C. | ACEPHATE | |||
| (Orthene Turf, Tree, and Ornamental Spray) | 0.9–1.1 oz | 24 | Until dry | |
| MODE-OF-ACTION GROUP NUMBER1: 1B | ||||
| COMMENTS: For use on golf courses and sod farms only. Nontarget effects likely on other soil-dwelling organisms. Odorous. Highly toxic to bees; do not spray directly or allow to drift onto blooming crops or weeds where bees are foraging. | ||||
| D. | CARBARYL | |||
| (Sevin SL) | Label rates | 12 | Until dry | |
| MODE-OF-ACTION GROUP NUMBER1: 1A | ||||
| COMMENTS: Nontarget effects likely on other soil-dwelling organisms. Highly toxic to bees; do not spray directly or allow to drift onto blooming crops or weeds where bees are foraging. | ||||
| E. | CYFLUTHRIN | |||
| (Tempo 20WP)* | 0.176 oz (5 grams) | — | Until dry | |
| MODE-OF-ACTION GROUP NUMBER1: 3A | ||||
| COMMENTS: Highly toxic to bees; do not spray directly or allow to drift onto blooming crops or weeds where bees are foraging. | ||||
| F. | DELTAMETHRIN | |||
| (DeltaGard G) | 2–3 lb | — | Until dry | |
| MODE-OF-ACTION GROUP NUMBER1: 3A | ||||
| COMMENTS: Not for use on sod farms or in commercial seed production. For best results, irrigate with an adequate quantity of water to thoroughly moisten grass and thatch and to dissolve the granules. | ||||
| G. | PERMETHRIN | |||
| (Astro, etc.) | 0.4–0.8 fl oz | 12 | Until dry | |
| MODE-OF-ACTION GROUP NUMBER1: 3A | ||||
| COMMENTS: Apply using sufficient water to provide adequate coverage. Highly toxic to bees; do not spray directly or allow to drift onto blooming crops or weeds where bees are foraging. | ||||
| H. | BEAUVARIA BASSIANA | |||
| (BotaniGard, Mycotrol) | Label rates | 4 | 4 | |
| ** | Apply in 25 gal water/1000 sq ft |
| * | Permit required from county agricultural commissioner for purchase or use. |
| 1 | Rotate chemicals with a different mode-of-action group number, and do not use products with the same mode-of-action group number more than twice per season to help prevent the development of resistance. For example, the organophosphates have a group number of 1B; chemicals with a 1B group number should be alternated with chemicals that have a group number other than 1B. Mode-of-action group numbers are assigned by IRAC (Insecticide Resistance Action Committee). |
| ‡ | Restricted entry interval (REI) is the number of hours (unless otherwise noted) from treatment until the treated area can be safely entered without protective clothing. Agricultural use applies to sod farms and commercial seed production. |
| — | Indicates use is not listed on label. |