Description of the Pest
Adult fiery skippers closely resemble butterflies but have a hooked knob at the end of their antennae. They have orange or orange-brown wings and are commonly seen feeding on lantana blossoms. Adult females glue hemispherical eggs singly to the underside of grass leaves. Newly hatched larvae notch leaves. As they grow, they consume entire leaves. The larva is about 1 inch long and has what appears to be an oversized black head, a narrowed "neck" followed by a dark thoracic shield, and a greenish brown body color with a granulated texture. Larvae spin silk shelters in the thatch from the third instar on, and are not readily seen unless flushed out with a drench test.
Susceptible Species
Bermudagrass is preferred by fiery skippers, although they also feed on St. Augustinegrass, bentgrass, and occasionally other turfgrasses.
Damage
Skipper larvae feed from May through September. Damage appears as a 1- or 2-inch diameter round spot from which all the grass has been eaten by a single larva. If there is a large population, then these spots will coalesce into dead patches. Usually damage appears on turfgrass planted near flower beds, where adult skippers feed.
Management
If skipper larvae are damaging turfgrass, dethatch the turfgrass to eliminate larval habitat. If monitoring indicates treatment is warranted, treatment choices include parasitic nematodes and Bacillus thuringiensis (Bt).
Biological Control
Larvae are attacked by parasitic braconid and ichneumonid wasps. The extensive soil or thatch contact of fiery skipper larvae may make Steinernema carpocapsae nematodes a valuable control measure, although this has not been tested. Bacillus thuringiensis subsp. kurstaki (Bt) may also be effective against fiery skipper, although more testing is needed to determine its efficacy for this purpose.
Monitoring and Treatment Decisions
Use the drench test to monitor this pest, see MONITORING AND TREATING INSECTS AND MITES. Five larvae per square yard on bentgrass greens and 15 per square yard in bermudagrass indicate treatment thresholds.
Mow the lawn and irrigate the site before applying insecticide, and do not mow or irrigate the turfgrass for at least 24 hours after treatment unless nematodes were applied, in which case apply a post-treatment irrigation. When Bt is applied, do not irrigate for 2 days after treatment.
| 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. | SPINOSAD | ||||
| (Conserve SC) | Label rates | 4 | Until dry | ||
| MODE-OF-ACTION GROUP NUMBER1: 5 | |||||
| COMMENTS: Toxic to bees; do not spray directly or allow to drift onto blooming crops or weeds where bees are foraging. | |||||
| B. | BACILLUS THURINGIENSIS ssp. KURSTAKI | ||||
| (various products) | Label rates | 4 | Until dry | ||
| MODE-OF-ACTION GROUP NUMBER1: 11A | |||||
| COMMENTS: Breaks down rapidly in sunlight and washes readily off leaves. Do not irrigate for 2 days after treatment. | |||||
| C. | HETERORHABDITIS BACTERIOPHORA | 25–35 million | NA | NA | |
| COMMENTS: Store nematodes properly before use as directed. Apply to warm, moist, but not soggy soil. Several irrigations may be needed during 2 weeks after application to keep soil moist. Apply during the coolest time of day in hot areas. | |||||
| . . . or . . . | |||||
| STEINERNEMA CARPOCAPSAE | 25 million | NA | NA | ||
| COMMENTS: Store nematodes properly before use as directed. Apply to warm, moist, but not soggy soil. Several irrigations may be needed during 2 weeks after application to keep soil moist. Apply during the coolest time of day in hot areas. | |||||
| D. | AZADIRACHTIN | ||||
| (Azatrol, Neemix) | Label rates | 4 | Until dry | ||
| MODE-OF-ACTION GROUP NUMBER1: un | |||||
| COMMENTS: Most effective on young larvae. Can be used on both warm- and cool-season grasses. | |||||
| E. | PYRETHRINS | ||||
| (various products) | Label rates | See label | |||
| MODE-OF-ACTION GROUP NUMBER1: 3A | |||||
| F. | CHLORANTRANILIPROLE | ||||
| (Acelepryn) | Label rates | 4 | Until dry | ||
| (Acelepryn G) | Label rates | 4 | After application complete | ||
| MODE-OF-ACTION GROUP NUMBER1: 28 | |||||
| G. | 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: Toxic to bees; do not spray directly or allow to drift onto blooming crops or weeds where bees are foraging. | |||||
| H. | 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. | |||||
| ** | 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 ("un"= unknown or uncertain mode of action) 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. |