Surface Feeders - Bluegrass Sod Webworm (BSWW)

BLUEGRASS SOD WEBWORM (BSWW)
LARGER SOD WEBWORM (LSWW)
aka: Lawn Moth, Snout Moth
scientific names: Parapediasia teterrella, Pediasia trisecta
Similar species: Additional members of the cool season SWW species - Corn Root Sod Webworm, Sliver Striped Sod Webworm, Stripped Sod Webworm, Vagabond Sod Webworm

FIELD KEYS
Hosts: Bluegrass, fine fescues, bentgrass, ryegrass
Site symptoms: Small areas of thinning turf turn off color and in-crease in size daily. These smaller patches coalesce into larger areas of thinning, brown turf. Birds feed on affected areas leaving peck holes and small gray to tan moths can be seen flying low over turf at dusk.
Plant symptoms: Above-ground plant structures show damage from insect feeding activities and frass or green fecal pellets can be found near the centers of smaller damaged areas.
Site keys: Sunny to transitionally shaded well-managed sites that tend to be on the dry side.

SPECIMEN ID
Immatures are gray, green, or tan segmented worms with black spots on their bodies, tan to black heads, and range from 1/2 to 11/8 inch long when fully grown. Adults are small gray to tan 1/2 to 1-inch long moths with 5/8 to 1 3/8 inch wing spans and have readily visible snoutlike projections from their heads.

SCOUTING TIPS
Although the presence of adults flying low in a characteristic zigzag pattern when disturbed or at dusk is definitive, it may not correlate to treatable larval populations. Once adults have been seen, monitor larval populations with soap or insecticidal flushes beginning about two weeks after peak adult activity. Turf can vary widely in its ability to tolerate higher populations of SWWs, but heat or moisture-stressed sites almost always suffer greater damage. Since grasses are SWW's primary food source and their life cycles are quite short, small populations can rapidly increase over several generations to cause substantial damage.

CONTROL STRATEGIES
Cultural: Manage turf for vigorous growth. Overseed or renovate damaged areas with high-endophyte ryegrass or tall fescue varieties. Small adult populations late in the year usually do not require treatment, but should be monitored the following spring.
Chemical: Where scouting is ongoing, correlate larval population data with observed damage to develop site specific treatment thresholds. If this information is not available, consider control applications once damage has been observed or when populations reach 2-15 larvae per square yard (9 sq ft).

Growth stages: egg - larva (up to ten instars)* - pupa - adult
* - treatable stages

Life cycle: 1 year life cycle (multiple generations)
Sequence: larva - pupa - adult - egg - larva