Turfgrass-Billbug

Includes
Bluegrass billbug (Sphenophorus parvulus)
Denver billbug (S. cicatristriatus)

Hunting billbug (S. venatus)

Phoenician billbug (S. phoeniciensis)

Pest description and crop damage Adults are about 0.375 inch long, black, with a distinct snout. They lay eggs in late spring. Larvae are white with a brown head, and about 0.25 inch long when mature. Larvae generally reach damaging size by midsummer. Larvae feed on grass roots, cutting them off. Damage often shows up as irregular patches of drought-stressed turf. Kentucky bluegrass most commonly is attacked by billbug larvae. However, tall fescue, perennial rye, and chewings fescue and annual bluegrass are also susceptible. Billbugs cause problems mainly in eastern Oregon, central Washington and Idaho, especially around Ontario-Baker City and Boise-Twin Falls, and also occasionally from La Grande into the Columbia Gorge. More recently modest billbug damage has been observed in the Portland area near Tualatin and also in western Washington near Seattle. The species involved have not yet been identified. The Denver billbug appears to be primarily located in eastern Idaho.

Biology and life history Bluegrass billbugs overwinter as adults. Eggs are laid on grass stems in May or June and hatch in about 2 weeks. As the larvae mature, they move from the crown of the plant deeper into the soil where they feed on roots. There is one generation per year. The Denver and hunting billbugs have a similar life cycle but may lay eggs for a longer period of time resulting in larvae that overwinter in the soil. Damage from these species can occur much earlier in spring than damage from bluegrass billbug. Perennial ryegrasses, fine fescues, and tall fescues with high levels of endophytic fungi are resistant to billbugs.

Management-biological control

  • beneficial nematodes-Read label carefully for application procedures, timing and appropriate soil temperatures for best efficacy.

Management-chemical control: HOME USE

Treat the entire lawn, not just affected areas. Spring applications when adults first become active may prevent larval populations from building to damaging levels. Do not permit children or pets on the treated lawn until it has been watered to wash the insecticide into the turf and the grass is completely dry. Most insecticides are toxic to bees exposed to direct treatment or to residues on blooming weeds/ flowers in lawns: mow and remove clippings prior to applying insecticides.

  • azadirachtin (as a mix with pyrethrinsl)-Some formulations are OMRI-listed for organic use.
  • bifenthrin (may be a mix with other active ingredients)
  • carbaryl
  • chlorantraniliprole
  • deltamethrin
  • fenvalerate
  • gamma-cyhalothrin
  • imidacloprid
  • lambda-cyhalothrin
  • permethrin
  • plant essential oils (clove, mint, peppermint, etc.)-Some formulations are OMRI-listed for organic use.

Management-chemical control: COMMERCIAL USE

Treat the entire turfgrass stand, not just affected areas. Spring applications when adults first become active may prevent larval populations from building to damaging levels. Do not permit children or pets on the treated turfgrass until it has been watered to wash the insecticide into the turf and the grass is completely dry. Most insecticides are toxic to bees exposed to direct treatment or to residues on blooming weeds/ flowers in lawns: mow and remove clippings prior to applying insecticides.

  • azadiractin (Azaguard Botanical Insecticide/Nematicide, Neemix 4.5 IGR)-some formulations are OMRI-listed for organic use.
  • Beauvaria bassiana GHA (Botanigard ES, Botanigard 22WP)-Some formulations are OMRI-listed for organic use.
  • beta-cyfluthrin (Tempo SC Ultra Insecticide
  • bifenthrin (Talstar S, Select Insecticide) at 0.05 to 0.1 lb ai/a. PHI 30 days. REI 12 hr. Bifenthrin is highly toxic to bees and other pollinators exposed to direct treatment or residues on blooming crops or weeds. Do not apply bifenthrin or allow it to drift to blooming crops or weeds if bees or other pollinating insects are foraging in the treatment area. Extremely toxic to fish and aquatic invertebrates. Do not apply if rain is expected within 24 hr or whatever time is necessary for product to dry
  • bifenthrin + imidacloprid (Allectus G Insecticide, Atera 2+1 SC Insecticide)
  • carbaryl (Sevin SL Carbaryl Insecticide)
  • chlorantraniliprole (Acelepryn Insecticide, Acelepryn G Insecticide)-For larvae at 0.1 to 0.2 ai lb/a. Max rate per treatment 0.25 lb ai/a and maximum 0.5 lb ai/a per year in broadcast applications in turf.
  • chlorpyrifos (Andersons Golf Products Insecticide III, Dursban Pro) at 0.22 to 0.044 lb ai/1,000 sq ft. For adults. RESTRICTED USE IN OREGON.
  • clothianidin (Arena 0.25G Insecticide, Arena, 50 WG Insecticide, Arena 50 WDG Insecticide)-For adults or larvae. Note: Neonicotinoid pesticides have been banned from use on public properties in some towns and counties (check with local authorities).
  • clothianidin + bifenthrin (Aloft GC G Insecticide, Aloft GC SC Insecticide, Aloft LC G Insecticide, Aloft LC SC Insecticide)-Restricted use.
  • cyfluthrin (Tempo WP Insecticide, Tempo 20WP Golf Course Insecticide in WSP)-For adults.
  • deltamethrin (Deltagard G Insecticide, D-Fense SC Insecticide)-For adults.
  • dinotefuran (Zylam)-Note: Neonicotinoid pesticides have been banned from use on public properties in some towns and counties (check with local authorities).
  • esfenvalerate + prallethrin + piperonyl butoxide (Onslaught FastCap Spider and Scorpion Insecticide)
  • imidacloprid (Mallet 2F Insecticide, several other trade names)-For larvae. Note: Neonicotinoid pesticides have been banned from use on public properties in some towns and counties (check with local authorities).
  • gamma-cyhalothrin (Scion Insecticide)
  • lambda-cyhalothrin (Scimitar)-For adults. 10 fl oz/a, 0.034 lb to 0.068 lb ai/a. Apply at 7-day intervals if treatment is necessary. Do not apply more than 0.36 lb of ai (52.4 fl oz of concentrate) per acre per year.
  • mint oil, geraniol + oil of rosemary (Keyplex Ecotrol Plus Insecticide/Miticide)-OMRI-listed for organic use.
  • permethrin