Research Priorities in California Western Region IPM Ant Workshop

Urban Pest Ants of California* Argentine ant25.9% Southern fire ant19.3% Odorous house ant11.1% Carpenter ants9.5% Other species34.2% *Knight, R.L., and M.K. Rust The urban ants of California with distribution notes of imported species. Southwestern Entomologist 15:

Urban Pest Ants of San Diego* Argentine ants84.5% Harvester ants5.2% Crazy ants1.8% Little black ants1.6% Southern fire ants1.3% Velvety tree ants1.0% Other species4.6% *Field, H.C., W.E. Evans, R. Hartley, L.D. Hansen, and J.H. Klotz A survey of structural ant pests in the southwestern USA. Sociobiology 49:

Lloyd Pest Control of San Diego ≈ 35,000 general pest accounts – Major portion of this business is Argentine ant control

Mountain Communities San Bernardino Mts. – No Argentine ants – Other ant pests

Velvety Tree Ants Liometopum luctuosum

Red Imported Fire Ants

Argentine Ants Major priority in CA – Structural Pest Control – Homeowners Major research focus – UCR urban program* *Vega, S.J., and M.K. Rust The Argentine ant – a significant invasive species in agricultural, urban and natural environments. Sociobiology 37: 3-25.

Turning Point for PMP’s Approval in CA – December 10, 2002

Impact on Structural Pest Control Lloyd Pest Control – Callbacks 2002: 60, : 55, : 39,000 – 16,000 fewer – Estimated savings = $500,000.00

Fipronil* Slow-acting Non-repellent Horizontal transfer *Soeprono, A.M., and M.K. Rust Effect of horizontal transfer of barrier insecticides to control Argentine ants. J. Econ. Entomol. 97: *Soeprono, A.M., and M.K. Rust Effect of delayed toxicity of chemical barriers to control Argentine ants. J. Econ. Entomol. 97:

Revolutionized Ant Control Most effective treatment to date in CA – Use pattern (AI) 2003: 13,516 lbs. 2005: 66,678 lbs. Appearance in water runoff from urban areas

Research Priority Preservation of insecticides – Developing control strategies that mitigate runoff without sacrificing efficacy

Evaluating Control Strategies for Argentine Ants Around Homes Methods developed by Mike Rust, whose Laboratory team coordinates the summer ant control program at UCR

Estimating Population Levels of Ants Sugar water consumption over 24 hours – 10 vials near house – 10 vials in yard Reierson et al. 1998* 0.3 mg per visit to calculate average number of ant visits/vial near and away from the house over 24 hours *Monitoring with sugar water to determine the efficacy of treatments to control Argentine ants, Linepithema humile (Mayr): Proc. Natl. Conf. Urban Entomol. 1998, San Diego, CA.

Monitoring Before and after treatments applied Treatments replicated at 5 homes

Standard Treatment with Termidor Backpack sprayer – 3-4 gallons spray 0.06% fipronil – Around perimeter 1 ft. x 1 ft. – Along edges Driveway Sidewalks Other areas

Termidor Spray %97% 81% 65% 77% 35%

Spot Treatment One gallon of Termidor – Only active ant trails Capitalize on horizontal transfer of fipronil

Termidor Spot Treatment % 40% 46% 28%

Talstar Spray (0.06% Bifenthrin) 81% 71% 24% 3-4 gal. spray around perimeter of house + edges of sidewalks, driveway, and other areas ants tend to trail 2007

Research Priority Liquid bait development Field trials – 2006: Gourmet (1% borate) – 2007: Vitis (0.001% imidacloprid)

Liquid Baits Gourmet Vitis 73%83%

Vitis Further evaluations by Lloyd Pest Control – Cost analysis: baits vs. sprays – Potential use by PMP’s

Survey of Homeowners 95% rated the treatments as “very effective” Excellent products and strategies – To ensure future use Use judiciously

2008 Refinements of Spray Applications More target-specific Less likely to runoff – Testing Pin-stream vs. fan spray No spray zones – Within 15 ft. of street – Within 5 ft. of driveway or sidewalks Evaluated for efficacy and runoff

Film production by Cheryl Wilen and Ray Lucas

2009 Long-Term Control Programs With Termidor and Talstar – Two spot applications May and August – Monitor efficacy and runoff

Combination Spot-Spray + Baits

Virtual Baiting by Choe and Rust Bait as an attractant – To lure ants over a fipronil-treated surface Environmentally- friendly, targeted ant control

Goals Preserve the use of fipronil and other compounds in ant control Provide new control strategies with little environmental impact

Evaluate Homeowner Products? Determine how to use most effectively – Home Defense – Liquid borate baits – Cedar mulch – Caulking Homeowners contribute to runoff – Require guidelines for safe and effective use of these products

New Research Initiative Biology and control of velvety tree ants – Liometopum occidentale – Liometopum luctuosum Misidentified as carpenter ants – Excavate wood and insulation – Polymorphic – Mesosoma with smooth even profile – Significance as structural pests unknown

Survey Document status as WDO’s Pest control companies in foothill and mountain communities – Cooperator in San Bernardino Mts. – Laurel Hansen in PNW – Need other cooperators

Survey Samples of ants Location of infestations Damage Treatment strategies – Velveties – Carpenter ants – Odorous house ants – Other species causing problems

Comparative Study Colony dynamics – Colony size? Reported to be large Mark-recapture studies Colony extraction – Aggression tests Define territory Number of satellite nests – Colony multiplication and queen numbers? Budding, mating swarms, or both? If mating flights, when? Mono- or polygyne?

Comparative Study Ecology – Habitat differences L. occidentale: sea level – 4,800 ft. – Deciduous trees L. luctuosum: higher elevation up to 8,000 ft. – Conifers – Areas of overlap Competitive displacement?

Comparative Study – Foraging behavior Foraging rhythms? Diet – Tend hemipterans – Predators – Scavengers

Control Bait development – Granular – Liquids Use choice tests – For control – For monitoring efficacy of treatments Current control methods – Barrier sprays

Conclusion Research priorities – Overall pest status in CA Argentine ants – Urban population in mts. Different set of ants