Colbert, D.

Fouché, C.

Marmor, F.

Villalpando, B.

Undetermined

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Section VSoil ArthropodsEVALUATION OF BAIT APPLICATIONS FOR CONTROL OF SOUTHERN FIRE ANTSUNIVERSITY OF CALIFORNIA COOPERATIVE EXTENSIONC. Fouche, D. Colbert, B. Villalpando & F. Marmor (Dupont)University ofCalifornia Cooperative Extension420 South Wilson Way, Stockton CA 95205-6243209/468-2085bfouche@ucdavis.eduThis trial was established at Foiada Farms in Wesly, California in order to evaluate theeffectiveness ofan experimental ant bait with indoxacarb as the active ingredient. Currentlyabamectin (Clinch) and pyriproxyfen(Esteem) are formulated in soy oil on corn meal gritparticles and broadcast for controlofthree ant species in California. The ants targeted are thered imported fire ant Solenopsis invicta, southernfire ant Solenopsis xyloni, and the pavementant Tetramorium caespitum. Currently the RIFA is confined to SouthernCaliforniawith sporaticoutbreaks in Northern California and eradication effortsare led by the California Department ofFoodand Agriculture. The pavement ant, which is native to California, can be responsible forextensive damage to plantsby girlding the roots ofvegetables and sometree species such ascherries and citrus. The primary agricultural use ofthe baits other than eradication efforts oftheRIFA, are the suppression ofsouthern fire ants and pavement ants in nut crops suchas almondsandwalnuts during harvest Nuts cansustain considerable damage while on the ground drying.GoodIPM practices suchas the elimination ofdormant sprays, using BT's for wormcontrol inthe spring rather thanorganophosphates, non-cultivation practices, cover crops and improvedirrigation systems such as micro-sprinklers and drip irrigation, have all served to theadvantageof the ant populations in California agricultural production systems.Treatments were eitherbroadcast with a hand held fertilizer spreader or mounded with atablespoon inthe sample plots onAugust 12, 2003. Plots were 200 feet long by75 feet wide.Fourreplicates were used in a RCB design. Antpopulations were evaluated by placing hotdogpieces ina small vial on the ground for several hours. As the ant activity in the fall decreased,vials were left onthe ground for longer periods inorder to obtain moderate damage intheuntreated control plots. Five vials ofhot dogs were used in eachplot. Sunnyside FarmsChicken & PorkFrank links were used. One-eight of a link containing 140 fat calories/link wasplaced ineach bait station. Vials were frozen overnight, and the ants were counted the next day.The only ant species observed in this trial was the southern fire ant. Final evaluations this yearwere made with almonds by placing 10 nuts in a PVC tube with two 1/4'" holes in the side andleaving it onthe ground for 7 days. Evaluations will be made next spring to determine thelongevity ofthe control. Past experience has shown that fall applications ofbaits will suppressant foraging the next year before the colony has time to increase itspopulation levels.22Treatments Pre-TrtAug 29# Antsper VialSept. 5# Antsper VialSept 12#Antsper VialSep 26# Antsper VialOct 10# Antsper VialOct 10%Damageto DogsUntreated 202.7 a 462.7 c 327.6 b 150.8b 140.3b 4.3bIndoxacarbBroadcast1.5lb/ac273.4 a 15.1a 12.9 a 11.7a 0.0a 0.0aIndoxacarbMound1.5lb/ac256.8 a 0.1a 12.3 a 2.9a 0.0a 0.0aClinchBroadcast1 lb/ac221.2 a 219.4 b 245.8 b 56.2a 20.4a 2.0abOct 24% NutsConsumedOct 24% NutsRejectedOct 22 %ofBermsWith Ant ActivityAfter Hammer Impacts1. Untreated 31.1b 49.0b 65b2. Indoxacarb Broadcast 1.5 lb/ac 0.6a 10.5b 10a3. Indoxacarb Mound 1.5 lb/ac 0.01a 1.3b 0a4. Clinch Broadcast 1 lb/ ac 0.2a 9.0b 50bMeans followed by the same letter are not significantly different (P=0.05DMRT)A reject was any nut that showed signs of insect damage. This is a lower price category for the grower.The indoxacarb ant bait appears to be a very effective. It reduced ant numbers within 10 daysafter the application and lasted for at least 6 weeks. It is not understood why the ants are stillactive in the Clinch treatments as indicated by the hammer impact sample, but apparently not at alevel where they are able to do much damage to the nuts placed on the ground.

Evaluation of bait applications for control of southern fire ants

https://ir.library.oregonstate.edu/downloads/c247dz21h

Evaluation of bait applications for control of southern fire ants

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