Fire Ants - Mound Drench Test
Elizabeth "Wizzie" Brown, EA-IPM (Fire Ant Project), Travis County, TX, and Bastiaan "Bart" M. Drees, Director, Texas Imported Fire Ant Research & Management Project
Materials and Methods:
This trial was established, April 21, 2003 (10:00 a.m - 5:45 p.m.), at Hornsby Bend, Center for Environmental Research (2210 South FM 973, Austin, TX 78725). Sixteen plots, each containing 10 red imported fire ant mounds but varying in length, were established. Plot lengths were measured and arrayed from shortest to longest and divided into three replicates (blocks) each containing five plots. Treatments were assigned randomly within each replicate so that the total plot lengths for the three replicates was roughly equal.
Treatments:
1. Untreated control (check) - 1 gal water per ant mound
2. Diatect III Insecticide (for industrial/commercial use only) = Results Fire Ant Control (Diatect International, 875 South Industrial Parkway, Heber City, Utah 84032, Telephone: 800/227-6616; www.diatect.com) CAUTION. pyrethrins 0.20%, piperonil butoxide (PBO) 1.0%, silicon dioxide 82.0%,: Instructions for use - 4 Tablespoons/gal/mound. Note: 1 lb container treated 26.5 mounds.
3. Diatect V Organic Insect Control (Diatect International, 875 South Industrial Parkway, Heber City, Utah 84032, Telephone: 800/227-6616; www.diatect.com) CAUTION. silicon dioxide 82.45%, pyrethrins 0.50%: Instructions for use equivalent to Diatect III Insecticide - 4 Tablespoons/gal/mound.
4. EcoEXEMPT IC Insecticide Concentrate (EcoSMART Technologist, Inc. 318 Seaboard Lane, Suite 202, Franklin, Tennessee 37067; Telephone: 888/326-7233; 615/261-7300; FAX: 615/261-7301). CAUTION. Rosemary Oil 10% (Inert Ingredients: Oil of Wintergreen, Mineral Oil): Instructions for use provided by Gary Ross (Prentiss Inc., 817/263-1799) - Mix 2 oz non-ionic surfactant (e.g., Thoroughbred) per quart EcoEXEMPT IC; apply to red imported fire ant mounds as 1 oz/gal/mound drench.
5. Erath Earth Orange Oil (Erath Earth a Gathering and Holding Co., Rt. 2, Box 111, Hico, TX 76457) Directions for use: 1-2 oz per gallon of water for foliar spray; 6 to 8 oz per gallon of water for soil drench. Applied in similar manner as EcoEXEMPT IC - Mix 2 oz non-ionic surfactant (e.g., Thoroughbred) per quart EcoEXEMPT IC; apply to red imported fire ant mounds as 1 oz/gal/mound drench.
The emulsifier used in treatments 4 and 5 was Thoroughbred Nonionic Organosilicone Surfactant (Estes Inc., Wichita Falls, TX 76303) - proprietary blend of polyalkyeneoxide modified polydimethylsiloxane and nonionic surfactants 99%).
Prior treatment, each mound market with a field flag for treatment was examined for ant activity using the minimal disturbance method whereby a mound is considered to contain an active colony if a dozen or more worker ants emerge en masse following mild disturbance. This assesment was made 4, 7, 14, 30 and 46 days following treatment. On the last evaluation date all imported fire ant mounds were counted within each plot to determine if colonies had migrated into or out of plots of may have moved or "shattered" as a result of treatment. Native ant colonies present in plots were also noted. Data were analyzed using using analysis of variance (ANOVA) and separated using Duncan's Multiple Range Test (DMRT) at P < 0.05 (Microstat, Ecosoft, Inc.).
Results and Discussion
Little rain occurred during the course of this trial (DATA?) Resulting in a steady decline of ant activity as documented in mounds treated with 1 gallon of water drech only on April 21 (Table 1). All treatments significantly reduced active ant mounds in plots relative to the water drench (untreated check) 4, 7 and 30 days following application. At 14 days after treatment, the only treatments which significantly differed from the untreated check plot mound numbers were: 1) Diatec III containing the non-"organic" piperonil butoxide (PBO) synergist; and, 2) Erath Orange Oil emulsified with Thoroughbred nonionic surfactant. Of interest is the "performance trend" for EcoExempt treatment (emulsified rosemary oil). After 4 days of application, all ant activity in treated mounds appeared to be eliminated, only to return in almost half (4/10) of the treated mounds 7 and 14 days later. Plots were sampled again, 46 days following treatment, so that one assessment could be made following a significant rain event. Statistically, results were similar for marked and treated mound data on that date (June 9), although mound numbers continued to decline in all plots due to prevalent hot dry conditions. There were no significant differences between treatments. In contrast to the 30 dat assessment of all ant nests in treatment plots (Table 2), by day 47 no statistical differences occurred for the total number of mounds per plot (untreated check - 3.67; Diatech III (PBO) - 2.0; Diatec V - 1.6; EcoEXEMPT IC 3.67; Erath Orange Oil - 3.67) and only 3 native ant nests were detected, all in one Erath Orange Oil treatment plot.
As a "home recipe," emulsified Erath Orange oil appeared to be a very promising treatment in this demonstration. It is certainly simpler to formulate than a "recipe" found on another orange oil product, Green Sense 100% Citrus Oil (RO, 1651 Wall Street, Garland, TX 75041; www.greensense.net) 100% D-Limonene (Orange Oil): "As a mound drench, mix one-third GreenSense Citrus Oil, one-third Compost Tea and one-third Blackstrap Molasses. Add one cup of this mixture to one gallon of water. Shake well. Pour directly on affected area. Product information: GreenSense 100% citrus oil is extracted from citrus rind. Common uses for citrus oil are as a household solvent or cleaner to replace a wide variety of chemicals. In addition to its effectiveness as a cleaner and low toxicity, it smells great! Citrus oil can also be used as an ingredient in formulations for various home, garden and pet applications." Note: these orange oil products are not sold as pesticide products (labels make no specific claims of insecticidal activity) and they are not registered as pesticides by the Environmental Protection Agency.
Table 1. Reduction of active red imported fire ant mounds from 10 treated in plots of various lengths (3 replicates) treated April 21, 2003, Hornsby Bend Center for Environmental Research, Austin, Texas (Travis County).
-------------Mean no. active mounds/plot*-------------
Treatment Plot length Day4 Day 7 Day 14 Day 30 Day 46
untreated check 104.0 ft. 8.67a 8.00a 7.33a 6.33a 3.33a
Diatech III (PBO) 98.3 1.00b 1.33b 1.67b 1.00b 1.33b
Diatec V 96.0 1.67b 2.33b 4.67ab 2.67b 1.00b
EcoEXEMPT IC 83.7 0.00b 4.00b 4.00ab 1.33b 0.67b
Erath Orange Oil 87.7 1.00b 2.00b 2.00b 0.33b 0.67b
F ratio 0.161 22.485 11.368 4.33 8.487 5.463
P 0.952 0.0002 0.0022 0.0372 0.0056 0.0203
d. f. = 4
Non-replicated treatment:
Anti Fuego 269.0 ft. 6/10 2/10 2/10 1/10 1/10
* Means in columns followed by the same letter are not significantly different using analysis of variance (ANOVA) and separated using Duncan's Multiple Range Test (DMRT) at P < 0.05.
Table 2. Active red imported fire ant mounds and native ant colonies 30 days following April 21, 2003 treatment, Hornsby Bend Center for Environmental Research, Austin, Texas (Travis County).
Total no. ant mounds/plot*
Treatment Fire Ants Native Ants
untreated check 7.00a 0.67ab
Diatech III (PBO) 1.67d 0.33ab
Diatec V 4.67abc 0.00a
EcoEXEMPT IC 7.00ab 0.67ab
Erath Orange Oil 4.00cd 1.67a
F ratio 7.366 2.258
P 0.0086 0.1519
d. f. = 4
Non-replicated treatment:
Anti Fuego 4.0 0.0
* Means in columns followed by the same letter are not significantly different using analysis of variance (ANOVA) and separated using Duncan's Multiple Range Test (DMRT) at P < 0.05.
RAW DATA:
Replicate Plot Length Treatment
1 11 17 4
2 33 1
12 60 3
8 64 5
9 68 2
2 1 72 4
10 75 1
7 76 2
4 97 5
5 100 3
3 3 102 5
15 127 2
14 128 3
13 143 1
6 223 4
Extra plot 16 269 Anti Feugo
Treatments and total plot length for three replicates:
1. untreated check: 251 ft
2. Diatech III: 271
3. Diatec V: 288
4. EcoEXEMPT IC 312
5. Erath Orange Oil 263
Treatment Plots/Reps1-3 Day4 Day 7 Day 14 Day 30 Day 40
untreated check 2,10,13 8,9,9 8,8,8 6,9,7 5,7,7 2,3,5
Diatech III (PBO) 9,7,15 1,1,1 0,1,3 1,0,4 1,0,2 1,1,2
Diatec V 12,5,14 0,0,5 0,2,5 4,3,7 1,1,5 0,1,2
EcoEXEMPT IC 11,1, 6 0,0,0 2,6,4 1,7,4 2,1,1 0,2,0
Erath Orange Oil 8,4,3 1,1,1 2,1,3 1,1,4 0,0,1 0,1,1
Length
1. 33,75,143
2. 68,76,151
3. 60,100,128
4. 17,72, 223
5. 64,97,102