Repellency and toxicity of mint oil granules to red imported fire ants (Hymenoptera: Formicidae).
Repellency and toxicity of 2% mint oil granules were evaluated against worker red imported fire ants. Solenopsis invicta Buren, in a series of laboratory and field experiments. In continuous exposure experiments, LT50 values ranged from 1.2 h with 164.8 mg/cm2 of 2% mint oil granules to 15.3 h with 1.65 mg/cm2 of granules. LT50 values declined exponentially with increasing rate of mint oil granules. Limited exposure to 164.8 mg/cm2 mint oil granules resulted in > 50% knock down (KD) after 30 min; however, there was no KD at 15 min. Twenty-four hour mortality increased linearly with increasing exposure time. Mean repellency of worker red imported fire ants ranged from 49.2 +/- 5.4% for 0 mg/cm2 (untreated control) of mint oil granules at 30 min to 100% for 147.8 mg/cm2 of mint oil granules at 3 h. Repellency increased with increasing milligrams per square centimeter of mint oil granules and exposure time. In field tests, 100% of mounds opened and treated with mint oil granules were abandoned 5 d after treatment and ants had relocated or formed satellite mounds by 2 d after treatment. Unopened mounds treated topically with mint oil granules were not abandoned, but ants formed satellite mounds 2 d after treatment. Mint oil granules could provide another tool for red imported fire ant integrated pest management, particularly in situations in which conventional insecticides would be inappropriate.
Appel
Arthur C
AC
Department of Entomology and Plant Pathology, Auburn University, Auburn, AL 36849-5413, USA. aappel@acesag.auburn.edu
Gehret
Michael J
MJ
Tanley
Marla J
MJ
D000818:Animals; D001000:Ants; D007302:Insect Repellents / Q000008:administration & dosage*; D007306:Insecticides / Q000008:administration & dosage*; D027541:Mentha / Q000737:chemistry*; D009822:Oils, Volatile / Q000008:administration & dosage; D010938:Plant Oils / Q000008:administration & dosage*
D007302:Insect Repellents; D007306:Insecticides; D009822:Oils, Volatile; D010938:Plant Oils