Novel field assays and the comparative repellency of BioUD®, DEET and permethrin against Amblyomma americanum

Abstract

Two new field bioassay methods were developed to compare the repellent activity of BioUD(®) (containing 7.75% 2-undecanone), 98.1% DEET and 0.5% permethrin against natural populations of nymphal Amblyomma americanum (L.) (Acari: Ixodidae). In a cloth sheet assay, pieces of material measuring 41 × 58 cm, separately treated with one of the test materials or the appropriate solvent carrier, were placed at random on the ground and baited with dry ice for 1 h. Mean numbers of ticks on repellent-treated sheets were significantly lower than on control sheets. There was no significant difference in the number of ticks collected between sheets treated with BioUD(®) and those treated with DEET. However, significantly fewer ticks were found on sheets treated with BioUD(®) or DEET than on permethrin-treated sheets. In a sock test, over-the-calf tube socks were treated with one of the test materials or the appropriate solvent carrier. Human volunteers wore a repellent-treated and a corresponding carrier-treated sock on either leg and walked randomly over an area of approximately 4000 m(2) for 15 min. Significantly fewer ticks were collected from socks treated with BioUD(®) or DEET than from socks treated with the carrier and there was no significant difference in repellency between these two agents. No difference in the mean number of ticks collected was found between permethrin-treated and corresponding carrier-treated socks. To examine the mechanism of repellency of BioUD(®) , a four-choice olfactometer was used to assess spatial repellency against adult A. americanum. As expected in the absence of a repellent, when all choices were represented by water-treated filter paper, ticks were equally distributed among the choices. When one choice consisted of BioUD(®) -treated filter paper and the remaining choices of water-treated paper, the distribution of ticks on the repellent-treated paper was significantly lower than might be expected to occur by chance, suggesting that repellency is at least partly achieved by an olfactory mechanism.

Acarine attractants: Chemoreception, bioassay, chemistry and control

“…The ideal would be to have a laboratory assay system that would be a certain mimic of uses in the field. Bissinger et al [41] for example, found an excellent correlation between tick Petri dish repellency assays and human subject tests in the field for two commercial products, DEET and BioUD. They concluded, at least for these two products that the laboratory assay was an acceptable predictor of their practical use in the field.…”

“…This basic design can easily determine if a chemical can function as an attractant in field applications. By examining capture rates over time, information is obtained about the duration of attractant activity [41,42]. While on the surface, such an assay may seem simple to conduct, the placement of treatments and controls can be problematic because acarine populations are not always evenly distributed in the landscape.…”

What Do We Need to Know About Disease Ecology to Prevent Lyme Disease in the Northeastern United States?: Table 1.

“…The evidence for repellent useÑ one of the most commonly promoted methods of personal protection against tick bitesÑto lower the risk of B. burgdorferi infection is limited (Klein et al 1996, Smith et al 2001, Vazquez et al 2008, Connally et al 2009, Bissinger et al 2011. There is no question that I. scapularis is repelled from skin and clothing by commercially available repellents containing DEET and other active ingredients (Carroll et al 2004, Environmental Protection Agency 2010.…”

Laboratory and field evaluation of brown dog tick behavioral responses to potential semiochemicals

“…The ticks were prevented from entering the mixing chamber by metal mesh on the upwind end of the olfactometers. All airflow rates were 50 mL/min (Bissinger et al, 2011) and verified between each assay using a mass flow meter (AALBORG ® GFM 171, Orangeburg, NY). Humidity in the air flow was routinely measured at the stem of the olfactometer using a data logger with an external probe sensor (U14-002, HOBO, Onset Computer Corporation, Bourne, MA).…”