John F. Carroll

Effects of Tick Control by Acaricide Self-Treatment of White-Tailed Deer on Host-Seeking Tick Infection Prevalence and Entomologic Risk for Ixodes scapularis-Borne Pathogens

We evaluated the effects of tick control by acaricide self-treatment of white-tailed deer on the infection prevalence and entomologic risk for three Ixodes scapularis-borne bacteria in host-seeking ticks. Ticks were collected from vegetation in areas treated with the 4-Poster device and from control areas over a 6-year period in five geographically diverse study locations in the Northeastern United States and tested for infection with two known agents of human disease, Borrelia burgdorferi and Anaplasma phagocytophilum, and for a novel relapsing fever-group spirochete related to Borrelia miyamotoi. Overall, 38.2% of adults and 12.5% of nymphs were infected with B. burgdorferi; 8.5% of adults and 4.2% of nymphs were infected with A. phagocytophilum; and 1.9% of adults and 0.8% of nymphs were infected with B. miyamotoi. In most cases, treatment with the 4-Poster device was not associated with changes in the prevalence of infection with any of these three microorganisms among nymphal or adult ticks. However, the density of nymphs infected with B. burgdorferi, and consequently the entomologic risk for Lyme disease, was reduced overall by 68% in treated areas compared to control areas among the five study sites at the end of the study. The frequency of bacterial coinfections in ticks was generally equal to the product of the proportion of ticks infected with a single bacterium, indicating that enzootic maintenance of these pathogens is independent. We conclude that controlling ticks on deer by self-application of acaricide results in an overall decrease in the human risk for exposure to these three bacterial agents, which is due solely to a reduction in tick density.

The United States Department of Agriculture's Northeast Area-Wide Tick Control Project: Summary and Conclusions

From 1997 to 2002, the U.S. Department of Agricultures Northeast Area-wide Tick Control Project used acaricide-treated 4-Poster Deer Treatment Bait Stations in five eastern states to control ticks feeding on white-tailed deer. The objectives of this host-targeted technology were to reduce free-living blacklegged (Ixodes scapularis Say) and lone star (Amblyomma americanum [L.]) tick populations and thereby to reduce the risk of tick-borne disease. During 2002 to 2004, treatments were suspended, and tick population recovery rates were assayed. Subsequently, the major factors that influenced variations in efficacy were extrapolated to better understand and improve this technology. Treatments resulted in significant reductions in free-living populations of nymphal blacklegged ticks at six of the seven sites, and lone star ticks were significantly reduced at all three sites where they were present. During the study, maximal significant (p < or = 0.05) efficacies against nymphal blacklegged and lone star ticks at individual sites ranged from 60.0 to 81.7 and 90.9 to 99.5%, respectively. The major environmental factor that reduced efficacy was the occurrence of heavy acorn masts, which provided an alternative food resource for deer. Although the 4-Poster technology requires 1 or more years to show efficacy, this host-targeted intervention was demonstrated to be an efficacious, economical, safe, and environment-friendly alternative to area-wide spraying of acaricide to control free-living populations of these tick species.

Evaluation of the United States Department of Agriculture Northeast Area-wide Tick Control Project by meta-analysis.

As part of the Northeast Area-wide Tick Control Project (NEATCP), meta-analyses were performed using pooled data on the extent of tick-vector control achieved through seven concurrent studies, conducted within five states, using U.S. Department of Agriculture 4-Poster devices to deliver targeted-acaricide to white-tailed deer. Although reductions in the abundance of all life-stages of Ixodes scapularis were the measured outcomes, this study focused on metrics associated with I. scapularis nymphal tick densities as this measure has consistently proven to directly correlate with human risk of acquiring Lyme disease. Since independent tick sampling schemes were undertaken at each of the five environmentally distinct study locations, a meta-analytic approach permitted estimation of a single true control-effect size for each treatment year of the NEATCP. The control-effect is expressed as the annual percent I. scapularis nymphal control most consistent with meta-analysis data for each treatment year. Our meta-analyses indicate that by the sixth treatment year, the NEATCP effectively reduced the relative density of I. scapularis nymphs by 71% on the 5.14 km(2) treatment sites, corresponding to a 71% lower relative entomologic risk index for acquiring Lyme disease.

Anointing Chemicals and Hematophagous Arthropods: Responses by Ticks and Mosquitoes to Citrus (Rutaceae) Peel Exudates and Monoterpene Components

Some birds and mammals roll on or wipe themselves with the fruits or leaves of Citrus spp. or other Rutaceae. These anointing behaviors, as with anointing in general, are thought to function in the topical acquisition of chemicals that deter consumers, including hematophagous arthropods. We measured avoidance and other responses by nymphal lone star ticks (Amblyomma americanum) and adult female yellow fever mosquitoes (Aedes aegypti) to lemon peel exudate and to 24 volatile monoterpenes (racemates and isomers), including hydrocarbons, alcohols, aldehydes, acetates, ketones, and oxides, present in citrus fruits and leaves in order to examine their potential as arthropod deterrents. Ticks allowed to crawl up vertically suspended paper strips onto a chemically treated zone avoided the peel exudate and geraniol, citronellol, citral, carveol, geranyl acetate, α-terpineol, citronellyl acetate, and carvone. Ticks confined in chemically treated paper packets subsequently were impaired in climbing and other behaviors following exposure to the peel exudate and, of the compounds tested, most impaired to carveol. Mosquitoes confined in chambers with chemically treated feeding membranes landed and fed less, and flew more, when exposed to the peel exudate than to controls, and when exposed to aldehydes, oxides, or alcohols versus most hydrocarbons or controls. However, attraction by mosquitoes in an olfactometer was not inhibited by either lemon peel exudate or most of the compounds we tested. Our results support the notion that anointing by vertebrates with citrus-derived chemicals deters ticks. We suggest that some topically applied compounds are converted into more potent arthropod deterrents when oxidized on the integument of anointed animals.

Bioactivity-Guided Investigation of Geranium Essential Oils as Natural Tick Repellents

The evaluation of 10 essential oils of geranium, Pelargonium graveolens (Geraniaceae), were all shown to have repellent activity against nymphs of the medically important lone star tick, Amblyomma americanum (L.). The biological tests were carried out using a vertical filter paper bioassay, where ticks must cross an area of the paper treated with repellent to approach host stimuli. One of the essential oil samples that repelled >90% of the ticks at 0.103 mg/cm(2) was selected for further fractionation studies. The sesquiterpene alcohol, (-)-10-epi-γ-eudesmol, was isolated and identified by spectral methods. (-)-10-epi-γ-Eudesmol at 0.103 and 0.052 mg of compound/cm(2) of filter paper repelled 90 and 73.3% of the ticks, respectively. (-)-10-epi-γ-Eudesmol exhibited similar repellency to the reference standard N,N-diethyl-meta-toluamide (DEET) at concentrations of ≥0.052 mg of compound/cm(2) of filter paper, with (-)-10-epi-γ-eudesmol losing much of its repellency at 0.026 mg of compound/cm(2) and DEET at 0.013 mg of compound/cm(2). Isomenthone and linalool did not repel ticks at the concentrations tested. Most repellents are marketed with much higher concentrations of active ingredient than the concentrations of the natural repellents tested herein; therefore, effective compounds, such as (-)-10-epi-γ-eudesmol, found in geranium oil, have the potential for commercial development.

Control of Ixodes scapularis and Amblyomma americanum through use of the '4-poster' treatment device on deer in Maryland.

Deer self-treatment devices (‘4-posters’) were evaluated for their efficacy in reducing populations of blacklegged ticks, Ixodes scapularis, and lone star ticks, Amblyomma americanum. At each of three locations in Maryland, 25 ‘4-posters’ were operated in study areas of approximately 5.18 km2. Populations of host-seeking ticks were monitored by flagging of treated areas and similar untreated control areas without ‘4-posters.’ From 1998 to 2002 the percent mortalities achieved were 69, 75.8 and 80 at the three study sites infested with I. scapularis nymphs, and 99.5 and 95.3 for A. americanum nymphs at the two sites where this species occurred.

The impact of 4-Poster deer self-treatment devices at three locations in Maryland.

From 1998-2002 twenty-five deer self-treatment devices (4-Posters), using 2% amitraz, were operated at three locations in Maryland to determine their effectiveness in controlling blacklegged ticks, Ixodes scapularis Say, and lone star ticks, Amblyomma americanum (L.). Each treatment site was approximately 518 ha and paired with a similar site lacking 4-Posters. Locations varied in deer density, tick abundance, and land use. Flagging for host-seeking ticks showed declines in tick populations at all treatment sites compared to control sites by the third year. By 2002, control of I. scapularis nymphs attributable to the 4-Poster intervention at the three sites was 69.0%, 75.8%, and 80%. Control of A. americanum nymphs at the two sites where they occurred was 99.5% and 95.3%. In 2003, the first posttreatment year, control of I. scapularis remained around 2001-2002 levels, but by 2004, an upward trend in nymphal numbers was detectable. Populations of A. americanum showed no increase posttreatment. These results demonstrate that control of these tick species is locally possible with 4-Poster intervention.

Sustained Control of Gibson Island, Maryland, Populations of Ixodes scapularis and Amblyomma americanum (Acari: Ixodidae) by Community-Administered 4-Poster Deer Self-Treatment Bait Stations

In 1998, twenty-five 4-Poster deer treatment bait stations were deployed on Gibson Island (GI), Maryland, as part of the U.S. Department of Agriculture (USDA) Northeast Area-Wide Tick Control Project. Treatments concluded in June 2002, having achieved 80% and 99.5% control of blacklegged ticks, Ixodes scapularis, and lone star ticks, Amblyomma americanum, respectively. No area-wide tick control was attempted again on the island until 2003, when 15 Dandux-manufactured 4-Posters were purchased by the GI Corporation and operated until the present. Annual flagging at sites on the island and a similar untreated area on the nearby mainland in May and June from 1998 to 2007 has demonstrated that populations of host-seeking nymphs of both tick species have remained at consistently low levels on the island during GI Corporation administration of the 4-Posters, in spite of 40% fewer 4-Posters and increased deer density during 2003-2007.

Composite scores for concurrent behaviours constructed using canonical discriminant analysis

0003-3472/

Synthesis of acetals and esters of propargyl, propenyl and propyl alcohols and the bioassay of these and related compounds as fumigants against Anastrepha suspensa (Loew) larvae

38.00 The Association for the Study of A doi:10.1016/j.anbehav.2008.12.011 An animal’s response to a given stimulus may be assessed by measuring more than one type of behaviour. For example, in studies of the chemosensory-based preferences of squamate reptiles for prey organisms, both the frequency of tongue flicking, a behaviour linked to vomerolfaction, and the attempted ingestion of prey-scented objects have been measured. Burghardt (1969; cf. Cooper & Burghardt 1990) proposed combining both tongue-flick counts and biting attacks on scent-laden swabs into a composite index, called the tongue flick–attack score, by which overall preferences for prey-derived chemicals could be compared. In Burghardt’s scheme, an attack, which presumably reflects greater interest in prey-derived cues, was arbitrarily accorded a value equal in weight to the highest number of tongue-flicks displayed by any nonattacking subject to any condition, plus the number of seconds in a trial minus the attack latency. If scores were log-transformed, a value of one was added prior to transformation.