Novel Methods of Hematophagous Arthropod Control

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dc.contributor.advisor D. Wesley Watson, Committee Member en_US
dc.contributor.advisor Christina M. Grozinger, Committee Member en_US
dc.contributor.advisor Charles S. Apperson, Committee Member en_US
dc.contributor.advisor James Harper, Committee Member en_US
dc.contributor.advisor R. Michael Roe, Committee Chair en_US
dc.contributor.author Bissinger, Brooke Witting en_US
dc.date.accessioned 2010-04-02T19:02:55Z
dc.date.available 2010-04-02T19:02:55Z
dc.date.issued 2009-11-24 en_US
dc.identifier.other etd-11042009-091156 en_US
dc.identifier.uri http://www.lib.ncsu.edu/resolver/1840.16/4880
dc.description.abstract Ticks are important vectors of human and animal diseases. One protective measure against ticks is the use of personal arthropod repellents. Here, the history and efficacy of tick repellents, discovery of new repellents, and areas in need of attention such as assay methodology, repellent formulation, and the lack of information about the physiology of repellency are reviewed. Studies were conducted to examine the efficacy of the repellent BioUD with the active ingredient 7.75% 2-undecanone, originally derived from wild tomato plants. BioUD was compared with 7 and 15% deet using arm-in-cage studies against the mosquitoes Aedes aegypti and Ae. albopictus. No differences were found in mean repellency over 6 h after application between BioUD versus 7 and 15% deet for Ae albopictus. For Ae. aegypti, no differences were found over the same time period for 7% deet. Compared to 15% deet, BioUD was less repellent over the 6-h test period. Human subject field trials were conducted in North Carolina and Ontario comparing the repellency of BioUD to products containing 25 and 30% deet. BioUD provided the same repellency or was more efficacious than 25 and 30% deet, respectively. Repellent efficacy of BioUD and 98.1% deet against ticks was examined in the laboratory using a choice test between repellent-treated and control filter paper surfaces for Amblyomma americanum, Dermacentor variabilis and Ixodes scapularis. BioUD provided greater repellency against A. americanum and I. scapularis than deet. No difference was found between BioUD and deet against D. variabilis. In head-to-head assays between BioUD and deet, undiluted and 50% dilutions of BioUD were more repellent than undiluted deet against all three species. A 25% dilution of BioUD was more repellent than deet against A. americanum while no differences were found between a 25% dilution of BioUD and deet against D. variabilis and I. scapularis. Based on regression analysis, the concentration of BioUD required for equivalent repellency to 98.1% deet was 39.5% for D. variabilis and 29.7% for I. scapularis. A log-probit model could not be constructed for A. americanum from the dosages tested. Repellency of BioUD was compared to five repellents against A. americanum and D. variabilis in two-choice bioassays on treated versus untreated cotton cheesecloth. Overall mean percentage repellency against both species was greatest for and did not differ significantly between BioUD and products containing 98.1% deet, 19.6% IR3535, and 30% oil of lemon eucalyptus. Products containing 5 and 15% Picaridin and 0.5% permethrin were also repellent compared to untreated controls but to a lesser degree than BioUD. The four most active repellents were directly compared in head-to-head bioassays. BioUD provided significantly greater overall mean percentage repellency than IR3535 for A. americanum and D. variabilis. BioUD was significantly more repellent than oil of lemon eucalyptus for A. americanum but did not differ significantly in repellency against D. variabilis. No statistically significant difference in overall mean percentage repellency was found between BioUD and deet for A. americanum or D. variabilis. Laboratory trials were also conducted to determine the repellent activity of BioUD against D. variabilis on human skin. BioUD repelled ticks at least 2.5 h after application to human skin. Characterization of the expressed genes in the tick central nervous system could lead to a greater understanding of the control of development and reproduction at the molecular level. A transcriptome to the female D. variabilis synganglion identified 21,119 unique putative gene sequences, of which 7,379 had significant matches to the GenBank nonredundant database. Microarray analysis comparing synganglia from unfed, partially fed, and mated replete females revealed that 121 of these genes were differentially regulated. en_US
dc.rights I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dis sertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to NC State University or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. en_US
dc.subject microarray en_US
dc.subject transcriptome en_US
dc.subject synganglia en_US
dc.subject ticks en_US
dc.subject BioUD en_US
dc.subject deet en_US
dc.subject repellents en_US
dc.subject mosquitoes en_US
dc.title Novel Methods of Hematophagous Arthropod Control en_US
dc.degree.name PhD en_US
dc.degree.level dissertation en_US
dc.degree.discipline Entomology en_US


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