|Mands, V. - UNIV OF EDINBURGH|
|Blackwell, Alison - UNIV OF EDINBURGH|
Submitted to: Medical and Veterinary Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 23, 2004
Publication Date: December 7, 2004
Citation: Mands, V., Kline, D.L., Blackwell, A. 2004. Enhancement of culicoides spp. catches in scotland by odour baits. Medical and Veterinary Entomology. 18:336-342. Interpretive Summary: Biting midges are serious pests of man and his domesticated livestock. They have significant economic impact since their presence often reduces tourism due to their annoying bites, which often produce burning and itching welts. This is particularly true in coastal regions in the United States and the highlands in Scotland, UK. Attempts to control them with traditional methods like low volume spraying of chemical insecticides has not been very successful. In a collaborative research project, scientists from the Center for Tropical Veterinary Medicine, University of Edinburgh, U.K., and the Center for Medical, Agricultural and Veterinary Entomology, Gainesville, FL, have begun investigations on the use of attractant-baited traps as an alternative method of control. The present study investigated the effectiveness of the Mosquito Magnet Pro against the Highland biting midge. Emphasis was placed on the development of an enhanced odor baiting system to improve the specificity of this trap for this species. Of the different baits tested (hexane extracts from hair samples of deer, sheep, calf, water buffalo and pony) only water buffalo extract increased catches significantly. Continued research on new attractants will improve the effectiveness of these traps and that will result in improved population management of the Highland biting midge.
Technical Abstract: Commercial mosquito traps (baited with carbon dioxide and 1-octen-3-ol) were investigated for their effectiveness against the Highland biting midge, Culicoides impunctatus. Given the information available on the host preferences and host-seeking behavior of this species, attempts were also made to enhance the odor baiting system of the trap. Solvent extracts were prepared from hair samples taken from deer, sheep, calf, water buffalo and pony and assayed electrophysiologically (using Culicoides nubeculosus as a model species), behaviorally (in a Y-tube olfactometer) and in the field, through supplementing the standard trap bait. When presented to C. nubeculosus antennae, all extracts gave statistically significant electroantennogram (EAG) responses, with the exception of sheep. Water buffalo extract was most active, with a threshold value of 0.22 g/ml. Behaviorally, C. impunctatus was attracted to the separate extracts in a dose-dependent manner, with deer- and water buffalo extracts showing the highest levels of attractancy. In the field, released at 2.1 mg/day, the water buffalo extract increased catches of C. impunctatus and also, C. pulicaris significantly compared with the standard CO2 plus 1-octen-3-ol bait. These results are discussed in relation to optimising field traps for Culicoides spp. in Scotland.