title: Olfactory and behavioural responses of tabanid horseflies to octenol, phenols and aged horse urine.
abstract: Electrophysiological and behavioural responses of females of two tabanid species, Tabanus bromius L. and Atylotus quadrifarius (Loew) (Diptera: Tabanidae), to ammonia, octenol (1-octen-3-ol), phenols and aged horse urine were compared. Electroantennogram (EAG) responses in both species to octenol, 4-methylphenol (4MP), 3-propylphenol (3PP) and a phenol mixture (4MP and 3PP at a ratio of 16 : 1) increased in a dose-dependent fashion. The most effective stimulus was 4MP and synergism between the two phenols may exist. Aged horse urine also elicited strong EAG responses in both species. Using gas chromatography-mass spectrometry (GC-MS) analysis, we identified 29 compounds in horse urine, which included, in particular, ketones, fatty alcohols and phenols, among which 4MP was the most abundant component (~ 80%). Trapping experiments were carried out using Nzi traps baited with various odours. Octenol and the phenol mixture in combination with ammonia increased catches of tabanids by 1.8-2.8 times relative to ammonia alone. Aged horse urine increased catches of T. bromius and A. quadrifarius by 2.2 and 4.1 times, respectively. The high attractiveness of aged horse urine, especially for A. quadrifarius, is not likely to derive from 4MP alone, but from the mixture of various active compounds used in host location.
authors.affiliation: Unité Mixte de Recherche (UMR) 5175, Centre d'Ecologie Fonctionnelle et Evolutive (CEFE), Université Paul-Valéry (UM3), Montpellier, France.
authors.forename: F
authors.initials: F
authors.lastname: Baldacchino
authors.forename: S
authors.initials: S
authors.lastname: Manon
authors.forename: L
authors.initials: L
authors.lastname: Puech
authors.forename: B
authors.initials: B
authors.lastname: Buatois
authors.forename: L
authors.initials: L
authors.lastname: Dormont
authors.forename: P
authors.initials: P
authors.lastname: Jay-Robert
mesh_terms: D000641:Ammonia / Q000494:pharmacology; D000818:Animals; D057506:Arthropod Antennae / Q000187:drug effects / Q000502:physiology*; D003408:Cresols / Q000494:pharmacology; D004175:Diptera / Q000187:drug effects* / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D055724:Electrophysiological Phenomena; D005260:Female; D005602:France; D008401:Gas Chromatography-Mass Spectrometry; D006736:Horses; D000442:Octanols / Q000494:pharmacology; D010636:Phenols / Q000494:pharmacology; D010675:Pheromones / Q000494:pharmacology*; D013045:Species Specificity; D014556:Urine / Q000737:chemistry
chemical_list: D003408:Cresols; D000442:Octanols; D010636:Phenols; D010675:Pheromones; C010411:insect attractants; C032538:4-cresol; C077057:3-propylphenol; D000641:Ammonia; C038844:1-octen-3-ol
keywords: Baits; Nzi trap; electroantennography; host odours; octenol; urine phenols