The role of 2,6-dichlorophenol as sex pheromone of the tropical horse tick Anocentor nitens (Acari: Ixodidae).
The objective of this study was to evaluate the role of 2,6-dichlorophenol (2,6-DCP) as sex pheromone of Anocentor nitens. Sex pheromones were extracted by submerging 150 female fed for 6 days in hexane (3 ml) for two hours and sonicating them for 15 min. The extract was analyzed by GC-MS employing the Single Ion Monitoring (SIM) method. Identification of 2,6-DCP was based on the comparison of mass spectra with a computer search using the NIST library and by matching the mass spectrum of the peak at the retention time of 2,6-DCP from extracts and the synthetic product. In an olfactometer, males were released at 2.5 cm from females, control rubber septa and impregnated rubber septa with increasing concentrations of 2,6-DCP (50, 500 and 5000 ng). A higher percentage of orientation and higher frequencies of angles between 0 degrees and 10 degrees were observed for males tested with females than with controls. Attraction of males to dummies impregnated with 2,6-DCP was observed with highest response (100%) at 50 ng. There was a gradual decrease of responsiveness of males with increasing concentration of 2,6-DCP (70 to 75%). This compound stimulated a behavior of mounting and ventral positioning of A. nitens males at the lowest 2,6-DCP concentration whereas dummies impregnated with 2.6-DCP higher than 50 ng concentration inhibited these behaviors. Therefore, we can conclude that 2.6-DCP can elicit the complete behavior sequence of orientation, location, mounting and ventral positioning behaviors and plays a role as an attractant and, as a mounting sex pheromone in A. nitens.
Borges
Lígia M F
LM
Department of Parasitology, UFG. Cx. Postal 131, CEP 74001-970 Goiânia, GO, Brazil.
Eiras
Alvaro Eduardo
AE
Ferri
Pedro Henrique
PH
Lôbo
Ana Cristina Côrtes
AC
D000818:Animals; D002733:Chlorophenols / Q000494:pharmacology*; D005260:Female; D006736:Horses / Q000469:parasitology*; D026863:Ixodidae / Q000187:drug effects* / Q000502:physiology*; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D009812:Odorants; D012724:Sex Attractants / Q000494:pharmacology*; D012726:Sexual Behavior, Animal / Q000187:drug effects
D002733:Chlorophenols; D012724:Sex Attractants; C032729:2,6-dichlorophenol