RESUMO
The western black-legged tick, Ixodes pacificus, is a primary vector of the spirochaete, Borrelia burgdorferi, that causes Lyme disease. We used variation in a 355-bp DNA portion of the mitochondrial cytochrome oxidase III gene to assess the population structure of the tick across its range from British Columbia to southern California and east to Utah. Ixodes pacificus showed considerable haplotype diversity despite low nucleotide diversity. Maximum parsimony and isolation-by-distance analyses revealed little genetic structure except between a geographically isolated Utah locality and all other localities. Loss of mtDNA polymorphism in Utah ticks is consistent with a post-Pleistocene founder event. The pattern of genetic differentiation in the continuous part of the range of Ixodes pacificus reinforces recent recognition of the difficulties involved in using genetic frequency data to infer gene flow and migration.
Assuntos
DNA Mitocondrial/genética , Variação Genética , Ixodes/genética , Animais , Canadá , DNA Mitocondrial/análise , Complexo IV da Cadeia de Transporte de Elétrons/análise , Complexo IV da Cadeia de Transporte de Elétrons/genética , Haplótipos/genética , Filogenia , Estados UnidosRESUMO
Of 12 alarm pheromones assayed in European and Africanized honeybees, nine were found in larger quantities in the Africanized population. Isopentyl and 2-heptanone levels were similar in both; 2-methylbutanol-1 was greater in European workers. These differences were not due to age or geographical location. Significant positive correlations between alarm pheromone levels and defensive behavior, especially numbers of stings, were observed.
