Certain Mexican strains of Boophilus microplus (Corrales, C; San Felipe, S) with extremely high resistance to pyrethroid acaricides have a single point mutation in their sodium channel gene. Another Mexican strain (Coatzacoalcos, Cz) has a moderate level of resistance to pyrethroids and a point mutation in an esterase gene has been found in this strain. The mutation in the tick sodium channel gene does not involve a restriction endonuclease cleavage site and is therefore not possible to detect with conventional restriction fragment length polymorphism (RFLP) analysis. In contrast, the mutation in the esterase gene creates a restriction site (EcoRI) not found in the wild type gene. We have developed polymerase chain reaction (PCR)-based methods to detect the presence of these mutations in tick larvae. These methods are highly sensitive, capable of detecting the mutation in unfed individual larvae. None of individuals from various Australian strains contain these mutations when screened with these methods.
Species 1: Acarina Ixodidae Boophilus microplus (southern cattle tick)
Keywords: PCR, RFLP
The ESA 2001 Annual Meeting - 2001: An Entomological Odyssey of ESA