Cuticular composition: An alternative taxonomic approach to differentiate between Argas arboreus and Argas persicus ticks (Acari: Argasidae).

Argas arboreus and A. persicus are blood sucking ectoparasites on domestic birds in Egypt. They cause anemia in birds, in addition to transmitting a variety of pathogens that leads to economical loss in the poultry industry. It is difficult for non-taxonomists to differentiate between these species because of minor morphological characters. Therefore, it is very important to identify tick species for developing a suitable strategy to reduce risks to poultry wealth. This study characterized the female cuticular hydrocarbons of two Argas species using gas chromatography-mass spectrometry. Sixty different hydrocarbons were exclusively identified in A. arboureus, whereas only 51 in A. persicus. Some of the hydrocarbon compounds were stage-specific ones that differentiate between two species. Others shared between all feeding stages of both species that improved they are closely related ones. Genetic variability recorded its maximum value between unfed stages of the two species, and similarity reached only 25 %. The present study provides the first chemotaxonomic data to differentiate between two closely related Argas species according to their cuticular hydrocarbons. Therefore, hydrocarbon composition seems to be a promising tool available as a taxonomic character, in addition improved that feeding stage was the susceptible one to be controlled.