haller’s organ: a taxonomic character for differentiating hyalomma asiaticum and hyalomma anatolicum ticks (acari: ixodidae)

medically and veterinary importance of ticks of the genus of hyalomma through transmission of related diseases is very obvious. the identification and taxonomy of species of this genus always have been controversial. sometimes accuracy of morphological diagnosis of two closely related species hyalomma anatolicum and hyalomma asiaticum which are reported in fauna of iran, is very difficult. the objective of present work was to study morphological characteristics of haller’s organ as a sensory and olfactory organ of ticks for differential identification of both species by scanning electron microscope (sem). tick specimens were collected from araak (markazi province), ghaen (khorasan jonoobi province), bampour and iranshahr (sistan and baluchestan province), qeshm island (hormozgan province), sarakhs (northern khorasan province), khuzestan and lorestan provinces. after diagnosis of male specimens via different systematic references, the haller’s organs were studied by electron microscopy and outcome photos were prepared. the results of photos shown considerable differences  between haller’s organ capsular pattern of h. asiaticum compared to h. anatolicum. it seems that this measure has potential to identify hyalomma species and other ixodids in iran. overall, our results suggested using haler’s organ as a morphological index to separate different hyalomma species.