Biological Studies on the Camel Tick Halomna dromedarii, Koch 1844 (Acarlixodidae)

Abstract

The life cycle of the hard tick Hyalomma dromedarii, fed on rabbits, was studied. About 60% of the larvae behave as 3-host ticks and the rest adopted a 2-host type of development. The acquisition of immunity by repetitive infestations with each of the three stages of H. dromedarii ticks was investigated. Successive infestations with adults or nymphs resulted in decline in their engorgement weights. The weight of egg masses and the number of the females that fed successfully were also reduced. Repeated infestation with larval H. dromedarii did not affect the feeding of this stage. The challenge of rabbits previously exposed to H. dromedarii with any of the developmental stages of this tick showed that rabbits sensitized to adults inhibited the immatmes from completing their engorgement. Histopathological examination of the attachment sites of adult H. dromedarii on sensitized and tick naive rabbits revealed that the feeding sites of the former were characterized by epidermal vesiculation and infiltration of mast cells.