A Two-Year Study of Ticks Infesting Camels in Al-Kharj in Saudi Arabia

The weather in Al-Kharj area was characterized by a wide range of relative humidity 17-85% and temperature 10.4-35.6oC and little or no rainfall (0.0-21.0 mm) throughout 1990 and 1991. Of the ticks collected monthly during the study period from 10 camels, the desert-adapted Hyalomma dromedarii formed 84.65 and 80.95 %, H. impeltatum formed 11.95 and 12.55%, H. anatolicum excavatum formed 2.47 and 4.43%, H. a. anatolicum formed 0.85 and 1.82%, H. marginatum rufipes formed 0.08 and 0.19% and Rhipicephalus turanicus formed 0.0 and 0.06%, respectively. Greater numbers of ticks were collected in 1991 than 1990. Camel infestation with H. dromedarii ranged between 40 and 100% in both years with infestation peaks in August in 1990 (18.5 ticks/host) and in May, August, October and December in 1991 (17.2-23.7 ticks/host). Usually males outnumbered females during both years (1.1:1-5.5:1 and 1.2:1-9.0:1, respectively). Nymphal H. dromedarii infested camels for 6-8 months with highest infestation rate in August in both years (4.1-4.5 ticks/host). Camel infestation with H. impeltatum ranged between 10 and 90% with infestation peaks in June of 1990 (3.8 ticks/host) and in May of 1991 (6.4 ticks/host). The change in infestation with both species was not correlated with temperature, relative humidity or rainfall. Control measures against both species on camels will probably be more effective during peak infestation.