Aim: The major problem of drug intended for tick control is resistance developed to application doses on the hosts. The acaricidal effects of alkaloids from Glaucium flavum and Peganum harmala were evaluated in vitro on adult female of Rhipicephalus sp. collected in naturally infected dogs.

Materials and Methods: The acaricide activities of the both extracts (3.12, 6.2, 12.5, 25 and 50 mg/ml) were evaluated using the adult immersion test, reproductive index and inhibition oviposition. DMSO (1%) and SEB (1?l/ml) were used as a negative and positive control.

Results: The percent mortality caused by the methanolic extracts of both plants varied from 41.66 to 75 %, when tested at concentrations ranging from 3.12 to 50 mg/ml, and significantly different compared to control (p<0.05). Visually hatching of the eggs was completely blocked only by G. flavum with 50 mg/ml; however, other extracts of both plants were partially able to block the hatching. The oviposition and reproductive rate of both plants were concentration dependent in both plants and significantly different (p<0.05) compared to negative control. Also, the extracts of P. harmala seem to be more efficient against Rhipicephalus sp. adults at different concentrations than the extracts G. flavum. The alkaloid extracts of both plants high effects were observed with 6.25 and 50 mg/ml for G. flavum and with 25mg/ml and 50mg/ml for P. harmala.

Conclusion: The total alkaloids extracted from the G. flavum root and P. harmala seed have good acaricidal activities in vitro reducing potentially the egg laying of Rhipicephalus sp. females.