Histopathological effects of the fruit extract of Citrullus colocynthis on the ovary of the tick Hyalomma dromedarii.

Hyalomma dromedarii is the predominant tick species parasitizing camels in Egypt which leads to mortalities in young animals that result in economic losses. It can transmit a lot of pathogens to animals and humans, such as the Crimean-Congo hemorrhagic fever virus, the Dhori virus, Kadam virus, Theileria annulata and spotted fever rickettsia. The continuous use of chemical acaricides has negative impact on the environment and almost led to acaricidal resistance, and hence the plant extracts represent alternative methods for controlling ticks.

Acaricidal effect of Citrullus colocynthis fruit extract on the camel tick Hyalomma dromedarii (Koch, 1844).

The hard tick Hyalomma dromedarii is one of the most injurious ectoparasites affecting camels in Egypt and several other areas of the world. Hyalomma dromedarii engorged females were dipped in alcoholic extract of Citrullus colocynthis fruits at concentrations of 25, 50, 100, 200 and 400 mg/mL and then observed over four weeks following treatment. There was a marked increase in dead females following single treatment with the above concentrations, particularly for the two highest which caused ≥ 90% mortality.