Activity of papaya (Carica papaya) latex on Rhipicephalus microplus (Acari: Ixodidae) under laboratory conditions

Rhipicephalus microplus (Canestrini 1888) causes severe economic losses to the cattle industry in Brazil. Products alternative to chemical acaricides have been investigated for tick control, and the use of plant-derived products may be a promising approach. In the current study, we investigated the activity of the latex of Carica papaya L. fruit on larvae and engorged females of R. microplus. Decreased weight of egg mass was reported from females treated with active papaya latex or denatured latex in relation to their control group treated with distilled water only; however, females treated with the highest active latex concentration had the lowest weight of egg mass compared to the other treatment and control groups. Percent control of ticks treated with active latex ranged from 19.81% (25 mg mL(-1)) to 92.36% (100 mg mL(-1)). In addition, all concentrations of active latex caused significant mean mortality of R. microplus larvae. The present study indicated, for the first time, the acaricidal effect of the proteolytic activity of a plant latex on the tick cuticle. We concluded that active C. papaya latex is a promising candidate for developing a sustainable and ecofriendly bioacaricide to control R. microplus.