Derivation of an index for assessing the resistance of zebu cattle to Rhipicephalus appendiculatus Neumann (Acarina: Ixodidae)

A quantitative measure for assessing the level of resistance of zebu cattle to Rhipicephalus appendiculatus is discussed. Basic data for the derivation of the mathematical index were from artificial infestation of cattle to adults, nymphs and larvae of the Rusinga Island stock of the tick species. Observed variables were the weights and numbers of the engorged/detached instars.