on Rhipicephalus sanguineus (Latreille, 1806) (Acari: Ixodidae)

Abstract

A study was undertaken on the ovicidal and larval repellent activity of Tagetes erecta leaf and flower extracts on Rhipicephalus sanguineus (Latreille, 1806), an important tick species in the world from an economic and medical point of view. Ethanol and methanol extracted plant products tested against the eggs and larvae of R. sanguineus indicated that the ethanol extract of flower had maximum ovicidal activity (86.1%), followed by the ethanol extract of leaf (75%) at 25 mg ml-1 concentration. In all analyses, the homogeneity of variance was significant. The probit analysis clearly indicated that the ethanol extract of the flower has a higher ability to kill the eggs. In the case of larval repellency tested, both extracts of leaf showed the highest repellency (83%) at 2.5 mg ml-1. Significant tick repellency (> 90%) was found in both methanol and ethanol extracts of flower at 2.5 mg ml-1. GC-MS analysis of extracts revealed the presence of bioactive insecticidal compounds such as yangambin, cyclohexane and neophytadine.