Studies on Pheromones and other Semiochemicals of the African Brown Ear Tick, Rhipicephalus Appendiculatus Neumann

Abstract

Ticks re of great concern all over the world because of the diseases they transmit in livestock resulting in a reduction i n livestock productivity. Studies of pheromones and other semiochemicals of ticks have shown promise for use in integrated pest control strategies. Male Rhipicephalus appendiculatus (Neumann), fed for 8 days, and female ticks, fed for two days, were found to attract both unfed male and female conspecific ticks on rabbits. telltale tick extracts, when placed on rabbits, were found to attract both male and female ticks. The extracts also attracted male and female ticks in T-tube assays. Cattle ear swabs attracted males and females in the T-.tube assays,. However, swabs from the legs, back, perineum and belly did not attract the adults, nymphs or larvae. Swabs from the ears were found t:o repel the nymphs and larvae. 2,6-dichlorophenol was found to be an attractant for both unfed male and female ticks in a T-tube assay system. and for nymphs and larvae in a Y-tube assay system. Only fed males were attracted to rabbit ears treated with 2,6-dichlorophenpl. Chromatographic analyses revealed the presence of 2,6-dichlorophenol in both unfed,. and fed male and female ticks. However, fed female ticks contained more of the phenol than fed male ticks. Mixtures of 2,6-dichlorophenol and ear swabs, and of ear swabs and male tick extracts, produced inhibitory responses from the adult: ticks , while responses from nymphs and larvae were inhibited by a mixture of ear swabs and 2,6-dichlorophenol. A mixture of 2,6-dichlorophenol and male tick extract. did not affect responses from the adult ticks.