Comparison Of The Efficacy Of Melia Volkensii (Gurke) Azadirachtin, Pyrethrum Plant Extracts, Cubex And Steladoner On Cattle Ticks, rhipicephalus Appendiculatus And Boophilus Decoloratus

Abstract

The objectives of this study were to determine the toxicity of M. volkensii plant extract on the larvae, nymphae and adult Rhipicephalus appendiculatus ticks and to compare the effects with those of the ticks treated with Pyrethrum and Azadirachtin plant extracts. The effects of the plant extracts on the oviposition and hatchability of Boophilus decoloratus female ticks was also determined. The larvae and nymphae were treated with the extracts using the larval packet test whereby unfed larvae and nymphae were placed in filter paper packets which were impregnated with an oil preparation of the plant extracts. The adult ticks were dipped in different concentrations of the plant extracts using the emmersion technique. Significant mortalities (p<0.05) were observed in the treated unfed larvae of R. appendiculatus. The concentration that killed

50% of the treated ticks (LCso) by the extracts was analysed and the results indicates that among the natural products, neem powder performed better (LCso, 1.26g/1) than pyrethrum extract (LCso, 1.95g/1) and M. volkensii (LCso, 2.68g/1) . The results were also compared to Cubex which is an enzyme and SteladoneR which is a standard commercial Organophosphorus acaricide. The oviposition and egg hatchability of B. decoloratus treated with the three extracts was significantly (P<0.05) reduced and at similar concentration the relative potency of the extracts was,

M. volkensii 0.057g>Pyrethrum,O.085g>Neem powder,O.089g>control 0.152g, with M. volkensii reducing the potential reproduction of B. decoloratus by 94% at a high concentration of 100g/l. There was a decrease in the acaricidal activity of the plant extracts against nymphae and adults with the lowest sensitivity being found in the adult ticks. However, when M. volkensii extract was injected at 500~g/tick, into the engorged tick haemolymph, the adult R.appendiculatus ticks were more sensitive and died 4 hrs after the treatment. Natural products from Melia volkensii, Azadirachta Indica and Chrysanthemum Cinerariafolium plant extracts have strong acaricidal activity against Rhipicephalus appendiculatus and Boophilus decoloratus ticks. From this data, it is concluded that all the three plant extracts are suitable for use in an integrated tick control programme but the use of M. volkensii and neem extracts is limited by their low solubility in water and their less penetration across » the tick cuticle.