Efficacy of Strychnos spinosa (Lam.) and Solanum incanum L. aqueous fruit extracts against cattle ticks

Abstract

The efficacy of Solanum incanum and Strychnos spinosa aqueous fruit extracts was evaluated against cattle ticks in on-station experiments and laboratory tick bioassays. In the on-station experiment using cattle, fruit extracts were applied at three concentrations 5, 10, and 20 % (w/v) and compared with a commercial acaricide, Tickbuster (amitraz) spray (positive control) and no treatment (negative control). The treatments were applied at weekly intervals for 6 weeks as surface sprays on 32 Mashona cattle in a completely randomized design experiment. Ticks on individual cattle were identified, counted, and recorded daily. Peripheral blood samples were collected for parasite screening. In the laboratory, tick bioassays were conducted at four concentrations, 5, 10, 20, and 40% (w/v) fruit extracts compared to Tickbuster (amitraz) spray (positive control) and distilled water (negative control). The extracts were incubated with Rhipicephalus (Boophilus) decoloratus tick larvae and mortalities for each treatment level recorded after 24 and 48 h. The 5% Solanum incanum treatment had higher efficacy ratio (P < 0.05) than the other fruit extract concentrations of the same plant species. Efficacy ratio was higher (P < 0.05) in the 5% S. spinosa-treated cattle than in the untreated control but lower (P < 0.05) than that for the amitraz treatment. The bioassays indicated that there was a high efficacy ratio for the lowest fruit extract concentrations when ticks were exposed to acaricidal treatments for 48 h compared to 24 h. Overall, the results indicate that Solanum incanum and Strychnos spinosa individually have some acaricidal effect.

Local processing and nutritional composition of indigenous fruits: The case of monkey orange (Strychnos spp.) from Southern Africa

“…(47) Toxic effects of kingiside aglucone in mice were reported for high dosage of unripe pulp of S. spinosa; however, specific searches with extracted ion chromatograms for strychnine, brucine and associated compounds found no terpene indole alkaloids in unripe S. spinosa pulp. (48) The fruit extracts of unripe S. spinosa pulp were also found to be acaricidal on cattle ticks, though the extracts did not show the classical dose dependence that occurs with conventional insecticides (49) and no toxic effects were elicited in guinea pig and mice. (50) For these studies, an extrapolation to human toxicity was not done.…”

A review of the traditional use of southern African medicinal plants for the treatment of selected parasite infections affecting humans

“…Furthermore, Tagetes minuta essential oils also delayed the moulting of engorged nymphs by 60% after 25 days (Nchu et al, 2012). Aqueous Solanum incanum and Strychnos spinosa extracts (5%) were reported to be highly lethal to ticks following a 48 hour treatment (Madzimure et al, 2013).…”

In vitro acaricidal activity of Bobgunnia madagascariensis Desv. against Amblyomma variegatum (Fabricius) (Acari: Ixodidae)

“…However, the majority of resource poor smallholder cattle farmers consider the application of chemical acaricides to cattle to be too expensive (Madzimure et al 2013), which frequently leads to the misuse of products. Inadequate spray volume application, excessive betweentreatment intervals and replacement of acaricides with agricultural pesticides are some of the most common examples of acaricide misuse (Bianchi et al 2003 andMuyobela et al 2015).…”

“…The opportunity to use local, readily available acaricidal plants would be desirable among resource poor smallholder farmers, as they provide a cheaper and safer alternative to synthetic chemical acaricides (Madzimure et al 2013). As such, several plants have been demonstrated to have significant acaricidal properties (Habeeb 2010;Opiro et al 2010;Madzimure et al 2011Madzimure et al , 2013. It appears that the acaricidal properties of Bobgunnia madagascariensis (Desv.)…”