In vitro Study on Comparative Efficacy of Commercially Available Acaricides and Crude Extracts of Solanum incanum and Nerium Oleander against Ticks

This study was carried out from November 2017 to June 2018 to compare the efficacy of commercially available acaricides of Diazinon 60% and Steladone 300EC and Ethanol extracts of Solanum incanum and Nerium oleander for their acaricidal activity against Rhipicephalus pulchellus and Amblyomma variegatum engorged female ticks collected from naturally infested cattle using in vitro adult immersion method. Leaf of Nerium (N.) oleandera and fruits of Solanum (S.) incanum was collected from natural habitat of Mekelle city and extracted with maceration technique by 80% ethanol. Steladone 300EC exhibited highest efficacy (p<0.05) against both ticks than Diazinon 60%. However, there was no statistically significant difference (p>0.05) between both acaricides regarding oviposition inhibition effect in both tick species. The highest inhibition of oviposition (92%) and (85%) was revealed by Steladone 300EC against A. variegatum and Rh. Pulchellus, respectively. On the other hand, crude extract of N. oleandera has lowest acaricidal effect than S. incanum. Crude extract of N. oleandera inhibited oviposition within range of 18.7 to 29.6% while S. incanum inhibited 66.3 to 76.4%. Promising results were obtained by S. incanum on A. variegatum at low concentrations. Crude extracts of S. incanum fruits have acaricidal effects (67%) comparable to Diazinon (76%). Therefore, crude extract of S. incanum can be a potential acaricide to replace Diazinon.