IN VITRO ACARICIDAL EFFICACY OF NEEM (AZADIRACHTA INDICA) OIL AGAINST EAR MITES (OTODECTES CYNOTIS)

Abstract

Neem tree (Azadirachta indica) is an herbal plant that has unique properties against insects. This study aimed to assess the in vitro acaricidal efficacy of Neem seed oil against the ear mite (Otodectes cynotis). A preliminary test was conducted to determine the LC₅₀ of Neem seed oil immersed in distilled water in DMSO. Mites were exposed with approximately 2ml of varying concentrations (0.39%, 0.44%, 0.50%, 0.56%, and 0.62%) of Neem seed extract and were observed at 12 and 24 hours post-exposure. Results of the study showed that the highest concentration (0.62%) of Neem seed oil mixture is considered highly effective against O. cynotis with 86% mortality rate at 12 hours exposure. At 24 hours exposure, the mortality was 98% and was comparable to 2% Ivermectin at 100%. The LC₅₀ of the Neem seed oil against O. cynotis were 0.54% and 0.49% at 12 hours and 24 hours, respectively. The acaricidal activity of the Neem seed oil may be an effect of the secondary metabolites as bioactive compounds that were found during qualitative phytochemical analysis (alkaloids, flavonoids and saponins). The present study showed the acaricidal efficacy of the Neem seed oil in O. cynotis. Its application to other external parasites can be explored.