Efficacy and effect of entomopathogenic fungi (aspergillus oryzae) for control of ticks of major economic importance of cattle in Tanzania

Abstract

Ticks are important ectoparasites that are responsible for severe economic losses. The use of chemical acaricides is the most common method used to control ticks in livestock. This study was conducted to determine the efficacy of Aspergillus oryzae in controlling ticks to enhance livestock productivity. The efficacy of A. oryzae at different concentrations was evaluated against different stages (larva and adult) of the life cycle of hard tick genera (Rhipicephalus, Boophilus and Amblyomma) using immersion test under laboratory conditions. Field trials were conducted in two cattle herds, which were purposively selected, and a spraying method was used to apply A. oryzae at a concentration of 1 x 106 conidial/mL on all tick infested areas. The results demonstrated a concentration-related increase in mortality in all tested tick genera. The mean mortality of larvae and engorged ticks was statistically significant at p˂0.05 and p˂0.001 respectively in all the tested genera. Egg production was found to decrease with increased A. oryzae concentration. Additionally, there was a statistically significant difference in egg production index and oviposition reduction (p=0.009) while there was no significant difference in egg hatching and product effectiveness at p=0.089 and p=0.004 respectively between the tested tick genera. Under field conditions, trials demonstrated a statistically significant tick reduction on all the treated cattle. This study concludes that A. oryzae has a good acaricidal activity against ticks and hence is one of the potential tick control methods for sustainable tick control schemes.