A Dissertation Submitted in Partial Fulfilment of the Requirements of the Degree of Master’s in Life Sciences of the Nelson Mandela African Institution of Science and Technology
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.