1 research outputs found
Adult immersion test for assessment of amitraz resistance in Rhipicephalus sanguineus ticks
Ticks are obligate blood sucking ectoparasites recognised globally as vectors of various
pathogens, next to mosquitoes. The present study is conducted on brown dog ticks collected
from naturally infested dogs in and around Thrissur district. Adult immersion test was performed
and the parameters such as engorged tick weight, egg mass weight as well as tick mortality were
recorded to derive the reproductive indices, percentage inhibition of oviposition and percentage
mortalities. Non-linear regression analysis of the dose response data yielded the LC50 values at
95% confidence intervals and, the slopes and regression coefficients of the different parameters
were also derived. The Resistance factors (RF) were calculated to categorise resistance levels
into I, II, III and IV. Resistance to amitraz was detected at level II in tick isolates collected from
Choolissery and Mundur, at level III and level IV in isolates collected from Mannuthy and Paravattani,
respectively. Two isolates collected from Mannuthy were found to be susceptible. One way ANOVA
of resistance levels revealed that the resistance levels III and IV were significantly different from that
of susceptible and resistance level II. This is the first report on detection of amitraz resistance levels
in dog ticks from south India calling for proper implementation of tick control strategies to prevent
spread of amitraz resistance