Tick imperviousness to acaricides is an expanding issue in Pakistan and represents a genuine financial danger to the domesticated animals and veterinary pharmaceutical enterprises. New acaricides are to a great degree costly to grow so the present acaricides ought to be viewed as a constantly decreasing asset, which ought to be ensured by all methods conceivable. The principle goal of the review was to distinguish the stages of tick imperviousness to acaricides at close business and collective ranges in District Narowal, Pakistan. Likewise to contrast the in vivo techniques and with explore acaricide administration procedures which may build the life expectancy by utilized acaricides.
To meet these points a field survey (February 2016 to March 2017) was carried out at 3 tehsils (Tehsil Narowal, Shakargharand Zafarwal cities of Pakistan to monitor levels of field tick resistance to acaricides. The larvae were originally obtained from engorged female A.hebraeum, Hyalloma, Boophilus, Dermacentor, Ixodes, R. appendiculatusand R. evertsievertsi. The larvaewere tested against different concentrations of trichlorofon, ivermectin and cypermethrin using the Shaw Larval Immersion Test (SLIT). Mortality dose data were subjected to probit analysis using a BMDP statistical package. Factors of resistance (FOR) were calculated by comparing the larval response of ticks from the field.
On the communal farms high levels of tick resistance were detected to cypermethrin as well as partial resistance to ivermectin whilst no resistance was detected against trichlorofon. On the commercial farms, however, ticks were equally resistant to trichlorofon, cypermethrin and ivermectin. The populations of Hyalloma, Boophilus, Dermacentor, Ixodes, on these farms had developed higher levels of resistance to the testacaricides than the equivalent R. evertsievertsi, R. appendiculatus and A.hebraeumpopulations. Higher levels of tick resistance to trichlorofonwas observed on3 tehsils (Tehsil Narowal, Shakarghar and Zafarwal)than on communal farms, however, there was no significant differences in tick resistance to ivermectin and cypermethrin at both the commercial and communal farms. It was surmised that inappropriate use of acaricides might have resulted in higher tick resistance to the currently available acaricides on the commercial as well as the communal farms. Correct acaricide usage may solve this problem to a limited extent.
Comparative in vivo tests were also carried out on the larvae and adults of Hyalloma, Boophilus, Dermacentor, Ixodes, to determine the susceptibility of this tick to different concentrationsof the currently used acaricides, (amitraz, ivermectin and cypermethrin) at three commercial dairy farms, (“Brycedale”, “Sunny Grove” and “Welgevind”) in the areas of District Narowal, Pakistan. Resistance of field strains of Hyalloma, Boophilus, Dermacentor, Ixodes, Dermacentor,were determined using the Adult Immersion Test (AIT) as the latter test took into account factors such as oviposition assessment and reproductive ability. At “Brycedale”, resistance to trichlorofon and ivermectin was detected with the AIT method. Emerging resistance to trichlorofon and resistance to ivermectin were also detected . At “Sunny Grove” resistance was detected to cypermethrin and at “Welgevind” resistance was detected to ivermectin with the SLIT whilst no resistance was detected using AIT. It would appear that the Hyalloma, Boophilus, Dermacentor, Ixodes, populations tested on these dairy farms were more resistant toivermectin than to trichlorofon or cypermethrin.
Nearly 50% of the dairy farms sampled showed resistance to ivermectin and the majority had susceptible Hyalloma, Boophilus, Dermacentor, Ixodes, populations to both amitraz and cypermethrin. In general there was a good correlation between the Cypermethrin and Trichlorofon whilst in many cases there was poor correlation between the Cypermethrin and Ivermectin.
From this study it would appear that the In vivo method was a reliable to detect resistance within seven days. In vitro method the ELT and the RET could possibly be used as screening methods to detect acaricide resistance on farms whilst the SLIT would remain the test of choice for National surveys. In addition the ELT is less costly and does not require sophisticated equipment for field testing if resistance development compared with other in vitro test methods. This method, however, still needs to be validated and standardized for use in Narowaland the rest of punjab where tick control is important.