Resistance of cattle tick Rhipicephalus (Boophilus) microplus (Canestrini) to deltamethrin, amitraz and moxidectin in New Caledonia: Review of the situation and perspectives for tick control

Abstract

Cattle tick Rhipicephalus microplus, introduced in New Cal­edonia in 1942, has a significant impact on cattle health and farm profitability. The control of this parasite, based to date on the use of acaricides, led to the development of resist­ance to the chemicals successively available on the market. To assess the status of resistance to the latest products, a sur­vey based on resistance tests to deltamethrin, amitraz and moxidectin was implemented between October 2013 and September 2014. The aims were to establish the efficiency of amitraz which had been in use for 18 years in New Caledo­nia, to assess a possible re-use of deltamethrin 10 years after discontinuing its distribution, and to monitor the emergence of a possible resistance to macrocyclic lactone whose use is currently restricted. According to the selected resistance cri­teria, the resistance prevalence, or an intermediate status, to deltamethrin and amitraz was 25.8 and 23.0 %, respectively. No resistance to moxidectin was found. In the context of the progressive development of resistance to amitraz, tick-con­trol management was transferred to a health defense associa­tion (Groupement de défense sanitaire), which was expected among other missions to develop integrated parasite-control programs. Based on the observed results, this article presents the possible change in tick-control management in New Cal­edonia, which has to evolve from an exclusive and intensive use of chemicals to a set of complementary measures within the framework of an integrated control led by professionals.