Dzemo William Diymba, Vudriko Patrick, Ramatla Tsepo, Thekisoe Oriel
Department of Biological and Environmental Sciences, Faculty of Natural Sciences, Walter Sisulu University, Mthatha 5117, South Africa.
Unit for Environmental Sciences and Management, North-West University, Potchefstroom 2531, South Africa.
Pathogens. 2023 Jun 26;12(7):875. doi: 10.3390/pathogens12070875.
Chemical acaricides are widely used to control ticks and tick-borne pathogens in cattle. However, prolonged and indiscriminate use of these chemicals inevitably leads to the selection of resistant ticks. In-vitro bioassays (adult and larval immersion tests) were conducted to assess amitraz and deltamethrin resistance in populations from communal farms of the King Sabata Dalindyebo municipality of South Africa. Data generated on percentage inhibition of oviposition (%IO) revealed that all the tick populations assessed showed resistance (%IO ≤ 95%) to at least one of the acaricides. All six tick populations assessed for efficacy (%IO ≥ 95%) at the DD) with deltamethrin were resistant (%IO ≤ 95%) and only one of the six tick populations assessed for efficacy with amitraz was susceptible. Based on the resistance ratios (RR), the adult immersion test detected amitraz and deltamethrin resistance in three (RR ranging from 2.30 to 3.21) and five (RR ranging from 4.10 to 14.59) of the six tick populations, respectively. With the larval immersion test, deltamethrin and amitraz resistance (larval mortality < 90% at the DD) was detected in all four and three of four populations assessed, respectively. These data are critical for the design of an effective and sustainable tick control strategy on the communal farms.
化学杀螨剂被广泛用于控制牛身上的蜱虫及蜱传病原体。然而，长期且无差别地使用这些化学药剂不可避免地导致了抗药性蜱虫的出现。开展了体外生物测定（成虫和幼虫浸泡试验），以评估南非萨巴塔·达林迪耶博国王市社区农场的蜱虫种群对双甲脒和溴氰菊酯的抗药性。关于产卵抑制率（%IO）的数据显示，所有评估的蜱虫种群对至少一种杀螨剂表现出抗药性（%IO≤95%）。用溴氰菊酯在规定剂量（DD）下评估药效（%IO≥95%）的所有六个蜱虫种群均具有抗药性（%IO≤95%），而用双甲脒评估药效的六个蜱虫种群中只有一个易感。根据抗药率（RR），成虫浸泡试验分别在六个蜱虫种群中的三个（RR范围为2.30至3.21）和五个（RR范围为4.10至14.59）中检测到对双甲脒和溴氰菊酯的抗药性。在幼虫浸泡试验中，在评估的四个种群中的所有四个以及四个种群中的三个中分别检测到对溴氰菊酯和双甲脒的抗药性（在规定剂量下幼虫死亡率<90%）。这些数据对于在社区农场设计有效且可持续的蜱虫控制策略至关重要。
