Muyobela Jackson, Nkunika Philip Obed Yobe, Mwase Enala Tembo
Department of Biological Science, University of Zambia, Box 32379, Lusaka, Zambia.
Department of Veterinary and Tsetse Control Services, Ministry of Agriculture and Livestock, Box 410110, Kasama, Zambia.
Trop Anim Health Prod. 2015 Dec;47(8):1599-605. doi: 10.1007/s11250-015-0906-4. Epub 2015 Aug 27.
This study was designed to obtain data on the farmer's approach to tick control and to determine whether Rhipicephalus appendiculatus Neuman, Amblyomma variegatum (Fabricius), and Rhipicephalus (Boophilus) microplus (Canestrini) were resistant to amitraz and cypermethrin acaricides, in Isoka District, Zambia. Prevailing tick control practices were documented by administering a semi-structured questionnaire to 80 randomly selected smallholder livestock farmers from four agricultural camps (Longwe, Kantenshya, Kapililonga, and Ndeke) in Isoka District. Modified larval packet test (LPT) bioassay experiments were used to determine the resistance status of the common tick species against amitraz and cypermethrin acaricides. Fifty percent of respondents practiced chemical tick control with amitraz (27 %) and cypermethrin (23 %) being the acaricides in use, and were applied with knapsack sprayers. Less than 3 l of spray wash per animal was used which was considerably lower than the recommended delivery rate of 10 l of spray wash per animal. No significant susceptibility change to amitraz at 95 % confidence level was observed in R. appendiculatus and A. variegatum against amitraz. However, a significant change in the susceptibility of R. (Bo.) microplus tested with amitraz was detected at 95 % confidence. The test population had a lower susceptibility (LD50 0.014 %; LD90 0.023 %) than the reference population (LD50 0.013 %; LD90 0.020 %). The results indicated that resistance to amitraz was developing in R. (Bo.) microplus. For cypermethrin, no significant susceptibility change at 95 % confidence was observed in any of the three species and thus resistance to this chemical was not observed.
本研究旨在获取赞比亚伊索卡区农民蜱虫控制方法的数据，并确定牛蜱、变异革蜱和微小牛蜱对双甲脒和氯氰菊酯杀螨剂是否具有抗性。通过向伊索卡区四个农业营地（隆韦、坎滕希亚、卡皮利隆加和恩德凯）随机挑选的80位小农户牲畜饲养者发放半结构化问卷，记录了当地流行的蜱虫控制措施。采用改良幼虫包囊试验（LPT）生物测定实验来确定常见蜱虫种类对双甲脒和氯氰菊酯杀螨剂的抗性状况。50%的受访者采用化学方法控制蜱虫，使用的杀螨剂为双甲脒（27%）和氯氰菊酯（23%），通过背负式喷雾器施用。每头牲畜使用的喷雾洗液少于3升，远低于每头牲畜10升喷雾洗液的推荐施用量。在95%置信水平下，未观察到牛蜱和变异革蜱对双甲脒的敏感性有显著变化。然而，在95%置信水平下，检测到微小牛蜱对双甲脒的敏感性有显著变化。测试群体的敏感性低于参考群体（半数致死剂量（LD50）：测试群体为0.014%，参考群体为0.013%；90%致死剂量（LD90）：测试群体为0.023%，参考群体为0.020%）。结果表明，微小牛蜱对双甲脒的抗性正在形成。对于氯氰菊酯，在这三种蜱虫中均未观察到95%置信水平下的显著敏感性变化，因此未发现对该化学药剂的抗性。
