Nazari Mansour, Motlagh Behrouz Alipourian, Nasirian Hassan
Department of Medical Entomology, School of Medicine, Hamadan University of Medical Sciences, Hamadan, Islamic Republic of Iran.
Department of Medical Entomology and Vector Control, School of Public Health, Tehran University of Medical Sciences, Tehran,Islamic Republic of Iran.
Pak J Biol Sci. 2016;19(6):259-264. doi: 10.3923/pjbs.2016.259.264.
German cockroach has relatively short life cycle and reproduce rapidly. It is the most common medically and public health pest. As a result, it is essential to combat this pest. Cypermethrin and chlorpyrifos are used by private companies in Hamadan to control Blattella germanica. It seems necessary to determine its susceptibility levels to these insecticides.
The aim of this study was to determine the susceptibility levels of B. germanica strains to cypermethrin and chlorpyrifos in Hamadan.
In this study, the German cockroach strains were collected from two hospitals (Fatemiyeh and Atiyeh) in Hamadan and transfered to the insectarium. The cockroach strains were reared under the same laboratory condition. Then their sensitivity levels were considered to 1, 2, 4, 8 and 16 mg m -2 for cypermethrin and 0.82, 1.65, 3.31, 6.63, 9.945 and 13.26 mg m -2 for chlorpyrifos using surface contact method.
Results based on insecticide treated doses, B. germanica strains showed different percent mortality to the insecticides ranged from 13.3-100. The LD 50 and LD 90 and regression lines of the treated insecticides against German cockroach strains indicate that Fatemiyeh Hospital strain is more susceptible to the treated insecticides than Atiyeh Hospital strain. The LD 50 and LD 90 of chlorpyrifos are also lower than cypermethrin, indicated that chlorpyrifos is more effective than cypermethrin against German cockroach. As the slopes of the regression lines are observed mild in this study indicate that the population of the cockroach strains is very heterogeneous. It can be a symbol of insecticides resistance to cypermethrin and chlorpyrifos.
As chlorpyrifos and cypermethrin insecticides are also used for residual spraying by private companies and the doses which provide more than 90% mortality are below the WHO recommended insecticide doses. Therefore, chlorpyrifos and cypermethrin insecticides can be used for B. germanica control in Hamadan within regular monitoring and preventive measures of resistance.
德国小蠊生命周期相对较短且繁殖迅速。它是医学和公共卫生领域最常见的害虫。因此，防治这种害虫至关重要。哈马丹的私人公司使用氯氰菊酯和毒死蜱来控制德国小蠊。确定其对这些杀虫剂的敏感性水平似乎很有必要。
本研究的目的是确定哈马丹德国小蠊品系对氯氰菊酯和毒死蜱的敏感性水平。
在本研究中，从哈马丹的两家医院（法特米耶医院和阿提耶医院）收集德国小蠊品系并转移至昆虫饲养室。蟑螂品系在相同实验室条件下饲养。然后，使用表面接触法，对于氯氰菊酯，将其对药剂的敏感性水平设定为1、2、4、8和16毫克/平方米，对于毒死蜱，设定为0.82、1.65、3.31、6.63、9.945和13.26毫克/平方米。
基于杀虫剂处理剂量的结果，德国小蠊品系对杀虫剂的死亡率百分比不同，范围为13.3% - 100%。处理后的杀虫剂对德国小蠊品系的半数致死剂量（LD50）、致死率达90%时的剂量（LD90）以及回归线表明，法特米耶医院品系比阿提耶医院品系对处理后的杀虫剂更敏感。毒死蜱的LD50和LD90也低于氯氰菊酯，表明毒死蜱对德国小蠊比氯氰菊酯更有效。由于本研究中观察到回归线的斜率较平缓，表明蟑螂品系的种群非常异质。这可能是对氯氰菊酯和毒死蜱产生抗药性的一个标志。
由于毒死蜱和氯氰菊酯杀虫剂也被私人公司用于残留喷洒，且提供超过90%死亡率的剂量低于世界卫生组织推荐的杀虫剂剂量。因此，在进行定期监测和抗药性预防措施的情况下，毒死蜱和氯氰菊酯杀虫剂可用于哈马丹德国小蠊的防治。
