Insecticide Resistance in Mosquito Populations

Insecticide is an important tool for controlling mosquito-borne diseases, such as malaria. There are different methods of insecticide application, including thermal foggers and ultra-low-volume foggers. Indoor residual spraying (IRS) with long-lasting insecticide is also commonly used in Africa to prevent malaria transmission. In addition, insecticide-treated bed nets, such as ITN and LLIN, are an effective way to reduce malaria transmission at night.

There are four groups of insecticides commonly used to kill mosquitoes: organochlorine, organophosphate, carbamate, and pyrethroids. However, mosquito populations can develop resistance to these insecticides. Resistance can occur through multiple resistance and cross-resistance. Multiple resistance is when mosquitoes are resistant to two or more insecticides with different mechanisms of action, while cross-resistance is when mosquitoes are resistant to more than one insecticide with the same mechanism of action.

To minimize the occurrence of insecticide resistance, it is important to follow standard operating procedures when spraying insecticides. In addition, careful evaluation and understanding of the mechanisms of resistance are required when designing appropriate strategies to reduce the population of resistant mosquitoes.

Review questions:

• What are the different methods of insecticide application?
• What is indoor residual spraying (IRS)?
• How do insecticide-treated bed nets work?
• What are the four groups of insecticides commonly used to kill mosquitoes?
• How can the occurrence of insecticide resistance be minimized?