What is the primary method by which mosquitoes transmit diseases?

The primary method by which mosquitoes transmit diseases is by biting and sucking blood. When a mosquito bites a host, it pierces the skin and uses its specialized mouthparts, called a proboscis, to access blood vessels. During this process, the mosquito injects saliva that contains anticoagulants, which helps keep the blood flowing while it feeds. If the mosquito is carrying pathogens, such as viruses or parasites, these can be transmitted directly into the bloodstream of the host, leading to diseases such as malaria, dengue fever, Zika virus, and West Nile virus.

The other options are not the primary transmission routes for mosquito-borne diseases. While contaminated food, airborne particles, and stagnant water are related to different aspects of disease transmission and mosquito breeding habits, they do not involve the direct transfer of pathogens through the act of biting and blood feeding, which is the key mechanism for disease transmission in mosquitoes.