life sciences
It is the small ones

Smaller mosquitoes are better at transmitting diseases than larger ones. Researchers in the US fed mosquitoes blood contaminated with dengue virus and tested them for infection. Smaller-sized mosquitoes showed higher infection rates and greater potential to transmit the virus. Even a slight difference in the body sizes of Asian tiger and yellow fever mosquitoes, the main transmitters of the dengue virus, drastically altered their potential to transmit the virus. The researchers, from Illinois Natural History Survey, Oklahoma State University and University of Florida, cautioned that other components like longevity, host preference and feeding frequency also determine a mosquito