SEM of a mosquito leg (Anopheles stephensi) clearly showing individual scales. Anopheles stephensi is one of the major vectors of urban malaria in India and some parts of Asia. Malaria is caused by parasites (Plasmodium species) which enter the blood when infected mosquitoes feed. Anopheles stephensi is commonly used in research as it can be easily reared and maintained in the laboratory. False-coloured scanning electron micrograph; x 400; width of one scale is approximately 12 micrometers.