Plasmodium is the causative agent of malaria. All species of mosquitoes of the genus Anopheles alone carry Plasmodium. Anopheles mosquito is the sole carrier of Plasmodium in terms of lifespan, environmental conditions, temperature and duration of bite. Anopheles mosquitoes are good for gamete formation, fertilization, zygotes, oocysts and sporogony of Plasmodium. A crop of Anopheles mosquito is a favorable environment for the growth of bacteria.
Other species of mosquitoes contain toxic substances in their bodies. These toxins are harmful to Plasmodium. The intestines of all those mosquitoes contain trypsin-like substances. These substances inhibit the growth of Plasmodium ookinetes. As a result sporozoites are not formed. But the Anopheles mosquito has no harmful components for Plasmodium. The crop of Anopheles mosquito is a perfect environment for the germs to reproduce. Therefore, only female Anopheles mosquitoes carry malaria.