Morphological sexual dimorphism in three species of anopheline mosquito larvae

Sexual separation at the larval stage in anopheline mosquitoes with the naked eye is difficult. We have identified distinguishing spots visible to the naked eye on the 6th abdominal segment of 3rd and 4th instars of Anopheles stephensi, An. culicifacies, and An. subpictus. Based on this feature, male and female larvae can be differentiated morphologically at 3rd and 4th instars of these species. This is the first report on these characteristic spots that may have a wide application for larval sexing in mosquito taxonomy, physiology, toxicology, genetics, and control.