Galeal Structure in Adult Mosquitoes

Abstract

IN a previous communication¹, studies of the finer structure of the galeæ in adult mosquitoes were reported. It was pointed out that the galea formed the functional maxilla and typically consisted of a strengthening chitinous rod with a fine outer lamella the tip of which carried a number of variously shaped teeth. Further studies, ranging over eight genera of mosquitoes of the Ethiopian region, have revealed that although there is a variety of morphological types, a progressive reduction in the outer lamella is evident. It should be noted that generic and specific differences in the mouth parts of adult mosquitoes have only been poorly investigated², and early studies described only general morphological differences in the trophi, usually of species of known medical and veterinary importance^3–5. In the present studies, freshly killed mosquitoes were used whenever possible and the heads were soaked in 5 per cent potassium hydroxide for 48 hr. After this they were transferred to a slide, the trophi teased apart with a fine steel point and mounted in polyvinyl alcohol. General examination was carried out at × 100 and detailed examination at × 450.