Analysis of composition of sugar meals of wild mosquitoes by gas chromatography

Gas chromatography (GC) was successfully used for the first time to determine the components of natural sugar meals in individual mosquitoes and to determine whether carbohydrases are present in the crops of these insects. Crops of wild mosquitoes collected from a 2-ha cypress swamp north of Gainesville, FL, contained fructose, glucose, sucrose, maltose, turanose, melibiose, erlose, melezitose, raffinose, and a few unidentified carbohydrates. Time course studies with male and female Aedes albopictus showed rapid hydrolysis (> 90%) of sucrose occurring within 2 h of ingestion, whereas melezitose remained relatively unchanged even 8 h after ingestion. The crop extraction/GC analysis technique is an improvement over the cold anthrone test traditionally used for sugar analysis. This procedure is a rapid one-step process used to determine natural sugar sources, hydrolysis, occurrence, and preferences for individual wild sugar-feeding Diptera.