Effects of Desiccation on the Hatchability Rate of Laboratory and Wild Strain Aedes Aegypti (L.) And Aedes Albopictus Skuse Eggs

Aedes eggs are desiccation resistant and this feature enables them to survive and adapt to prolonged drought. Information on hatchability of desiccated Aedes eggs is crucial for estimation of survivorship and thence disease transmission. This study was conducted to determine the hatchability rate of wild and laboratory strain of Aedes eggs after drying and storing indoor or outdoor. Ae.aegypti and Ae.albopictuseggs were collected onto filter paper 10 fully engorged femalesoviposited for 24h. The egg papers were air-dried and keptinside mosquito cages located indoor and outdoor for 2, 4, 7, 14, 30 and 60 daysof storage interval. After each interval, an egg paper was divided into equal portions and submerged in a medium broth for hatchingand observed under an imaging system to determine the first appearance of the larvae. Eggs of both species stored outdoor showed the highest hatchability rate compared to the eggs stored indoor. The earliest appearance of larvae was at 15th minute after submergence. Eggs were still able to hatch after 60 days of storage, though the hatchability rate was reduced. This study reconfirms that Aedes eggs are desiccation resistant and drying does not exert any negative effects on the eggs.