Aedes aegypti Ecology

Aedes aegypti is the principal mosquito vector of dengue and is closely adapted to human dwellings. Its container-breeding ecology, daytime feeding and tendency to rest near people make household and neighbourhood action central to dengue control.

Domestic breeding pattern

• The mosquito lays eggs in water-holding containers inside or around homes, including tanks, drums, coolers, flower pots and discarded tyres.
• Eggs are commonly attached to container walls near the water line and can withstand dry conditions, allowing them to hatch when the container is refilled.
• Its larvae and pupae are aquatic, so recurrent water storage, irregular supply and poorly managed solid waste create breeding opportunities.
• Adults bite mainly during the day and often rest indoors in sheltered places, increasing human-vector contact.

Control measures derived from its ecology

Because breeding sites are numerous, small and dispersed across private premises, source reduction is the primary control approach and requires sustained community participation.

• Water-storage vessels should be tightly covered, while removable containers should be emptied, scrubbed and dried at least once a week.
• Discarded containers and tyres should be removed or managed so that they cannot collect rainwater.
• Approved larvicides or biological control may be used in water bodies that cannot be emptied or covered, following public-health guidance.
• Screens, protective clothing and repellents are especially relevant during daytime; adult mosquito control during outbreaks supplements rather than replaces source reduction.

Entomological surveillance

Household container surveys reveal where control is failing and permit targeted action.

• The House Index is the percentage of houses infested with Aedes larvae or pupae.
• The Container Index is the percentage of water-holding containers infested with larvae or pupae.
• The Breteau Index is the number of positive containers per 100 houses inspected.

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