Mosquitoes / Gnats

Aedes spp., Anopheles spp., Culex spp. and Ochlerotatus spp.

1. Identification

• Common name: Mosquitoes / Gnats
• Scientific name: Aedes spp., Anopheles spp., Culex spp. and Ochlerotatus spp.
• Order: Diptera
• Family: Culicidae

2. Pest description

• Small adults (3–7 mm), slender body and long legs.
• Narrow wings and fine scales, typical of the Culicidae.
• Aquatic larvae, mobile, develop in standing or low-current water.
• Aquatic pupae, comma-shaped, very active.
• Haematophagous females, feed on blood for the maturation of the eggs.

3. Main hosts

• Domestic mammals: cattle, horses, pigs, dogs.
• Birds.
• Humans.
• Species with different preferences, but all with a sanitary and welfare impact.

4. Symptoms and damage

• Painful bites and skin irritation.
• Allergic reactions, oedema and inflammation.
• Stress in animals, reduced appetite and productivity.
• Possible transmission of pathogenic agents (depending on the species).
• Animal welfare problems and discomfort for humans.

5. Biological cycle

• Eggs laid on surfaces close to water or directly in the water.
• Larvae develop in standing water, pools, drinking troughs, ditches, containers.
• Aquatic pupation, followed by the emergence of the adults.
• Rapid cycle at high temperatures.
• Multiple annual generations, especially in spring and summer.

6. Monitoring

• Observation of adults in livestock areas, dwellings and humid areas.
• Identification of larvae in collections of standing water.
• Recording of periods of greater activity (late afternoon and night, depending on the species).
• Assessment of complaints of bites in animals and people.
• Environmental monitoring of sites favourable to larval development.

7. Management measures

• Cultural: elimination of standing water, cleaning of drinking troughs, improved drainage, maintenance of ditches and reduction of water accumulation sites.
• Biological: use of Bacillus thuringiensis israelensis (Bti) at water points, when authorised, and promotion of natural predators such as dragonflies and larvivorous fish.
• Integrated protection: regular monitoring, use of authorised repellents, physical protection of animals and people, environmental management and integration of preventive measures to reduce local populations.

Bibliographic references

• EPPO Global Database – Culicidae.
• CABI Invasive Species Compendium – Aedes, Anopheles, Culex and Ochlerotatus spp..
• Becker, N. et al. (2010). Mosquitoes and their control.
• Service, M. W. et al. (2008). Medical entomology for public health.