Mosquitoes


Mosquitoes are humans worst enemy. The are transmitters of diseases like malaria, dengue, filariasis, yellow fever, West Nile virus, Japanese encephalitis, etc

Anopheles

Anopheles mosquitoes are found worldwide, mostly in (sub)tropical regions, and comprise many different subspecies, each with different habitats and behaviours. Anophelines can be recognised by their typical body positioning; making a 45 degree angle with the resting surface. These mosquitoes breed in many different types of (mostly stagnant) water bodies, which makes larval control quite difficult. Anopheles mosquitoes can transmit malaria, a disease caused by the parasite Plasmodium. Malaria causes fevers, anaemia and in severe cases (mostly in children <5 years of age) cerebral trauma and death. Malaria occurs mostly in (sub)tropical regions and causes an estimated 300 million infections and 0.7-1.2 million deaths each year. There is still no commercial malaria vaccine available and the few anti-malarial drugs are losing their efficacy due to drug-resistance. Because Anopheles mosquitoes typically feed at night, mostly indoors, malaria control efforts largely focus on targeting the host-seeking female mosquitoes with indoor-based control products such as insecticide-treated bednets and indoor spraying of residual insecticides. However, the increasing occurrence of insecticide resistance in malaria vectors, as well as changes in their behaviour (outdoor biting and not only at night) are severely reducing the efficacy of these current malaria vector control tools.

Aedes

Aedes mosquitoes are highly invasive and adaptive and can be recognised by the white stripes on their body and legs. Two of the most important species are Aedes aegypti (yellow fever mosquito) and Aedes albopictus (Asian tiger mosquito). They bite during the day, and can thus not be stopped by bednets. Aedes mosquitoes breed in small (mostly man-made) water containers and their eggs can survive long periods of drought, which makes larval control very difficult. Aedes mosquitoes can transmit several diseases such as Dengue, yellow fever and Chikungunya. Dengue is a virus that causes high fevers, joint pains, and in some cases internal bleeding which can be fatal. Dengue is endemic in more than 120 countries worldwide, mostly in Central and South America and Asia. Approximately 100 million people get infected on a yearly basis, of which an estimated 25.000 people die. There is no commercial vaccine against dengue and there is no specific medication. Currently, the only options for dengue vector control are area-wide fogging of insecticides and larviciding. These methods are not exactly human- and environment-friendly and are already faltering due to increasing levels of insecticide resistance.

Culex

Culex mosquitoes are often present in high numbers, are, found all over the globe, and are considered the main nuisance mosquito species. The common mosquito species found in The Netherlands is the Culex pipiens mosquito. Culex mosquitoes can also transmit diseases such as West-Nile virus, filariasis and avian malaria. West-Nile virus, for instance, can cause fever and in severe cases meningitis or encephalitis in humans. Recent outbreaks of West Nile virus encephalitis in humans have occurred in several developed countries, including the United States and southern Europe. Culex mosquito control is largely based on area-wide larviciding (mostly with chemical insecticides), which is threatened by increasing insecticide resistance and environmental concerns of the public.