Up to the present, we have found 70 kinds of mosquitoes in Hong Kong. The most common kinds are Aedes Albopictus, Anopheles Minimus, Anopheles Jeyporiensis, Culex Pipiens Quinquefasciatus, Aedes Togoi and Culex Tritaeniorhynchus.
The life cycles of mosquitoes vary widely from species to species. Some female mosquitoes lay single eggs on water surfaces; others lay single eggs on moist soil where later flooding is likely. Still other species lay batches of eggs, called rafts, 100 or more at a time on water surfaces. Eggs deposited on water surfaces usually hatch within a day or so, but eggs laid on soil surfaces do not hatch until flooding occurs, which may be months or even years later.
Larvae, which are nearly invisible to the naked eye, hatch from eggs. Larvae molt three times to become 4th-stage larvae. Several days later, this larval form molts again to become a pupa. Adult mosquitoes emerge from pupae 1 to 2 days after that, with male mosquitoes always emerging first. In summer the entire life cycle, from egg to adult, may be completed in a week or less.
Female mosquitoes of nearly all species require blood from vertebrate animals to develop eggs, and many species bite people, pets, and livestock for this purpose. The most important consequence of this is the transmission of microorganisms that cause diseases.
Zika virus infection is a mosquito-borne disease caused by Zika virus. The infection may associate with adverse pregnancy (microcephaly) and neurological and autoimmune complications such as Guillain-Barré syndrome (GBS). The World Health Organization has concluded that Zika virus infection during pregnancy is a cause of congenital brain abnormalities, including microcephaly, and that Zika virus is a trigger of GBS.
Zika virus can be transmitted to humans through the bites of infected Aedes mosquitoes. In Hong Kong, the local species such as Aedes albopictus can be considered as potential vectors.
Dengue fever is an acute mosquito-borne infection caused by the dengue viruses. This is found in tropical and sub-tropical regions around the world. For instance, dengue fever is an endemic illness in many countries in South East Asia. The principal type of mosquito that transmits the disease is called Aedes. The dengue viruses encompass four different serotypes, each of which can lead to dengue fever and dengue haemorrhagic fever.
What is Japanese encephalitis Japanese encephalitis is a mosquito-borne disease caused by the Japanese encephalitis virus. The virus is transmitted by the bite of infected mosquitoes . The principal type of mosquito that transmits the disease is called Culex Tritaeniorhynchus. The disease occurs mainly in the rural and agricultural areas of Asia and the Western Pacific Region. It is a rare disease in Hong Kong. There are less than 10 cases reported in the past ten years.
Malaria is a serious and sometimes fatal disease caused by a group of malaria parasites, namely Plasmodium vivax, Plasmodium falciparum, Plasmodium ovale, and Plasmodium malariae. The principal type of mosquito that transmits the disease is called Anopheles. It is commonly found in many parts of tropical and sub-tropical areas where the climate is warm, like Africa, South-East Asia and South America.