MOSQUITOES (DIPTERA: CULICIDAE) OF PRAGUE

Abstract:
In the Czech Republic there are large areas in the Labe and Morava – Dyje Lowlands where mosquitoes are an almost unberable nuisance following occasional summer floods (e.g. in 1997 and 1998), Aedes vexans and Ae. stictius being the main pest species. The capital of the Czech Republic, Prague, lies approx 20 km from the nearest massive Aedes mosquito breeding places so Aedes mosquito annoyance is rarely a serious problem there. The poster shows results of 20 years observation of mosquito incidence based on annual recordings. 22 species of 5 genera have been recorded on the territory of Prague, area of approx 500 km2: Anopheles claviger Meig., An. messeae Fall., An. plumbeus Steph., Mansonia richiardii (Fic.) Aedes cantans (Meig.), Ae. annulipes (Meig.), Ae. excrucians (Walk.), Ae.flavescens (Mull.), Ae.punctor Kirby, Ae. communis (Deg.), Ae.cataphylla Dyar, Ae. dorsalis (Meig.), Ae. leucomelas (Meig.), Ae. pulchritarsis (Rond.), Ae. sticticus (Meig.), Ae.vexans Meig.,Ae. cinereus Meig., Ae. geniculatus (Oliv.), Culiseta annulata (Schrk.), Cu. morsitans (Theob.), Cu. alaskaensis Ludl. and Culex pipiens L.. Most of the natural breeding places of Aedes mosquitoes were recorded in natural conservation areas or in the larger parks where Ae. cantans was dominant species.Aedes species in Prague rarely bite man indoors. Occasional massive occurrence of biting Ae. vexans was observed in suburban gardens only. Anopheles, Culiseta, Mansonia spp. are of no importance in Prague. The true urban mosquito pests in Prague are mosquitoes of two biotypes (subspecies) of Cx. pipiens complex ,namely Cx. p. molestus Forsk. and Cx. p. pipiens L.. Autogenous and anthropophilic Culex pipiens molestus often breeds in polluted water in the warm cellars of blocks of flats partly flooded from defective piping. Many such breeding habitats have been found in almost all parts of Prague over the last two decades. Cx. p. molestus does not hibernate and bites man severely inside infested buildings even during the winter season. Cx. p. molestus breeding places have also been found in rather unusual places such as in accumulated ground water between rails in the Prague underground, in pools with tropical vegetation in botanical and zoological gardens, sewage treatment plants and sewage canals. Blood-fed Cx. p. molestus females easily lay eggs when confined to a cage. In the last few years anautogenous Culex pipiens pipiens, considered in the past as a strictly ornithophilic species in Central European conditions, has been observed to bite people in Prague homes during nights from the end of August till late October. Cx. p. pipiens females often hibernate in cold cellars. Our hypothesis is that only a small percentage of these females enter homes from outside and bite people more or less accidentally while searching for convenient hibernating places. Females of this species that have fed on human blood have not been observed to lay eggs when confined to a cage and survived forced hibernation. In Prague, Cx. pipiens mosquitoes have never been observed to bite people outdoors.