Mosquito population dynamic (diptera: culicidae) in a eutrophised dam

Abstract

This study observed the mosquito population in a rural eutrophised dam. Larvae of L3 and L4 stages and pupae were dipped out during twelve month collections and the reared to the adult stage for identification. The collections were done along nine metres from the edge of the dam divided in three parts (P1, P2 and P3), each part being 3 m long. P1 did not have vegetation (grass) along its edge,which would reach or sink into the water to promote some shade on the marginal water. A total of 217 adults of four species was identified with the following constancies and frequencies: Culex quinquefasciatus (Say, 1823) (83% and 40.6%), Anopheles (Nyssorhynchus) evansae (Brèthes, 1926) and August (47.62) respectively. The presence of C. quinquefasciatus and the high incidence of Daphinia sp. and also the levels of Organic Nitrogen (0.28 mg/L) and of total Phosphorus (0.02 mg/L) are indications of the eutrophication of the dam. There was a difference regarding the total of Anopheles (A. avansae + A. rangeli) and Culex species (C. quinquefasciatus + C. nigripalpis) between P1 and P2 (χ 2 = 0.0097), P1 and P3 (χ 2 = 0.0005), but not between P2 and P3 (χ 2 = 0.2045).The high C. quinquefasciatus constancy and frequency were confirmed to be a good biological indicator for a eutrophised environment and A. evansae showed a good potential for this environment. Vegetation can be an important factor for anopheline population dynamic also in eutrophic breeding sites.Keywords: breeding, mosquitoes, eutrophication, Anopheles, Culex. Dinâmica populacional de mosquitos em açude eutrofizado ResumoEste estudo observou a dinâmica populacional dos mosquitos em açude eutrofizado na área rural de Paraíba do Sul, Estado do Rio de Janeiro. Foram realizadas 12 coletas mensais de mosquitos imaturos pelo método da conchada em 9 m de borda, divididos em três postos (P1, P2 e P3), com 3 m de extensão cada. O posto P1 difere por não ter vegetação (capim, mato) na margem, alcançando ou penetrando e promovendo alguma sombra na água. Larvas L3, L4 e pupas foram isoladas para a obtenção dos adultos e identificação. Foram identificados 217 espécimes adultos de quatro espécies, com as seguintes constâncias e frequências: Culex quinquefasciatus (Say, 1823) (83% e 40,6%), Anopheles (Nyssorhynchus) evansae (Brèthes, 1926) (92% e 26,7%), Anopheles (Nyssorhynchus) rangeli (Gabaldon, Cova Garcia e Lopez, 1940) (83% e 14,3%) e Culex nigripalpus (Theobald, 1901) (33% e 18,4%), com maiores frequências nos trimestres nov./ dez./jan. (85,7%), maio/jun./jul. (75%), ago./set./out. (29,4%), ago./set./out. (23,5%) e, nos meses dezembro (88,4%), setembro (48,94), (38,3) e agosto (47,62), respectivamente. A presença do Culex quinquefasciatus (40%) e a elevada incidência de Daphinia sp., juntamente com os níveis de Nitrogênio orgânico (0,28 mg/L) e de Fósforo total (0,02 mg/L), indicam a eutrofização do açude. Houve diferença comparando os totais de anofelinos (A. avansae + A. rangeli) com os totais de culicini (C. quinquefasciatus + C. nigripalpis) entre P1 e P...

Effects of Organic Amendments on Microbiota Associated with the Culex nigripalpus Mosquito Vector of the Saint Louis Encephalitis and West Nile Viruses

“…This study and others have shown that C. nigripalpus mosquitoes prefer to lay their eggs and develop in highly eutrophic habitats than their C. quinquefasciatus congeners ( 21 , 23 ). Culex quinquefasciatus was considered to be the dominant species colonizer of eutrophic habitats ( 9 , 24 ), but its abundance during the succession in our mesocosms was negligible compared to that of C. nigripalpus .…”

“…Culex nigripalpus Theobald is a major vector of Saint Louis encephalitis virus and is responsible for transmitting other pathogens in the southeastern United States, including West Nile virus ( 19 , 20 ). Culex nigripalpus is among the dominant mosquito species found during early succession stages of newly developed aquatic habitats, including following rainfall and in polluted treatment wetlands ( 21 – 24 ). Significant genetic variations are known to exist among various populations of C. nigripalpus ( 25 ).…”

Mosquitoes (Diptera: Culicidae) from crepuscular period in an Atlantic Forest area in Southern Brazil

“…strodei (Lopes, 1997) in artificial breeding were reported. Moreover, Mansoniini species found in the fragment, has its growing in perennial aquatic environments which have aquatic plants, and develop very well in anthropogenic environments (Wermelinger et al, 2012;D'Avila and Gomes, 2013).…”