Aspectos bioecológicos de Haemagogus leucocelaenus (Diptera: Culicidae) em fragmento florestal urbano do Rio de Janeiro – RJ

Abstract

Knowledge of the biocenotic structure of mosquito communities is of fundamental importance in areas where the environment has been suffering from a rupture of natural equilibria. Such interference may become dangerous, especially when direct contact occurs between these Culicidae and the local human population. In this way, understanding the aspects involved in all phases of the biological cycle of this group becomes of extreme relevance, to better understand its bioecology. Haemagogus leucocelaenus (Dyar, 1925) is a Culicidae considered to be a vector of wild yellow fever and is highly adaptable to modified environments when compared to other species of the same genus. This culicid is commonly found in Brazil and its epidemiological importance is related to arbovirus transmission. The main goal of the present work is contributing to the knowledge about the biological cycle and hatching rate of Haemagogus leucocelaenus eggs, besides investigating the preferential height of oviposition of this species, in an urban area of the Atlantic Forest of Rio de Janeiro. The eggs were collected with an oviposition trap. In total, 4,553 units were collected in all months of the year. The months that obtained the highest number of eggs were October (16.87%) and May (15.13%), and the months with the lowest number of eggs were December (1.36%) and July (1.56%). All the eggs belonged to the same species of mosquito: Haemagogus leucocelaenus. The results also showed that traps installed at different heights, from ground level up to 8 meters high, received similar amounts of eggs. This shows that this species explores different levels of the arboreal extract, which can favor the transmission of pathogens between arboreal animals and man. To evaluate the hatching rate of eggs during successive immersions under laboratory conditions, 875 units were collected, collected in October and November, of which 323 (36.9%) hatched. The first dipping to which the eggs were submitted presented the highest hatchability, for both months, decreasing abruptly after the 5th and 7th immersion. The study provides relevant information on the bioecological aspects of the species and emphasizes its epidemiological importance.