ABSTRACT
The objective of this study was to assess the parity, presence of blood in the stomach, and the gonotrophic discordance of females of Aedes aegypti and Aedes albopictus captured in two areas of the city of São Paulo. The captures were undertaken monthly, by aspiration, in the period from January, 2015 to August, 2017. All the females of the two species had their midguts and ovaries dissected to determine the presence of blood and the parity/stage of maturation. With regard to parity, 27% and 34% of the females of Ae. aegypti and Ae. albopictus, respectively, were parous or were in advanced stages of the development of their ovaries (33% and 27%, respectively). The larger part of the females of Ae. aegypti and Ae. albopictus contained blood in their stomachs (77% and 60%, respectively), beyond which 36% and 27% of the females of Ae. aegypti and Ae. albopictus, respectively, were in gonotrophic discordance. Our results indicate favorable conditions in the study areas because of the presence of parous females. Moreover, this frequent and multiple contact of Ae. aegypti and Ae. albopictus females with vertebrate hosts, such as humans, increases the possibility of transmitting the viruses they may be carrying.
Subject(s)
Aedes , Mosquito Vectors , Animals , Female , Aedes/physiology , Aedes/virology , Brazil , Cities , Mosquito Vectors/physiology , Mosquito Vectors/virologyABSTRACT
Vector blood-feeding frequency, parity, and ovarian development are important factors that can influence pathogen transmission. Parity rates of the dengue vectors Aedes aegypti and Ae. albopictus were determined from females collected from August 2002 to July 2004 in metropolitan Rio de Janeiro. A high frequency of parous Ae. aegypti (92.9%, n = 550) and Ae. albopictus (99.1%, n = 320) females suggested high survivorship of both species. A total of 69% of wild-caught Ae. aegypti females had blood in the midgut compared to 19% of Ae. albopictus. For Ae. aegypti, red-colored midgut contents were associated with ovaries in early stages of development, and brown-colored midguts were associated with ovaries in late stages of maturation. Ovaries of Ae. aegypti females without blood in the midgut were most frequently in stages I and V of Christophers.
Subject(s)
Aedes/growth & development , Culicidae/growth & development , Ovary/growth & development , Aedes/physiology , Animals , Brazil , Culicidae/physiology , Female , Insect Vectors/growth & development , Insect Vectors/physiology , Ovary/physiology , Population DensityABSTRACT
We evaluated the intra- and peri-domiciliary distribution of Aedes aegypti and Ae. albopictus in urban, suburban, and rural districts in the municipalities of Nova Iguaçu and Rio de Janeiro, Brazil, from August 2002 to July 2004. Mostly Ae. aegypti females and males were captured in urban areas (56%) and indoors (78%), suggesting a preference by this species to rest inside houses and in areas with high human density, a behavior that favors vector-human contact. Meanwhile, Ae. albopictus females and males were much more common in rural areas (93%) and outdoors (90%), demonstrating their preference to rest in areas with more vegetation, reducing both the probability of vector-human contact and thus their potential role in dengue transmission in the area.
