[Spatial distribution of Aedes albopictus in the southern area of Mato Grosso do Sul State, Brazil].
OBJECTIVE
To investigate the spatial distribution of Aedes albopictus population to provide input for developing sampling plans and supporting decision making on the control of this vector in field sampling.


METHODS
A study was carried out in an urban area that has a vestige of primary vegetation, 20 km away from Dourados, Midwestern Brazil. Ten samplings were conducted between January 28, 2003 and April 9, 2003, using ovitraps which were monitored once a week, and distributed in a fixed sample area with 10 collection points for each sampling 300 m away from each other. Aggregation indexes were calculated and adjusted to the following theoretical frequency distribution: negative binomial, positive binomial and Poisson's.


RESULTS
The sample variance was higher than the sampling mean, resulting in mean-variance indexes above the unit (32.066, 29.410, 14.444, 58.840, 56.042, 111.262, 70.140, 50.701, 93.221 and 8.481). Morisita's index was also statistically above the unit in all samplings (6.275, 3.947, 1.484, 3.725, 3.014, 5.450, 3.214, 3.886, 3.954 and 5.810), and K parameter ranged 0 and 8 (0.174, 0.309, 1.867, 0.332, 0.449, 0.203, 0.408, 0.314, 0.306 and 0.200). The Chi-square test for adjustment to the negative binomial distribution, positive binomial distribution, and Poisson's distribution was not statistically significant.


CONCLUSIONS
Ae. albopictus population in the studied municipality showed an aggregated standard spatial distribution. This means that when individual vectors are found in a certain site, it is likely that other vectors can be found in the proximities, recommending insecticide spraying for vector control in this site without requiring sampling other sites in this same locality.
de Almeida
Paulo Silva
PS
Laboratório Regional de Entomologia, Núcleo Regional de Saúde, Secretaria de Estado de Saúde do Mato Grosso do Sul, Dourados, MS, Brasil. psilvadealmeida@yahoo.com.br
Ferreira
Ademar Dimas
AD
Pereira
Veruska Lopes
VL
Fernandes
Marcos Gino
MG
Fernandes
Wedson Desidério
WD
D000330:Aedes / Q000502:physiology*; D000818:Animals; D001938:Brazil; D003715:Dengue / Q000635:transmission; D007303:Insect Vectors / Q000502:physiology*; D007814:Larva / Q000502:physiology; D009032:Mosquito Control; D010058:Oviposition / Q000502:physiology; D011156:Population Density; D012494:Sampling Studies; D016008:Statistical Distributions