Dispersion of Aedes aegypti (Linnaeus, 1762) and Aedes albopictus (Skuse, 1894) in the rural zone of north Paraná State

Abstract

Seventy-two tyres were placed in four transects (Northern, Southern, Eastern and Western), every 5 km, from the Londrina city limits to the rural areas, to verify the dispersion of Aedes aegypti and Ae. albopictus vectors. Mosquito larvae were collected fortnightly from August 1998 to August 1999. Data were organized according to the average number of larvae collected for each species in each collection site. A total of 62,517 mosquito larvae were collected and distributed into the following species: Aedes albopictus (21.71%); Ae. aegypti (5.54%); Ae. terrens (0.53%); Ae. fluviatilis (0.36%); Anopheles argyritarsi (0.01%); Culex quinquefasciatus (48.37%); Cx. mollis (8.88%); Cx. eduardoi (8.65%); Cx. corniger (0.61%); Cx. bigoti (0.24%); Cx. grupo coronator (0.12%); Limatus durhanii (4.61%) e Toxorhynchites sp. (0.32%). There was a drastic decrease in the Ae. aegypti population from the city limits to the rural area (x1= 21.72 ± 4.71; x2=0.00) and an increase in the population of Ae. albopictus (x1 = 15.64 ± 2.73; x2 = 38.37 ± 8.87). Aedes aegypti was not present in the collection sites located 30 km away from the urban area; however, Ae. albopictus was found in all the sites. Although the frequency rate for the Aedes aegypti was low, both species were dispersed in the rural area studied. The redimensioning of these vectors’ control areas is recommended since rural areas can function as reservoirs for these species.