The dispersal and survival of the phlebotomines
Nyssomyia intermedia
and
Nyssomyia neivai
(both implicated
as vectors of the cutaneous leishmaniasis agent) in an endemic area was investigated using a capture-mark-release
technique in five experiments from August-December 2003 in municipality of Iporanga, state of São Paulo, Brazil.
A total of 1,749 males and 1,262 females of
Ny. intermedia and 915 males and 411 females of
Ny. neivai were marked
and released during the five experiments. Recapture attempts were made using automatic light traps, aspiration
in natural resting places and domestic animal shelters and Shannon traps. A total of 153 specimens (3.48%) were
recaptured: 2.59% (78/3,011) for
Ny. intermedia and 5.35% (71/1,326) for
Ny. neivai. Both species were recaptured
up to 144 h post-release, with the larger part of them recaptured within 48 h. The median dispersion distances for
Ny. intermedia and
Ny. neivai, respectively, were 109 m and 100 m. The greatest dispersal range of
Ny. intermedia
was 180 m, while for
Ny. neivai one female was recaptured in a pasture at 250 m and another in a pigsty at 520 m,
showing a tendency to disperse to more open areas. The daily survival rates calculated based on regressions of the
numbers of marked insects recaptured on the six successive days after release were 0.746 for males and 0.575 for
females of
Ny. intermedia and 0.649 for both sexes of
Ny. neivai. The size of the populations in the five months ranged
from 8,332-725,085 for
Ny. intermedia males, 2,193-104,490 for
Ny. intermedia females, 1,687-350,122 for
Ny. neivai
males and 254-49,705 for
Ny. neivai females.
