Research on the mosquitoes of Angola - Systematic Catalog of ...

RIBEIRO, H. & RAMOS, H. Cunha -- <strong>Research</strong> on the mosquitoes of Atgola -- X
DISTRIBUTION. Map 10 shows the known distribution of C. duttoni
in Angola, one of the most generalized and common mosquitoes in the
country as well as in all the Tropical Africa.
BIOEGOLOGICAL NOTES. Only 17 out of our 342 adult specimens
of C. duttoni were in fact caught as adults, 10 of which (4 9, 6 )
were taken inside human habitation: one fernmale while biting man
and the other specimens resting on walls. The remaining adults (5 9,
2 3) were caught in the outside, resting near their breeding places:
on the inner walls of barrels, on vegetation and in crabholes. C. duttoni
seems to be, thus, a mainly zoophilic mosquito, though it easily
enters houses and occasionally bites man.
One hundred of breeding places were recorded by the writers for
duttoni in Angola. 29 out of these consisted of naturally occurring
water collections: ground water in 19 instances, rock-pools in 8, a
banana axil and a hole in a fallen baobab. 21 out of the 71 man-made
la:val biotopes of duttoni consisted of two main kinds of ground water;
borrow-pits and shallow earth wells and holes, often with decaying
, or other vegetables (16) and small ditches and
earth drains (5). The remainder 50 man-made breeding places were
represented by artificial containers in peridomestic habitat: 30 storage
containers with water for domestic uses (barrels and drums), 16 discarded
objects (11 rubber tyres and 5 vases, tins, etc.) and 4 cement
water tanks.
The breeding water was sometimes clean and limpid, but more
often it was turbid and foul from decaying plants. The pH was measured
in 25 breeding places, showing figures from 5.1 to 8.0. Most
biotopes (21), however, had an acid water (5.1-6.7), while only in 2
of them the water was neutral, and figures over 7.0 were only found
in other 2 instances (7.2 and 8.0). The salt content of the breeding
water from a crabhole at Moqttmedes (coast) was measured, giving a
figure of 1.29 g/1 (NaCl).
Many species were found as associates in the breeding biotopes
of C. duttoni, the most common of which were, by decreasing order
of frequency: C. p. quinquefasciatus (24 instances), C. tigripes (20),
C. p. pipiens (6), An. coustani and C. univittatus (5), Ae. aegypti (4)
and C. annulioris, C. decens and C. ethiopicus (3). C. p. quinquefasciatus
was the main associate of duttoni in water storage containers followed
78 Estud., Ens. e Doc.- 134