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

RIBgIR0, H. & RAMOS, ]-[. Cunha -- <strong>Research</strong> o. the tnosquiloes of A.gola -- X
reared females. No breeding dependant upon an inadequate sewage
disposal nor upon stored water for domestic uses was ever observed by
the writers in the Angolan populations of piplens s.s.
The following account, however, refers only to those 20 breeding
places which could be surely confirmed as being of pipiens s.s.
through the examination of genitalia of males reared from larvae.
These 20 breending sites were of three main kinds: ground water (14),
artificial containers (4) and vegetable containers (2). Ground water
breeding places consisted of: river margins (6), open shallow earth
wells (4), vegetated rain-water ground-pools (2), borrow-pits (1) and
crabholes (1). Artificial containers were used by pipiens for breeding as
follows: boats in river margins (2), pottery vase with rain-water (1)
and choked cement drain (1). Breeding in vegetable containers was
recorded in two instances: in a fallen banana leaf with rain-water and
in an old abandoned gourd with rain-water and decaying fallen leaves.
Thus, C. pipiens pipiens seems to be mainly a ground-water breeder
(65 0er cent of the breeding places) though also exhibiting a marked
ability for breeding in small, non-earthy containers, usually of vegetable
origin and not envolved in the stGrage of water for domestic
uses. In other words, from the evidence available. it seems that in
Angola the breeding area of pipiens s.s. shows little or none dependence
upon human activities.
The breeding water was often clean and limpid, usually with emergent
and floating vegetation, though several instances were recorded
of turbid, greenish water full of microscopic green algae and/or with
fallen leaves and vegetable debris. The presumed high organic matter
content of such breeding waters, however, seems to be always of vegetable,
non animal, origin. The pH of ten breeding places ranged from
5.4-7.0, with a mean of 6.4. The chloride content of the water, measured
in three larval biotopes, was 0.82, 2.28 and 9.83 g/1 (NaCl), which
shows some tolerance of pipiens s.s. to brackish water.
In 5 out of the 20 pipiens s.s. breeding places, no other mosquito
larvae were found. 17 Culicines and 2 Anophelines were recorded from
the remaining larval biotopes of pipiens s.s. as associated species.
C. p. quinquefasciatus (confirmed by male terminalia) was the main
associate (7 breeding places, 35 per cent of all confirmed pipiens s.s.
larval biotopes), followed by C. univittatus (3) and C. antennatus, C. decens,
C. duttoni and C. tigripes (2, each). An. coustani, An. listeri,
92 Extud., E.s. e Doc.--134