Microhabitats de mosquitos (Diptera, Culicidae) em internódios de taquara na Mata Atlântica, Paraná, Brasil

During two consecutive years, from January 1985 to December 1986, a comparative study of mosquitoes preferences for breeding habitat was carried out in the Atlantic Forest of the Serra do Mar, Paraná State, Brazil. To achieve it, 1875 bamboo internodes aligned vertically in live green, bamboo plants Merostachys speciosa Munro and Merostachys sp. were used, in which metabolic water was exuded from the plant itself, and presenting different size/pattern holes at their lateral walls, bored by the local sylvan fauna. Another group of 1200 individual internode traps was used as comparative element, carved out with a transversal cut by a saw, filled with local stream water and held in branches at different heights in the vegetal strata nearby. At both microhabitat types, a total of 17 culicid species was registered. Culex (Microculex) neglectus Lutz, 1904, Cx. (Carrollia) soperi Antunes & Lane, 1937, Sabethes (Sabethes) batesi Lane & Cerqueira, 1942 and Sa. (Sabethinus) melanonymphe (Dyar, 1924)colonized exclusively live plant internodes, while Culex (Microculex) elongatus Rozeboom & Lane, 1950, Cx. (Carrollia) iridescens (Lutz, 1905), Cx. (Carrollia) kompi Valencia,1973and Trichoprosopon (Trichoprosopon) soaresi Dyar & Knab, 1907 bred only in internode traps. The remaining nine species colonized both habitats indistinctly. Quantitatively, was detected the abundance of 60.1% at live green internodes, against 39.9% for internode traps. Concerning the different patterns of bored live internode holes, 40.3% of the total computed specimens were collected in square or rectangular holes, 31.9% in two hole internodes, one minute circular, the other wider, and the remaining 28.8% of specimens distributed in other pattern type internodes. The mosquitoes breeding at these microhabitats fall in the culicid entomofauna specialized at locating and detecting peculiar and propitious mesogen conditions for breeding purposes.

Imaturos de mosquito (Diptera, Culicidae) de áreas urbana e rural no norte do Estado do Paraná, Brasil

The results of larval collections of mosquitoes from artificial containers and natural breeding at urban and rural areas carried out at Sertaneja, northern State Paraná, Brazil, from February to April, 1995, are presented. Among the 4534 immature forms collected, belonging to 21 species or species-groups, the species with higher density were Aedes aegypti (Linnaeus, 1762), Aedes albopictus (Skuse, 1894), Culex quinquefasciatus Say, 1823 and Limatus durhami Theobald, 1901.

Uma estação biológica para o estudo dos mosquitos e dos outros animaes silvestres relacionados com a febre amarela

The outbreak of the jungle or forest yellow fever, through the adapta¬tion, quite recently of the yellow fever virus o the forest mosquitoes, brou¬ght the necessity of ecological researches on hese mosquitoes, as well as on the wild animals they bite, some of them being susceptible to the desease. This has been done by the special yellow fever Service of the State of Sao Paulo, in a special Biological Station in Perús, São Paulo, which has been built in the midst of the jungle. This station was made with plain materials, and covered with straw, but was confortable enough for the technical work, i nthe early months of 1938. During the months in which the investigations were being carried on, the following interesting results were obtained: 1. As we have already pointed out in other places, the forest mosquitoes biting us during daytime, are always new born insects, having not yet sucked blood, as it is the general rule with all mosquitoes, and therefore also, with the anopheles and stegomyia, and this explains why nobody gets malaria or yellow fever, transmitted by anofeles or by aedes aegypti during the day. We think therefore, the jungle yellow fever, got during daytime is not due to the infected jungle or forest mosquito biting, but to infection through the human skin coming into close contact with tre virus, which the forest mosquitoes lay with their dejections, on the leaves of the trees where they remain sitting du¬ring the day. 2. As it is the rule with anopheles, stegomyia and other mosquitoes, the insects once having sucked blood, take nocturnal habits and, therefore, bite us, only during the night, so it happens with the forest mosquito, and insects with developped eggs and blood in stomach have been caught within the sta¬tion house, during the night. During the day, these mosquitoes do not bite, but remain quite still on the leaves of the trees, in the damp parts of the woods. 3. Jungle or forest mosquitoes can easely bite wild animals, some with more avidity then ethers, as it has bee npointed out to the opossum (didei-phis) and other animals. They also bite birds having very thin skin and only exceptionally, cold bloods animals. 5. Is has hot been possible to ascertain how forest mosquitoes are able to live, from onde season to another, through winter, when temperature drops near and even below zero. They have not been found in holes of the terrain, of trees and of animals, as it is the rule in cold countries. During winter, in the forest, it is possible to find larvs in the holes of bambus and trees full of water. As wild animals do not harbour the yellow fever virus for a long time in their body, it is diffcult to explain how the desease lasts from one season to another. Many ecological features on the mosquito, remains yet to be explained and therefore it in necessary to go on with the investigations, in bio¬logical stations, such as that one built up in Perús, São Paulo.

Atividades da estação biológica de Perús

The author who was appointed entomologist of the Biological Station in Perus, São Paulo, describes in this paper, the kind of work he has been doing there. He begins with a description of the organization of the Station and of the routine work as it was daily carried on there, by himself and his staff, during nearly 6 months. During the day as well as during the night, captures of jungle were made in the forest and the same was done by night, in the Station House chiefly when the athmosphere was damp, just before, during, or after a rain. There was also an intensive search for foci of mosquitoes' larves in the bromelias, in holes, in trees and in the soil. The larves found in these breeding places were brought to a larvarium established in the forest in a place close to the station where they were bred in holes of bambus which were very suitable for them. During daytime, only new hatched mosquitoes have been captured, but during the night it has been possible to catch, inside the Station house, many female mosquitoes, with developped eggs, so confirming Aragão's opinion, that mosquitoes biting during the day are always, newly hatched ones. Some species of Sabetini were captured only inside the Biological Station House, during the night. The habits of the following species were subjected to more accurate investigations. Aedes scapularis, Aedes leucocelaenus, Lutzia braziliae, Culex (Carolia) iridescens, Orthopodomyia albicosta, Goeldia palidiventer, Joblotia compressum, Wyeomyia longirostris, Sabetoides intermedius, Limatus durhami. The conditions of the temperature of the Station, did not permit the authour to obtain breedings of Aedes aegypti in the larvarium of the Station, even during he summer months. A great diminuitions of species of the jungle mosquitoes was observed, from January till June, that is, when temperature gets lower and lower. The author has made the interesting observation that some species of mosquitoes (Joblotia and Limatus), must take a meal of flowers or bee honey before they suck blood. A list of the mosquitoes captured during the months of February to June, in the Station is given.

O virus do mixoma no coelho do mato (Sylvilagus minenses), sua transmissão pelos Aedes scapularis e aegypti

The brazilian wild rabbit (Sylvilagus minensis) is sensible to the virus of the mixomatosis but the desease takes on it a mild character, lasts for long time and generally do not kill the animal. The tumors are generally smaller and less numerous than those of the domestic rabbit, but sometimes there were noted large and flat lesions (fig. 3). The natural infection of the wild rabbit may be quite common not only because many rabbits caught in the country were found to be immune as also because it was found among the animals caught in the country near Rio, one that was infected with mixomatosis. The experimental infection of the Sylvilagus may be easily obtained by cutan, subcutan or conjuntival way and also when a health wild rabbit is placed in the same cage with a sick domestic animal. It is also possible to obtain the infection of the wild and domestic rabbits by the bite of infected blood sucking insects as fleas and mosquitoes. The infected mosquito can transmit the disease 2 or 3 times til 17 days after an infective meal on a sick rabbit. The transmission is a mecanical one and only the proboscis of the insect contains the virus as it was shown by the inoculation of emulsions of the proboscis, thorax and abdomen of the mosquito. Though mecanical this kind of transmission acts as an important epidemiological mean of dissemination of the deseasse and splains the suddendly outbreaks of mixomatosis in rabbits breedings where no new rabbits were introduced since very long time. The transmition of mixomatosis by fleas (Slenopsylla) was at first demonstrated by us, then S. Torres pointed out the capacity of Culex fatigans to transmit the desease and now we have proved that Aedes scapularis and Aedes aegypti were also able to transmit it (Foto 1 and 2). The virus of the mixomatosis (Chlamidozoon mixoma) is seen on the smeavs of the tumors of the wild reabbit with the same morphology, as in the material of the domestic animal.

Aspectos parasitários observados no local inoculado com esporozoitos de Plasmodium Gallinaceum

The following is a summary of the studies made on the development of Plasmodium gallinaceum sporozoites inoculated into normal chicks. Initially large numbers of laboratory reared Aëdes aegypti were fed on pullets heavily infected with gametocytes. Following the infectious meal the mosquitoes were kept on a diet of sugar and water syrup until the appearance of the sporozoites in the salivary glands. Normal chicks kept in hematophagous arthropod proof cages were then inoculated either by bite of the infected mosquitoes or by subcutaneous inoculations of salivary gland suspensions. By the first method ten mosquitoes fed to engorgement on each normal chick and were then sacrificed immediately afterwards to determine the sporozoite count. By the second method five pairs of salivary glands were dissected out at room temperature, triturated in physiological saline and inoculated subcutaneously. The epidermis and dermis at the site of inoculation were excised from six hours after inoculation to forty eight hours after appearance of the parasites in the blood stream and stretched out on filter paper with the epithelial surface downward. The dermis was then curretted. Slides were made of the scrapings consisting of connective tissue and epithelial cells of the basal layers which were fixed by metyl alcohol and stained with Giemsa for examination under the oil immersion lens. Skin fragments removed from normal chicks and from regions other than the site of inoculation in the infected chicks were used as controls. In these, only the normal histological aspect was ever encountered. In the biopsy made at the earliest period following inoculation clearly defined elongated forms with eight or more chromatin granules arranged in rosary formation were found. The author believes these to be products of the sporozoite evolution. Search for transition stages between these forms and sporozoites is planned in biopsies to be taken immediately following inoculation and at given intervals up to the six hour period. 1.) 6 and 12 hour periods. The bodies referred to above found in the first period in great abundance, apparently in proportion to the large numbers of sporozoites inoculated, were perceptibly reduced in numbers in the second period. 2.) 18 hour period. Only one biopsy was examined. This presented a binuclear body shown in Fig. 1, having a more or less hyaline protoplasm staining an intense blue and a narrow vacuole delimiting the cell boundaries. The two chromatin grains were quite large presenting a clearly defined nuclear texture. 3.) 24 hour period. A similar body to that above (Fig. 2) was seen in the only preparation examined. 4.) 60 hour period. The exoerythrocytic schizonts were found more frequently from this period onward. Several such were found no longer to contain the previously described vacuoles (Fig. 3). 5.) 84 hour period. Cells bearing eight or more schizonts were frequently encountered here. That these are apparently not bodies in process of division may be seen in Fig. 4. From this time onward small violet granules similar to volutine grains appeared constantly in the schizont nucleus and protoplasm. These are definitely not hemozoin. The above observations fell within the incubation period as repeated examinations of the peripheral and visceral blood were negative. Exoery-throcytic parasites also were never encountered in the viscera at this time. Exoerythrocytic schizonts searched for at site of inoculation 1, 24 and 48 hours after the incubation period were present in large number at all three times with apparent tendency to diminish as the number within the blood stream increased. Many of them presented the violet granules mentioned above. The appearance of the chromatin and the intensity of staining of the protoplasm varied from body to body which doubtless corresponds to the evolutionary stage of each. This diversity of aspect may frequently be seen in the parasites of the same host cell (Fig. 5.). These findings lend substance to the theory that the exoerythrocytic forms are the link between the sporozoites and the pigmented parasites of the red blood corpuscles. The explanation of their continued presence in the organism after infection of the blood stream takes place and their presence in cases infected by the inoculation blood does not come within the scope of this work. Large scale observations shortly to be undertaken will be reported in more detail particularly observations on the first evolutionary phases of the sporozoite within the organism of the vertebrate host.

Verificação, em condiçoes naturais, da infecção de mais três hematófagos (Anophelineos, Flebótomos e Simulídeos) em leprosos

The A. went last August to the State of Minas Gerais to continue his studies on transmission of leprosy by insects. He selected ten lepers (all L3 cases) for his experiments. It happened in the middle of August, a few day after freezing temperature. Practically there were no day mosquitoes, even near a river where in March there were very many. Bringing the patients to a wood, near the Peixe River (Fish River), at the dawn they were attacked by very many Anopheles, some flebotomus, a few Simulium and very rare Culex scapularis. All these insects became infected, in different degrees, by biting such patients. CONCLUSIONS. 1. Two species of Anopheles (A. albitarsis and A. tarsimaculatus) became strongly infected by Hansen bacilli. 2. By dissection done by Dr. Oliveira Castro were found lepra bacilli in various points of the proboscis of two Flebotomus (F. intermedius) and in their stomachs. 3. By smearing were found lepra bacilli in two specimens of Simulium sp. (probably pertinax). 4. It was confirmed also the verification done last March, at the same Leper Colony, that Phthirius pubis can be also a carrier of lepra bacillus. 5. There was confirmed also natural infection of nymphs of Amblyomma cajennense in lepers. Dr. Oliveira Castro is dissecting the Anopheles to locate the bacilli in their organisms and he started, with the cooperation of the Director of Colonia Santa Fé, Dr. José Mariano, attenpts to re-infect a group of negative-nerve cases of leprosy with infected mosquitoes.

Os anofelinos do sub-gênero kerteszia em relação à distribuição das bromeliáceas em comunidades florestais do município de Brusque, Estado de Santa Catarina

The present work is part of the studies realized under the authority of the National Service of Malaria (Brazil), with the collaboration of scientists of the Oswaldo Cruz Institute, in some forests of the southern part of Brazil.This is the first of a series and its subject is the development of the Anopheles mosquitoes of the kerteszia in water collected in Bromeliaceae leaves. The ecology of Bromeliaceae was studied in a previous work. The botanical material was classified by specialists from several botanical institutions from Europe and the United States of America. The most important ecological relations of the “bromeliad-kerteszia” problem were presented through four indices: 1st Positivity index – Relative frequency of bromeliad with watery forms in the bromeliad examined. 2nd Larval index – Mean number of watery forms in the positive bromeliad. 3rd Ovoposition index – Product of the Positivy index by the Larval index. 4th MK index – Product of the Ovoposition index by the total number of bromeliad, positive or not, in a unity of area (1.000 m²). The capture of flying forms in relation to the relative humidity was also studied. From the several forests of the Brusque region we have selected one community of each type, which were the most representative forests in Southern Brazil. Conclusions on the “bromeliad-kerteszia” problem – From a general point of view only a few factors are really important and these are listed below: 1°) The volum of water on the bromeliad. 2°) The level where the bromeliad is fixed. 3°) The number of bromeliad in unity of area. The distribution of microclimas in the forest through the considered levels has a direct influence on the species of subgenus Kerteszia (qualitative influence) and an indirect influence through the ecological distribution of the more frequent bromeliad with best qualities as biotope for the watery forms (qualitative influence). The MK index is roughly proportional to the square of half the total number of Bromeliaceae in a certain type of forest. Then the MK index would be a certain function of the ecological type of the forest and of the total number of bromeliad in a unity of area. MK approximately α x (x/10)² . x = n° of bromeliad in a unity of área (1.000 m²); α = qualitative factor. It would be interesting to see if this proportion is maintained when we have examined a greater number of forests of different types.

Plancto e hidrobiologia sanitária de tanques tropicais com dáfnias e rotíferos

The engineers of the modern University City are constructing a graceful bridge, named PONTE OSWALDO CRUZ, that crosses a portion of the Guanabara Bay (Fig. 1). The work at west pillar stopped for 3 years (The concret structure in Est. 1). As it will be seen from n.º 1 — 5 of the fig. 1, Est. I, the base of the structure will have five underground boxes of reinforcement, but, to-day they are just like as five uncovered water ponds, until at present: May 1963. (Est. I — fig. 3, n.º 3 — pond n.º 3; A. — old level of the water; B.— actual level of the water; c.— green water; E.— mass of bloom of blue algae Microcystis aeruginosa). Soon after SW portion, as 5 cells in series, of the pillar abutments, and also the NE portion nearly opposite in the Tibau Mount will be filled up with earth, a new way will link Rio City and the University City. We see to day Est. I, fig. 1 — the grasses on the half arenous beach of the Tibau Point. These natural Cyperaceae and Gramineae will be desappear because of so a new road, now under construction, when completed will be 33 feet above the mean sea level, as high as the pillar, covering exactly as that place. Although rainfall was the chief source of water for these ponds, the first water (before meterorological precipitations of whatever first rain it might fall) was a common tap water mixed with Portland Cement, which exuded gradually through the pores of the concret during its hardenning process. Some data of its first cement water composition are on the chemical table, and in Tab. n.º 4 and "Resultado n.º 1". The rain — receiving surface of each pond were about 15 by 16 feet, that is, 240 square feet; when they were full of water, their depth was of 2 feet 3", having each pond about 4,000 gallons. Climatic conditions are obviously similar of those of the Rio de Janeiro City: records of temperature, of precipitation and evaporation are seen on the graphics, figs. 2, 3, 4. Our conceptions of 4 phases is merely to satisfy an easy explanation thus the first phase that of exudation of concrete. We consider the 2nd. phase formation of bacterian and cyanophycean thin pellicel. 3rd. phase - dilution by rains, and fertilisation by birds; the 4th phase - plankton flora and fauna established. The biological material arrived with the air, the rains, and also with contaminations by dusts; with big portion of sand, of earth, and leaves of trees resulted of the SW wind actions in the storming days (See - Est. I, fig. 3, G. - the mangrove trees of the Pinheiro Island). Many birds set down and rest upon the pillar structure, its faeces which are good fertilizers fall into the ponds. Some birds were commonly pigeons, black ravens, swallows, sparrows and other sea mews, moor hens, and a few sea birds of comparatively rare occurence. We get only some examples of tropical dust contaminated helioplankton, of which incipient observations were been done sparcely. See the systematic list of the species of plankters. Phytoplankters - Cyanophyta algae as a basic part for food of zooplankters, represented chiefly by rotiferse, water-fleas Moinodaphnia and other Crustacea: Ostracoda Copepoda and Insecta: Chironomidae and Culicidae larvae. The polysaprobic of septic irruptions have not been done only by heating in summer, and, a good reason of that, for example: when the fifth pond was in polysaprobic phase as the same time an alike septic phase do not happened into the 3rd. pond, therefore, both were in the same conditions of temperature, but with unlike contaminations. Among the most important aquatic organisms used as indicatiors of pollution - and microorganisms of real importance in the field of sanitary science, by authorities of renown, for instance: PALMER, PRESCOTT, INGRAM, LIEBMANN, we choose following microalgae: a) The cosmopolite algae Scenedesmus quadricuada, a common indicator in mesosaprobio waters, which lives between pH 7,0 and it is assimilative of NO[3 subscripted] and NH[4 subscripted]. b) Species of the genus Chlamydomonas; it is even possible that all the species of theses genus inhabit strong-mesosaprobic to polysaprobic waters when in massive blooms. c) Several species of Euglenaceae in fast growing number, at the same time of the protozoa Amoebidae, Vorticellidae and simultaneous with deposition of the decaying cells of the blue algae Anacystis cyanea (= Microcystis) when the consumed oxygen by organic matter resulted in 40 mg. L. But, we found, among various Euglenacea the cosmopolite species (Euglena viridis, a well known polysaprobic indicatior of which presence occur in septic zone. d) Analcystis cyanea (= M. aeruginosa) as we observed was in blooms increasing to the order of billions of cells per litter, its maximum in the summer. Temperatures 73ºF to 82ºF but even 90ºF, the pH higher than 8. When these blue algae was joined to the rotifer Brachionus calyflorus the waters gets a milky appearance, but greenished one. In fact, that cosmopolite algae is used as a mesosaprobic indicator. Into the water of the ponds its predominance finished when the septic polysaprobic conditions began. e) Ankistrodesmus falcatus was present in the 5th pond from 26the. April untill the 26th July, and when N.NH[4 subscripted] gets 1.28 mg. L. and when chlorinity stayed from 0.034 to 0.061 mg. L. It never was found at N.NH[4 subscripted] higher than 1 mg. L. The green algae A. falcatus, an indicatior of pollution, lives in moderate mesosaprobic waters. f) As everyone knows, the rotifer eggs may be widely dispersed by wind. The rotifer Asplanchna brightwelli in our observation seemed like a green colored bag, overcharged by green cells and detritus, specially into its spacious stomach, which ends blindly (the intestine, cloaca, being absent). The stock of Asplanchna in the ponds, during the construction of the bridge "PONTE OSWALDO CRUZ" inhabits alkaline waters, pH 8,0 a 8,3, and when we observed we noted its dissolved oxygen from 3.5 to 4 mg. L. In these ponds Asplanchna lived in 0,2 P.PO[4 subscripted]. (Remember the hydobiological observations foreign to braslian waters refer only from 0.06 to 0,010 mg. L. P.PO[4 subscripted]; and they refer resistance to 0.8 N.NH[4 subscripted]). By our data, that rotiger resist commonly to 1.2 until 1.8 mg. L.N.NH[4 subscripted]; here in our ponds and, when NO[2 subscripted] appears Asplanchna desappears. It may be that Asplanchna were devoured by nitrite resistant animals of by Culicidae or other mosquitoes devoured by Due to these facts the number and the distribution of Asplanchna varies considerabley; see - plates of plankton successions. g) Brachionus one of the commonest members of class Rotatoria was frquently found in abundance into the ponds, and we notice an important biological change produce by the rotifer Brachonus colyciflorus: the occurence of its Brachionus clayciflorus forms pallas, is rare in Brazil, as we know about this. h) When we found the water flea MOinodaphnia we do not record simultanous presence of the blue algae Agmenellun (= Merismopedia).

Factors influencing the development of Plasmodium gallinaceum in Aedes fluviatilis

Aedes fluviatilis is susceptible to infection by Plasmodium gallinaceum and is a convenient insect host for the malaria parasite in countries where Aedees aegypti cannot be maintained in laboratories. In South America, for instance, the rearing of A. aegypti the main vector of urban yellow fever, is not advaisable because of the potential health hazard it represents. Our results of the comparative studies carried out between the sporogonic cycle produced with two lines of P. gallinaceum parasites into A. fuviatilis were as follows. As proved for A. aegypti, mosquito infection rates were variable when A. fluviatilis blood-fed on chicks infected with and old syringe-passaged strain of P. gallinaceum. Oocysts developed in 41% of those mosquitos and the mean peak of oocyst production was 56 per stomach. Salivary gland infections developed in about 6% of the mosquitos. The course of sporogony was unrelated to the size of the inoculum administered to chicks or to the route by which the birds were infected. The development of infected salivary glands was unrelated to oocyst production. Sporogony of P. gallinaceum was more uniform when mosquitos blood-fed on chicks infected with a sporozoite-passaged strain. Oocysts developed in about 50% of those mosquitoes and the mean peak of oocyst production was 138 per stomach, with some individuals having as many as 600-800 oocysts. Infected salivary glands developed in a mean of 27% of the mosquitos but, in some batches, was a high as 50%. Patterns of salivary gland parasitism were similar to those of oocyst production. The course of sporogony of P. gallinaceum in A. fluviatilis is analized in relation to degree of parasitemia and gametocytemia in the vertebrate host.

Bionomia de mosquitos (Diptera: Culicidae) em áreas da Mata Atlântica no município de Itaguaí, estado do Rio de janeiro, Brasil: I. Frequência intra, peri e extradomiciliar

Along 24 consecutive months, from January 1984 to December 1986, mosquito captures were performed in a rural area of said municipality. Aiming to evaluate the comparative frequency of the mosquito species inside houses and in the immediate vicinity and far from houses, the captures were made in two types of domiciles - one permanently and the other only sporadically inhabited - as well as in surrounding woods. Variations in temperature, relative humidity and rainfall were locally recorded. A tendency for domiciliation became evident by the presence of Aedes scapularis in the human domiciles, mainly in those permantely inhabited. Culex quinquefasciatus showed to be adapted to live with humans also in rural areas, in which, in some instances, insecticides had to be used to keep in under control. Such observations, mainly in terms of Ae. scapularis, reinforce the possibility of those mosquitoes, under favourable conditions, becoming carries of arboviroses to humans in rural environments.

Os mosquitos (Diptera: Culicidae) do campus ecológico da UFMG, Belo Horizonte, Minas Gerais

In a small forest of 4ha placed inside the Ecologic Campus of Federal University of Minas Gerais, Belo Horizonte, were made captures of mosquitoes each fifteen days (during the day and the night) in a complete year: March 1988 to February, 1989. The daylight captures were made on human bait and the night captures were made with New Jersey trap. Sixty one captures were made, yielding 497 specimens of 15 species.

Observations on the distribution of anophelines in Suriname with particular reference to the malaria vector Anopheles darlingi

A study was made on the distribution of anophelines in Suriname with special emphasis on the principal malaria vector Anopheles darlingi and on the occurrence of other possible vector species. Peridomestic human bait collections of adult mosquitoes and collections of larvae were made in many localities with a recent history of malaria transmission. Stable population of An. darlingi were only found in the interior, south of the limit of tidal influence, due to year-round availability of breeding habitats in quietly sunlit places in flooded forest areas and along river banks. In the area with tidal movement of the rivers, breeding is limited to flooded areas in the west season. Anopheles darlingi was only incidentally collected in low densities. In the interior, malaria transmission occurred in all places where An. darlingi was found. The absence of malaria transmission along the Upper Suriname River could be explained by the absence of An. darlingi. In the malaria endemic areas, An darlingi was the most numerous mosquito biting on man. In the tidal region, malaria outbreak are infrequent and might be explained by the temporary availability of favourable beeding habitats for An. darlingi. However, evidence is insufficient to incriminate an. darlingi as the vector of malaria in this region and the possible vectorial role of other anophelines is discussed.

Culex saltanensis Dyar, 1928: natural vector of Plasmodium juxtanucleare in Rio de Janeiro, Brazil

Searching for the natural vector of Plasmodium juxtanucleare in an enzootic locality: Granjas Calábria (33% of the chickens infected), Jacarepaguá, in Rio de Janeiro, Brazil, 13 comparative captures of mosquitoes were carried out, simultaneously on man (out-doors) and on chiken (in a poultry-yard), between 6 and 9 p.m., from September to March 1989. Culex saltanensis was the most frequent species in captures on chicken, accounting for 41.7% of the mosquitoes collected on this bait, showing to be highly ornithophilic (90% captured on chicken versus 10% on man). Seven specimens of Cx. saltanensis were found naturally infected in granjas Calábria: five with mature pedunculate oocysts and two with sporozoites (on in the haemocoele and one in the salivary glands). These sporozoites porudced an infection by P. juxtanucleare in a chick, which had parasitemia on day 41 after inoculation. One Cx. coronator was found with mature pedunculate oocysts. Culex saltanensis was regarded as primary vector of P. juxtanucleare in Rio de Janeiro for being highly ornithophilic and in enough density to maintain the transmission, having been found with infective sporozoites in its salivary glands, and being susceptible to the parasite and able to transmit experimentally it by the bite.

Astronotus ocellatus (Cichlidae: Pisces) and Macropodus opercularis (Anabatidae: Pisces) as predators of immature Aedes fluviatilis (Diptera: Culicidae) and Biomphalaria glabrata (Mollusca: Planorbidae)

Two fish species, Astronotus ocellatus (Cichlidae) and Macropodus opercularis (Anabatidae) were tested for predacious behavior toward immature mosquitoes (Aedes fluviatili9s, Diptera: Culicidae) and schistosomiasis snail hosts (Biomphalaria glabrata, Mollusca: Planorbidae), in the presence or absence of non-living food and laboratory conditions. A. ocellatus, a species indigenous to Brazil, was a very efficient predator of both organisms (alpha=1,05); M. operculatis, an exotic species, preyed well on immature mosquitoes, but small snails and snail egg-masses were ingested only irregulary. Both fish species seemed to prefer live to non-living food.