Influence of peri-domiciliar environmental conditions in the dispersion and proliferation of phlebotomine sandflies in Parana state, southern Brazil

The results of phlebotomine collections with Falcäo light traps are described. The collections were made in an area of the Mururê farm, in the Terra Boa County, Paraná State, south of Brazil. One trap was installed at the border of a modified primitive forest and seven in animal shelters (poultry sheds and pigsties) distant 10 to 600m from this forest. Of a total of 5,122 phlebotomine 4,046 (79 per cent) were caught in an pigsty 10m from the border of the forest. The dominant species was Lutzomya whitmani. Dispersion of phlebotomine was near to 600m from the border of the forest and suggests that good environmental conditions for effective breeding in peridomiciliary areas in Mururê farm were not found, what explains the rare occurrence of tegumentary leishmaniasis there

[Culicidae of Itaipu lake, in the Paraná river, southern Brazil]. / Culicídeos do lago de Itaipu, no rio Paraná Sul do Brasil.

Mosquito catches were made in Guaíra county, Paraná State, southern Brazil, in the vicinity of Itaipu dam, from January to December 1991. The catches were made with a Shannon light trap and human bait. The Shannon light trap was installed beside the highway that used, formerly, to lead to the Sete Quedas cataracts and the human bait was used in the urban area. Data about the Culicidae fauna were obtained as to predominant species, seasonal variation, time of highest density and affinity with human host. Forty-one species were identified as belonging to the Anopheles, Aedes, Aedomyia, Coquillettidia, Culex, Mansonia, Psorophora and Uranotaenia genera. With the Shannon light trap 21,280 mosquitoes were caught and with human bait 1,010. In the catches made with the Shannon light trap, Coquillettidia shannoni, Mansonia humeralis, Anopheles trianulatus, Aedes scapularis and Anopheles albitarsis accounted for 82.78% of all mosquitoes taken. In the catches made on human bait the highest densities of these mosquitoes occurred between 7 p.m. and 9 p.m. Aedes scapularis, Mansonia humeralis and Anopheles albitarsis represented 91.21% of all mosquitoes caught with human bait. The highest densities of Aedes scapularis, on human bait, were found between 8 p.m. and 9 p.m. and those of Mansonia humeralis and Anopheles albitarsis between 6 p.m. and 7 p.m. Among the genera caught with the Shannon light trap Coquillettidia shannoni, Mansonia humeralis and Anopheles albitarsis were most frequent in April, Anopheles triannulatus in January and Aedes scapularis in February.

[Mosquitos of peri and extradomiciliary environments in the southern region of Brazil]. / Mosquitos de ambientes peri e extradomiciliares na região sul do Brasil.

Mosquitoes were collected on Sonho Real farm, Querência do Norte county, Paraná State, Brazil, using human bait and Falcão traps between June 1989 and May 1990. The fauna composition, monthly density, hours of major density, human attraction and presence of mosquitoes in domestic animal shelters were investigated. 5,923 mosquitoes of the genera Aedes, Aedomyia, Anopheles, Coquillettidea, Culex, Mansonia, Psorophora, Sabethes and Uranotaenia were collected. 33 species of mosquitoes were identified and among them Aedes scapularis, Anopheles albitarsis, Aedomyia squamipennis, Coquillettidea lynchi, Mansonia titillans e Coquillettidea venezuelensis were predominant. All these species were captured mainly on human bait, except Aedomyia squamipennis that was captured in domestic animal shelters. With regard to all the mosquitoes captured (5,923), their major period of activity was between 18 and 19 hours and April was the month of greatest density.

[Phlebotomine behavior in forest and extraforest environments, in an endemic area of American cutaneous leishmaniasis in northern Paraná State, southern Brazil]. / Observações sobre o comportamento de flebotomíneos em ecótopos florestais e extraflorestais, em área endêmica de leishmaniose tegumentar americana, no norte do Estado do Paraná, sul do Brasil.

Between November 1988 and April 1990, 75,637 phlebotomines were captured with the use of Falcão light traps on Palmital farm in the north of Paraná State, Brazil. Fifteen species were represented. The percentage of 95.8% of the insects were captured within the domiciliary area and the remaining 4.2% in the forest environment. The percentage of 62 were captured in one single Falcão light trap installed in a henhouse, where Blancasmya migonei predominated. In all the other traps Psychodopygus whitmani was predominant. B. migonei, P. whitmani, Pintomyia pessoai, Pintomyia fischeri and Psychodopygus intermedius are highly significant vectors of American cutaneous leishmaniasis and represented 93.8% of all phlebotomines captured with 10 Falcão light traps. The monthly densities of these insects were obtained from one Falcão light trap installed in a henhouse and increased especially in the warmer and more humid months. In the forest environment the phlebotomines were captured principally in traps installed about 10 meters above the ground and P. whitmani, B. migonei, P. intermedius, Brumptomyia brumpti, Psychodopygus monticola and P. pessoai were the dominant species. The need for information about the epidemiology of American cutaneous leishmaniasis calls for further investigation with a view to clarifying the implications of the relationship between the phlebotomines and domestic animals in the Leishmania cycle of transmission in domiciliary areas.

[Adult culicidae captured in the southern region of Brazil]. / Nota sobre culicídeos adultos coletados na região sul do Brasil.

During the period from September 1988 to April 1990, mosquitoes were captured using Shannon light trap and Falcão light traps, in Terra Boa county, in the north of Paraná State, Brazil. The Shannon trap was installed in the outlying modified forest and Falcão traps were installed in the modified forest and domiciliary areas. The prevalence of species was verified and the methods of capture compared.

[Phlebotomines in an area of transmission of tegumentar leishmaniasis in the northern region of Parana State, Brazil: seasonal variation and nocturnal activity]. / Flebotomíneos em área de transmissão de leishmaniose tegumentar na região norte do Estado do Paraná-Brasil: Variação sazonal e atividade noturna.

In two years of phlebotomine captures in a modified forest an appreciable decrease in the size of this insect population has been observed when compared to previous data from the same locality. The captures with the Shannon light trap were made in the outlying forest of Palmital farm in Terra Boa county, Parana State, Brazil. The predominant species were Lutzomyia withmani, Lutzomyia migonei, Lutzomyia intermedius e Lutzomyia fischeri. These insects were active from 6 p.m. to 6 a.m. and the period of greatest activity varied according to the species. These species' densities were higher in the summer and autumn months. Environmental modifications may have influenced the observed changes in phlebotomine behavior.