Phlebotomine sandfly responses to carbon dioxide and human odour in the field.

Responses of Lutzomyia sandflies (Diptera: Psychodidae: Phlebotominae) to carbon dioxide (CO2) and human odour were investigated by field experiments in Parana State, southern Brazil. Catches of two predominant species: Lu. intermedia (Antunes & Coutinho) and Lu. whitmani Lutz & Neiva, were compared between traps baited with a human adult or with CO2 emitted at the human-equivalent rate. When the baits were only 40 cm apart, no difference of attractiveness was detected. When baits were separated by 20 m, however, significantly fewer sandflies (44% Lu. intermedia, 46% Lu. whitmani) were trapped with CO2 compared with human bait. This is the first field evidence that anthropophilic sandflies are attracted by human kairomones in addition to CO2. For both species [Lutzomyia intermedia and Lu. whitmani] [corrected], the proportion of human attractiveness attributable to CO2 was significantly more [corrected] for males than females; for Lu. intermedia males human bait was no more attractive than CO2 alone. Gender differences in sandfly olfactory sensitivity are likely to be associated with behavioural differences on the host, where females feed on blood and males find mates. With traps 20 m apart, both Lutzomyia spp. showed roughly linear increased responses (log-log scale) to 0.08-0.55% CO2 equivalent to 0.5-4 humans. This would explain why host size is generally proportional to attractiveness, as observed for other species of phlebotomine sandflies.

Ecology of phlebotomine sandflies (Diptera, Psychodidae) in Brazilian Atlantic Forest.

The phlebotomine sandfly fauna of a primary forest reserve at Morretes (eastern Paraná State) was studied, using CDC-like light traps, one night per month, at canopy and ground level, between April 1995 and March 1996. A total of 3,106 insects were collected, identified as belonging to nine species. Lutzomyia ayrozai and Lu.geniculata were predominant, seven other species also being present. Monthly mean temperature, rainfall and the temperature of the collection night significantly influenced the numbers of Lu. ayrozai while the two first factors influenced the numbers of Lu. geniculata, besides the collected quantities of females of the two species. The influence of the factors on Lu. ayrozai numbers was more immediate than in those of Lu. geniculata. Numbers of both species and of the females of Lu. geniculata collected in different seasons, but not at the different heights, varied significantly. Differences between the behaviour of Lu. ayrozai in Morretes and in other regions could be attributed to environmental differences and/or to regional variations in the species, which could constitute species complexes. Hourly variations of collections were different in the species and seasons.

Ecology of phlebotomine sandflies (Diptera, Psychodidae) in Brazilian Atlantic Forest

The phlebotomine sandfly fauna of a primary forest reserve at Morretes (eastern Paraná State) was studied, using CDC-like light traps, one night per month, at canopy and ground level, between April 1995 and March 1996. A total of 3,106 insects were collected, identified as belonging to nine species. Lutzomyia ayrozai and Lu.geniculata were predominant, seven other species also being present. Monthly mean temperature, rainfall and the temperature of the collection night significantly influenced the numbers of Lu. ayrozai while the two first factors influenced the numbers of Lu. geniculata, besides the collected quantities of females of the two species. The influence of the factors on Lu. ayrozai numbers was more immediate than in those of Lu. geniculata. Numbers of both species and of the females of Lu. geniculata collected in different seasons, but not at the different heights, varied significantly. Differences between the behaviour of Lu. ayrozai in Morretes and in other regions could be attributed to environmental differences and/or to regional variations in the species, which could constitute species complexes. Hourly variations of collections were different in the species and seasons.

A fauna de flebotomíneos de uma reserva de floresta primária em Morretes (leste do Estado do Paraná) foi estudada, utilizando armadilhas luminosas tipo CDC, uma noite por mês, no nível do solo e da copa, entre abril de 1995 e março de 1996. Um total de 3.106 insetos foi coletado. Lu. ayrozai e Lu. geniculata foram predominantes, além de outras sete espécies. A temperatura média mensal, a pluviosidade e a temperatura na noite de coleta influenciaram significativamente as quantidades de Lu. ayrozai e os dois primeiros fatores influenciaram Lu. geniculata, além das quantidades de fêmeas coletadas de ambas as espécies. A influência do aumento dos fatores nas quantidades de Lu. ayrozai foi mais imediata que nas de Lu. geniculata. As quantidades coletadas de ambas as espécies e das fêmeas de Lu. geniculata nas estações, mas não nas alturas, foram significativamente diferentes. As diferenças entre os comportamentos de Lu. ayrozai em Morretes e em outras regiões poderiam ser atribuídas a diferenças ambientais e/ou a variações regionais na espécie, que poderia constituir um complexo de espécies. As variações horárias nas coletas foram diferentes nas espécies e estações.

Influence of altitude, latitude and season of collection (Bergmann's rule) on the dimensions of Lutzomyia intermedia (Lutz & Neiva, 1912) (Diptera, Psychodidae, Phlebotominae).

The influence of altitude and latitude on some structure sizes of Lutzomyia intermedia was noted; several structures of insects collected in higher localities were greater, according to Bergmann's rule. This influence was more remarkable in two localities of the State of Espírito Santo, probably due to greater differences in altitude. Comparing insects from different latitudes, more differences were noted in comparisons of insects from low altitude localities than in those of material from higher altitudes. The small number of differences between insects collected in July and in December does not indicate a defined influence of season and temperature on the size of adults. The possible epidemiological implications of these variations are discussed.

[Geographic distribution of phlebotomine sandflies of the Lutzomyia intermedia (Lutz & Leiva, 1912) complex (Diptera, Psychodidae)]. / Distribuição geográfica de flebotomíneos do complexo Lutzomyia intermedia (Lutz & Neiva, 1912) (Diptera, Psychodidae).

The geographical distribution of Phlebotomine sandflies of the Lutzomyia intermedia complex is presented, based in collections for this study and in personal informations from other workers and bibliography. The subject is discussed, in relation to climate and to altitude and latitude. Lutzomyia intermedia s.s. was found in smaller altitudes and latitudes than Lutzomyia neivai; the last species seems to be better adapted to colder and drier climates than the first.

Distribuição geográfica de flebotomíneos do complexo Lutzomyia intermedia (Lutz & Neiva, 1912) (Diptera, Psychodidae) / Geographic distribution of phlebotomine sandflies of the Lutzomyia intermedia (Lutz & Leiva, 1912) complex (Diptera, Psychodidae)

A distribuição geográfica de flebotomíneos pertencentes a Lutzomyia intermedia s.l. é mostrada, baseada em coletas destes insetos para o presente estudo e em informações da bibliografia e de informações pessoais. O assunto é discutido, em relação ao clima e à altitude e latitude. Lutzomyia intermedia s.s. foi encontrada em latitudes e altitudes menores que Lutzomyia neivai, indicando melhor adaptação desta a climas mais frios e secos.

The geographical distribution of Phlebotomine sandflies of the Lutzomyia intermedia complex is presented, based in collections for this study and in personal informations from other workers and bibliography. The subject is discussed, in relation to climate and to altitude and latitude. Lutzomyia intermedia s.s. was found in smaller altitudes and latitudes than Lutzomyia neivai; the last species seems to be better adapted to colder and drier climates than the first.

[Regional and interspecific variations in the morphology of insects of the Lutzomyia intermedia complex (Diptera, Psychodidae, Phlebotominae)]. / Variações regionais e interespecíficas na morfologia de insetos do complexo Lutzomyia intermedia (diptera, psychodidae, phlebotominae).

INTRODUCTION: Lutzomyia intermedia s. s. and L. neivai, usually considered as belonging to just one species, constitute a complex of species. The measurements of several anatomical structures of specimens of both groups, from Brazil, Paraguay, Argentina and Bolivia were analysed. METHOD: Thirty-nine structures were measured in specimens of both sexes, using a graduated ocular, analysing comparisons by analyses of variance (ANOVA). RESULTS: A significant deviation in the proportions of females and males showing each palpal formula and the influence of the region of origin of the flies were verified. Labrum and maxilary palps were longer in females and Antennomere III was longer of males. Several significant differences in the measurements of wings were noted, most of them greater in females. The proportion of spermathecae with simple heads was significantly greater in L. neivai than in L. intermedia. Significant differences in the length of genital pump and filaments between the species were also noted. DISCUSSION: The variation in the palpal formulae in both sexes show the risk of the use of this formula for the association between specimens of the two sexes. The differences in the lengths of palps and labrum between the sexes could be related to female blood feeding. The possible biological significance of the sexual differential relation length/width of wings is commented on. The different proportions of females of the two species with each spermathecae head shape may help in identification. The differences in the lengths of genital pumps and filaments and the relation between them could help in the identification of males, which is still difficult.

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

[Mosquito (Diptera: Culicidae) ecology in natural and artificial breeding places in rural areas of the northern Paraná State, Brazil. I.--Collections from a riverbed]. / Ecologia de mosquitos (Diptera: Culcidae em criadouros naturais e artificiais de área rural do Norte do Estado do Paraná, Brasil. I.--Coletas ao longo do leito de ribeirão.

The objective of this study is to identify the Culicidae species apt to colonize the waters of a creek with reduced gallery forest in the southern region of Brazil. Captures were performed using a water insect-collecting net. The following species were captured. Aedes crinifer, Aedomya squamipennis, Anopheles fluminensis, An. intermedius, An. albitarsis, An. argyritarsis, An. evansae, An. strodei, An. oswaldoi, An. Triannulatus, Chagasia fajardi, Culex bidens, Cx. group coronator, Cx. eduardoi, Cx. Mollis, Cx. quinquefasciatus, Cx. coppenamensis, Cx. vaxus, Cx. group inhibitor, Cx. intrincatus, Cx. (Melanoconion) sp, Psorophora saeva (?) and Uranotaenia pulcherrima. As for the species which showed the highest frequency rate, the following aspects were studied: population fluctuation, environmental factor correlated with geographic distribution along the area. It was concluded that superficial waters with reduced gallery forest may serve as a refuge for some Culicidae. This fact may contribute to the domiciliation process of the species.

[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.

[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.