Popularly known as mosquito-palha, birigui, cangalhinha, tatuquira, asa dura, asa branca or anjinho in Brazil, phlebotomine sandflies (Diptera: Psychodidae) are small insects of great importance in the epidemiology of various diseases, including the leishmaniases, in animals and humans1. Between 1907 and 1940, a total of 33 phlebotomine species were identified in the Americas. Since then, interest in these insects has increased that number dramatically, and approximately 400 new species and subspecies have been described1. Among these, Lutzomyia longipalpis is considered particularly important as the main vector of visceral leishmaniasis. Perfectly adapted to the urban environment, it can also be widely found in forest, transitional and cerrado biomes, reflecting its wide variety of suitable habitats and eclectic alimentary preferences2.
The municipality of Juiz de Fora (21°41′20″S/43°20′40″W) is situated in southeastern Minas Gerais, 283km from the State capital, Belo Horizonte, and canine visceral leishmaniasis is considered endemic in this city3. Juiz de Fora has a humid subtropical climate, a mean annual temperature ranging from 15°C to 24°C and an average annual humidity of 80%. Annual rainfall4 varies between 1,300 and 1,500mm. The urban area includes several remaining areas of Atlantic rainforest. In 2008, the first cases of autochthonous canine visceral leishmaniasis were diagnosed by the Secretaria Municipal de Saúde of Juiz de Fora. However, no research on the local sandfly fauna has been conducted.
The entomological sampling was performed from March to September 2012, during 39 overnight monitoring events held in twelve neighborhoods of the eastern region of the city (Alto Grajaú, Linhares, Nossa Senhora de Lourdes, Parque Burnier/JK, Progresso, Santa Rita, Santo Antônio, São Benedito, São Bernardo, São Dimas, Tiguera and Vila Ideal). With the exception of the São Benedito neighborhood, in which both a peridomestic environment and forest biome site were investigated, one HP light trap5 was set in a peridomestic site for each household surveyed. One point of capture was also placed at the municipal kennel. In total, thirteen traps were installed, with attention given to the presence of bird and/or mammal shelters as well as of banana trees, organic matter accumulation in the soil, humidity, shade and vegetation. The traps were set from 5pm to 8am for three consecutive nights of two weeks per month (except for July, during which the collections were performed in just one week). After screening, the captured sandflies were mounted on slides. The taxonomic identification was conducted according to Young & Duncan6. Samples were sent to the Centro de Pesquisas René Rachou, Fundação Oswaldo Cruz/Belo Horizonte to confirm the identities. The slides were stored in the permanent collection of the Laboratório de Entomologia, Superintendência Regional de Saúde/Juiz Fora.
The locations were georeferenced using a Global Positioning System (GPS), Garmin Model II-12, and imported into a Geographic Information System (GIS) to permit the visualization of their spatial distribution.
As shown in Table 1, a total of 133 phlebotomine sandflies were captured, including 65 (48.9%) males and 68 (51.1%) females, from the forest biome (91.7%) and peridomestic sites (8.3%) surveyed. Eight species of the genus Lutzomyia were captured: Lutzomyia (Psathyromyia) pascalei (Coutinho & Barretto, 1940), Lutzomyia (Psychodopygus) ayrozai (Barretto & Coutinho, 1940), Lutzomyia (Psychodopygus)hirsuta (Mangabeira, 1942), Lutzomyia (Psychodopygus) matosi (Barretto & Zago, 1956) Lutzomyia(Psychodopygus) lloydi (Antunes, 1937), Lutzomyia (Evandromyia) edwardsi (Mangabeira, 1941), Lutzomyia (Evandromyia) sallesi (Galvão & Coutinho, 1939) and Lutzomyia (Lutzomyia) amarali (Barretto & Coutinho, 1940). The most prevalent species was Lu. pascalei (42.9%), followed by Lu. ayrozai (21.1%) and Lu. hirsuta (15%). With the exception of four specimens of the genus Brumptomyia, which were not of interest in this research, all of the captured specimens belonged to the genus Lutzomyia. Furthermore, three specimens of the genus Lutzomyia were damaged and thus could not be identified. These specimens composed 5.3% of the specimens captured and were found in the São Benedito neighborhood (Table 1).
TABLE 1 – Total numbers and percentages of sandflies captured from thirteen sites in the eastern region of the municipality of Juiz de Fora, State of Minas Gerais, Brazil, from March to September 2012, distributed according to species, sex and habitat.
| Species | Peridomestic site | Rainforest biome | Total | |||||||
|---|---|---|---|---|---|---|---|---|---|---|
| males | females | males | Females | |||||||
| n | % | n | % | n | % | n | % | n | % | |
| Lutzomyia amarali | – | – | – | – | – | – | 1 | 1.6 | 1 | 0.7 |
| Lutzomyia ayrozai | 1 | 14.3 | 1 | 25.0 | 17 | 29.3 | 9 | 14.1 | 28 | 21.1 |
| Lutzomyia edwardsi | – | – | 1 | 25.0 | – | – | 1 | 1.6 | 2 | 1.5 |
| Lutzomyia hirsuta | 1 | 14.3 | – | – | 10 | 17.2 | 9 | 14.1 | 20 | 15.0 |
| Lutzomyia lloydi | 5 | 71.4 | – | – | – | – | – | – | 5 | 3.8 |
| Lutzomyia matosi | – | – | – | – | 11 | 18.9 | 9 | 14.1 | 12 | 9.0 |
| Lutzomyia pascalei | – | – | – | – | 17 | 29.3 | 40 | 62.5 | 57 | 42.9 |
| Lutzomyia sallesi | – | – | 1 | 25.0 | – | – | – | – | 1 | 0.8 |
| Lutzomyia sp. | – | – | 1 | 25.0 | 2 | 3.4 | – | – | 3 | 2.2 |
| Brumptomyia sp. | – | – | – | – | 1 | 1.7 | 3 | 4.7 | 4 | 3.0 |
| Subtotal | 7 | 5.3 | 4 | 3.0 | 58 | 43.6 | 64 | 48.1 | – | – |
| Total | 11 | 8.3 | 122 | 91.7 | 133 | 100.0 | ||||
This study covered the eastern region of the City of Juiz de Fora. Figure 1 shows the spatial distribution of the phlebotomine sandflies. All species found were concentrated in a single area of the region surveyed, within the São Benedito neighborhood. Together, the two São Benedito sites accounted for 94.7% of the total number of sandflies captured (126 specimens).
FIGURE 1 – Spatial distribution of sandflies in the municipality of Juiz de Fora, State of Minas Gerais, Brazil. Coverage area of the city showing the sandflies captured in the eastern region from March to September 2012.
No phlebotomine sandflies were captured in seven of the twelve neighborhoods surveyed (Alto Grajaú, Linhares, Parque Burnier/JK, Progresso, Santo Antônio, São Bernardo and São Dimas). Both Lu. lloydi(Nossa Senhora de Lourdes and São Benedito) and Lu. sallesi (Vila Ideal) were found only in peridomestic sites. Lutzomyia amarali, Lu. matosi and Lu. pascalei were found exclusively in the forest biome (São Benedito). Lutzomyia ayrozai, Lu. edwardsi and Lu. hirsuta were captured from both peridomestic sites and the forest site (São Benedito, Santa Rita and Tiguera, respectively).
This study is the first inventory of phlebotomine sandfly fauna held in Juiz de Fora. The species Lutzomyia intermedia, Lutzomyia migonei and Lutzomyia quinquefer have previously been found in this municipality7,8. Therefore, the data obtained in this work add to the available information on the local fauna, identifying eight species of the genus Lutzomyia that have not been previously reported in this city, namely Lu. amarali, Lu. ayrozai, Lu. edwardsi, Lu. hirsuta, Lu. lloydi, Lu. matosi, Lu. pascalei and Lu. sallesi. Notably, none of the formerly reported species were found in the present study, possibly because they were captured at different sites within the city or because of possible changes related to biotic and/or abiotic factors. The most prevalent species captured in the present study (Lu. pascalei) has been shown to be in a process of geographical expansion. Restricted to the northeastern and southeastern regions of Brazil until recently, it has already been found in southern Brazil9,10.
The subgenus Psychodopygus was represented by four species. Some species of this group, i.e., Lu. hirsuta and Lu. lloydi, have been found to be naturally infected with Leishmania in Minas Gerais11,12. Lutzomyia lloydi was found in Juiz de Fora, but at a low frequency.
In this work, the capture sites were chosen based on reports of the occurrence of asymptomatic dogs seropositive for canine visceral leishmaniasis. However, none of the eight Lutzomyia species found is considered of epidemiological importance in the transmission of this disease. In addition, this research showed that within the study area, a more diverse phlebotomine fauna existed in the natural environment than in those environments subject to anthropic impacts, consistent with the data from the literature1. Further surveys will be performed in other areas of the city.
In a recent review, Andrade & Dantas-Torres showed that at least 93 species included in 16 genera of phlebotomine sandflies identified in Brazil have already been found in the State of Minas Gerais13. However, the authors added that many municipalities have not yet been surveyed thoroughly. Thus, our research contributes to the knowledge of the species diversity and spatial locations of the phlebotomine sandfly fauna in Minas Gerais as well as to future studies of the behavior of these insects.
