Numerous sand fly species have been reported in Lençóis Maranhenses National Park (LMNP) in Northeast Brazil, including important Leishmania vectors, making the park an endemic area for tegumentary ...and visceral leishmaniasis. We evaluated sand fly abundance monthly over 7 years, correlating it with environmental variables and monthly tourist numbers in LMNP. Sand fly species were observed throughout the year, with Lutzomyia longipalpis Lutz & Neiva and Nyssomyia whitmani Antunes and Coutinho (Diptera: Psychodidae) being the most abundant species, especially from April to June. In addition to seasonal abundance patterns, Lu. longipalpis showed increasing abundance throughout 2013 until April 2014, whereas Ny. whitmani exhibited a consistent increase throughout the study period. Redundancy analysis indicated that monthly sand fly abundances increased with humidity but decreased with mean temperature and wind speed. Ecotourists mainly visit the park from May to September when interdune lagoons are full, coinciding with high-frequency vector activity during the rainy months (May-June). Tourists also visit in January and February during school holidays, when the rains begin and sand fly abundance increases, and in July, when sand fly abundance decreases. To date, no instances of infected tourists have been recorded, likely because visits to LMNP occur during the day when sand flies are inactive. However, there is a potential risk of vector exposure if tourists engage in nighttime cultural visits to villages around the park, where leishmaniasis cases occur annually.
The richness and abundance of sand fly species were studied in northeastern Brazil in areas of leishmaniasis transmission. The study was carried out in two forest areas with different deforestation ...times for agricultural and livestock activities: one modified by long-term settlement (more than 50 years of occupation) and another less impacted by short-term settlement (10 years). The sand flies were captured with CDC light traps from 18:00 to 06:00 for three consecutive nights, once a month, from May, 2012 to April, 2014. The study captured 21,708 specimens and also 33 species of Lutzomyia and two of Brumptomyia. Species richness and abundance were higher in the more conserved area of short-term occupation (31 species; 61.7%) than in the more degraded area with long-term occupation (17 species; 38.3%). In the most conserved area, the species richness was higher in the forest fragment than in the rural settlement, whereas in the degraded area the richness was higher in the peri-domicile than in the forest. The diversity was higher in the degraded area forest. There were significant statistical differences when comparing the means of total abundance with the intra-domicile, peri-domicile, and forest environments. The average abundance was statistically higher in the peri-domicile compared to the forest (p = 0.009), but there were no statistically significant differences between intra-domicile-peri-domicile (p = 0.11) and forest-intra-domicile (p = 0.87). In conclusion, a change in vegetation cover negatively affects the richness and abundance of sand flies in the natural environment.
Biting midges of the genus Culicoides are small insects associated with the transmission of several pathogens, which requires the correct identification of the species, for implementation of ...effective strategies against these insects. However, many species are difficult to identify only by morphological characters. Therefore, the use of molecular methods can help in the taxonomy and systematics of this group. Here, the DNA barcode approach was evaluated for nine species of Culicoides from the State of Maranhão, Brazil. We generated 39 sequences from a 476 bp (base pairs) fragment of the cytochrome c oxidase subunit I (COI) mitochondrial gene. To assess the usefulness of COI barcodes for the identification of these species, paired genetic distances from intra and interspecific comparisons and phylogenetic trees were generated in MEGA and RAxML/BEAST softwares, respectively. In addition, species delimitation was performed using the PTP, GMYC, and ABGD algorithms. The intra and interspecific genetic distances showed a clear distinction between them, demonstrating that, for the taxa studied, there can hardly be ambiguous identifications with barcodes. In the same sense, the phylogenetic reconstruction resulted in well-supported clades for all morphospecies analyzed.
Sand flies are very common in the region of Lençóis Maranhenses National Park, an important tourist attraction in Brazil. However, the role of some species and their relative importance locally in ...Leishmania Ross 1903 transmission is unclear. The objective of this study was to identify Leishmania infection in phlebotomine sand flies collected around the Lençóis Maranhenses National Park, an important conservation area and popular international/national tourist destination with a high incidence of leishmaniasis. Sand flies were collected in peridomiciliary areas on the tourist route from September 2012 to August 2013. The captured females were subjected to molecular analyses for the detection of Leishmania DNA. Sand flies were infected with four Leishmania species: Leishmania (Viannia) braziliensis (Vianna, 1911) was found in Lutzomyia whitmani (Antunes and Coutinho, 1939) (2.1%) and Lutzomyia longipalpis (Lutz and Neiva, 1912) (1.7%); Leishmania (Leishmania) infantum (Nicole, 1908) infected Lutzomyia wellcomei (Fraiha, Shaw, and Lainson, 1971) (20%), Lutzomyia sordellii (Shannon and Del Ponte, 1927) (4.3%), Lu. longipalpis (3.7%), and Lu. whitmani (0.8%); Leishmania (Leishmania) amazonensis (Lainson & Shaw, 1972) was found in Lu. whitmani (0.58%), while Leishmania (Viannia) lainsoni infected Lutzomyia evandroi (Costa Lima and Antunes, 1936) (3.4%), Lu. longipalpis (1.06%), and Lu. whitmani (0.29%). The occurrence of these parasites requires control measures to reduce the incidence of cutaneous leishmaniasis and to contain a possible epidemic of visceral leishmaniasis, the most severe form of the disease.
Biting midges are of interest to public health because they play an important role as vectors of disease-causing pathogens, as well as being a biting nuisance to humans and domestic animals. Although ...these insects are common in mangrove areas, they have not yet been studied in this ecosystem in the state of Maranhão (MA), Brazil. The objective of this study was to characterize the Culicoides community structure found in a mangrove swamp and verify if the use of vertebrate feces as bait interferes with their composition, richness, abundance, or seasonality. CDC light traps with vertebrate (chicken, ox, control, donkey, capuchin monkey and pig) feces baits were used to capture biting midges in a mangrove area of the Island of São Luís, MA. A total of 4,087 individuals representing 22 species of Culicoides were captured, the most abundant being C. (Oecacta) furens Poey (23.46%), C. (gr. Fluviatilis) leopoldoi Ortiz (21.58%), C. (Hoffmania) ignacioi Forattini (16.98%), C. (Hoffmania) maruim Lutz (13.85%), C. (Diphaomyia) iriartei Fox (10.57%), C. (Hoffmania) insignis Lutz (7.07%), and C. (gr. Limai) limai Barreto (3.03%). Species richness and abundance were higher when baits of capuchin monkey (15 species; 26.84% of the individuals) and pig (15; 25.3%) feces were used. The least attractive baits were donkey (12 species; 9.3%) and ox (nine species; 11.52%) feces. Biting midges were more abundant in the rainy season (67%), but richness was higher in the dry season (19 species). These results show that vertebrate feces may serve as olfactory cues and increase the attraction of biting midges to traps.
Biting midges are widespread in Brazilian natural ecosystems. However, deforestation and other activities that impact the environment are reducing natural habitats where biting midges proliferate. ...The objective of this study was to verify whether there is variation in the composition, richness, abundance, and seasonality of biting midges between wild and rural environments, in a forest area with intense deforestation. Biting midges were captured using 6 traps installed at an average height of 1.5 m in the peridomicile, intradomicile, and deciduous seasonal forests, once a month from May 2012 to April 2013. In total, 2,182 specimens of 13 species of the genus Culicoides were captured. Species richness was similar in the intradomicile (13 species), forest (12), and peridomicile (11), but species diversity was greater in the peridomicile (H' = 0.803) compared with the intradomicile (H' = 0.717) and forest (H' = 0.687). The order of species dominance varied between the forest (Culicoides paucienfuscatus Barbosa > Culicoides leopodoi Ortiz > Culicoides foxi Ortiz > Culicoides ignacioi Forattini) and peridomicile + intradomicile habitats (C. paucienfuscatus > C. foxi > C. filariferus Hoffman > C. ignacioi). The activity of these dipterans was strongly influenced by meteorological variables, as biting midges are predominant in the rainy season (80.7% of specimens), when higher rainfall, relative humidity, and lower temperatures prevail. The abundance of biting midges was higher in the peridomicile + intradomicile (83.7% of specimens) compared with the degraded forest (16.3%), a result that reflects the loss of forest habitat due to intense and progressive deforestation.
The Lençóis Maranhenses National Park, located in Maranhão, Brazil, is a region of exceptional beauty and a popular tourist destination. The adjoining area has suffered from the impact of human ...activity and, consequently, has experienced outbreaks of leishmaniasis. This study aimed to evaluate the composition, abundance, species richness and seasonal distribution of sand flies in the region and to determine the constancy of the insect population.
The survey was conducted at three sites located in the municipalities of Barreirinhas and Santo Amaro between September 2012 and August 2013. Sampling was performed monthly using automatic light traps installed 1.5 m above the soil adjacent to 13 randomly selected rural dwellings. At each site, one trap was placed in the peridomicile near to animal enclosures and another (extradomicile) at 500 m from the peridomicile.
A total of 4,474 individual sand flies were collected over the year with the highest abundance recorded during the rainy season (December to June). Nine species were collected: L. whitmani, L. longipalpis, L. lenti, L. sordellii, L. evandroi, L. flaviscutellata, L. wellcomei, L. termitophila and L. intermedia. Although peridomiciliary and extradomiciliary environments presented similar species richness, the Shannon diversity index was significantly lower in the former (H' = 2.4) compared with the latter (H' = 4.98). Lutzomyia whitmani and L. longipalpis were the most abundant species and were classified as constant (constancy index, CI = 100%) along with L. lenti (CI = 58.3), L. evandroi (CI = 58.3) and L. sordellii (CI = 66.7). The remaining four species presented CI values between 25 and 50% and were considered accessory.
The present results confirm the present of L. whitmani and L. longipalpis in the peridomicile of houses in Lençóis National Park. The abundance of these species could explain, respectively, the endemicity of cutaneous leishmaniasis and sporadic cases of visceral leishmaniasis in the study area. However, in the case of cutaneous leishmaniasis, the presence of other sand fly vectors (in addition to L. whitmani) cannot be neglected. Finally, this study emphasizes the need for a more effective and permanent supervision to control the expansion of these vectors and leishmaniasis outbreaks.
The aim of this study was to investigate whether temperature, rainfall, and humidity influence the annual distribution of Culicoides Latreille 1809, species abundance and richness in rural areas on ...São Luís Island in the state of Maranhão, Brazil. Biting midges were collected in housing for domestic animals in the peridomestic areas of 10 homes. A CDC light trap was installed in each peridomestic area from 6:00 p.m. to 6:00 a.m. once a month for 12 mo. In total, 23,633 individuals belonging to 26 Culicoides species were captured. The most abundant species were Culicoides diabolicus Hoffman, 1925 (27.43%), C. ignacioi Forattini, 1957 (25.9%), C. flavivenulus Costa Lima, 1937 (15.53%), C. insignis Lutz, 1913 (10.66%), C. filariferus Hoffman, 1939 (6.21%), C. boliviensis Spinelli & Wirth, 1984 (6.07%), C. foxi Ortíz, 1950 (2.83%), and C. leopoldoi Ortíz, 1951 (2.54%). Species richness and abundance were greater during the rainy season (24 species; 88% of the individuals) than during the dry season (18 species; 12% of individuals). However, persistent rain on the days the midges were collected or in the preceding 24 h adversely affected abundance. Mean monthly maximum temperature and rainfall on the day of the collection adversely affected Culicoides abundance and richness.
Variation in the structure of phlebotomine (sand fly) communities in forest fragments with different degrees of preservation and human occupation (peridomicile) in eastern Amazonia was studied. We ...identified 43 species of sand flies in our study, of which 38 occurred in both preserved forest areas and in the peridomiciles of short-term settlements, while another 28 species occurred in altered forest fragments and long-term settlements. The composition of the community at each site changed with the type of environment (forest or peridomicile), with the species Lutzomyia evandroi, L. whitmani, L. choti, L. serrana, L. triacantha, L. migonei, L. hirsuta, L. shannoni, and L. brachyphylla accounting for more than 54% of the differences among environments. The quality of the environment exerted a significant influence on the structure of phlebotomine communities, and affected their species composition, richness, and abundance.
Ants are among the insects involved in cadaveric decomposition processes, as they exhibit predatory and necrophagous behavior. Red ants exhibit an aggressive behavior, which impacts carcass ...colonization, accelerates or delays the decomposition rates and potentially confounds interpretation of the post-mortem interval. Here, we estimated the effects of Solenopsis saevissima (Smith) activity on the decomposition rate in domestic pig carcasses. We placed two pig carcasses close to S. saevissima nests, and two other pig carcasses (controls) in other locations 50 m away from the nest. Decomposition processes were delayed by at least three days for carcasses on the nest compared to those without direct exposure to ants. Our results showed that predatory activity of S. saevissima interfered with carcass colonization by scavenger insects, functioning as an ecological barrier to the establishment of immature Diptera. Such results highlight the importance of considering ecological processes that may interfere with mechanisms determining post-mortem intervals.
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