Composition and Vertical Stratification of Phlebotomine Sand Fly Fauna and the Molecular Detection of Leishmania in Forested Areas in Rondônia State Municipalities, Western Amazon, Brazil

Trichophoromyia auraensis: evidence for cryptic species and first record in the state of Maranhão, Brazil

Trichophoromyia auraensis (Mangabeira, 1942) (Diptera, Psychodidae, Phlebotominae) has a wide geographic distribution in the western region of the Amazon biome, where it is a putative Leishmania vector. Here, we reported for the first time a population of this species in the Brazilian state of Maranhão, in the eastern Amazon, from which we DNA-barcoded and compared with previously processed specimens from Acre State, in the western Amazon. For this, we analyzed the DNA barcoding fragment (658 bp) of the mitochondrial cytochrome c oxidase subunit I (COI) gene and the nuclear internal transcribed spacer 2 (ITS2) of Trichophoromyia species using phylogenetic gene trees, and species delimitation algorithms. The analyses of COI barcodes showed high values of genetic distance (mean K2P = 5.17) and well-supported clades/MOTUs for the eastern and western populations of T. auraensis, which may indicate a possible complex of cryptic species. The western population of this taxon merged with the close-related sand fly Trichophoromyia velezbernali Posada-López, Galvis and Galati, 2018 from Colombia, which may be associated with the recent speciation history and introgression between these populations. These evidences should be evaluated with a more comprehensive sampling in terms of analyzed populations and molecular markers.

Updating the knowledge of sand flies (Diptera, Psychodidae) in Rondônia State, Brazil

Background

Sandflies are insects important for the transmission cycles of the leishmaniases. Despite being studied since the 1960s in the State of Rondônia (Brazil), several gaps exist regarding our working knowledge of these insects. This study aimed to construct an up-to-date database of sandflies using complementary information from the speciesLink database and the scientific literature, as well as to elaborate integrated abundance maps. We identified 153,155 records of sandflies captured in Rondônia between 1965-2021; after exclusion, 147,258 reports (speciesLink - 3,408, Rondônia studies - 143,850) associated with 15 genera and 140 species were mapped. The most abundant species observed were Psychodopygusdavisi (Root, 1934) (43,818 records), Nyssomyiawhitmani (Antunes & Coutinho, 1939) (12,594), Psychodopyguscarrerai (Barretto, 1946) (11,840), Psychodopygushirsutus (Mangabeira, 1942) (9,676), Nyssomyiaantunesi (Coutinho, 1939) (8,847), Trichophoromyiaubiquitalis (Mangabeira, 1942) (5,505), Psychodopygusgeniculatus (Mangabeira, 1941) (4,644), Pintomyianevesi (Damasceno & Arouck, 1956) (4,140), Trichophoromyiaauraensis (Mangabeira, 1942) (3,579), Psychodopyguscomplexus (Mangabeira, 1941) (2,659), Nyssomyiafraihai (Martins, Falcão & Silva, 1979) (2,504) and Bichromomyiaflaviscutellata (Mangabeira, 1942) (1,418). A total of 20 records of Leishmania detection corresponded to eight sand fly species. The present dataset provides updated information on the distribution of sandflies of Rondônia, including those considered potential vectors of Leishmania, which should prove useful to guide future studies.

New information

The present study provides an extensive dataset built from all studies reporting phlebotomine sandflies in the Brazilian State of Rondônia. Online distribution maps can aid scientists who wish to consult the updated list of sand fly species and view the distribution of these insects, as well as those considered potential vectors of Leishmania. The results of the present study can serve as the basis for future studies on sandflies conducted in the State.

Use of light emitting diodes (LEDs) are effective and useful for sand fly ecoepidemiology studies in an Amazonian environment

One strategy to identify transmission foci is based on vector monitoring, and efficient methods are important for vector control. Our study evaluated different light sources (red, green, ultraviolet, blue, and incandescent light) to capture sand fly in Porto Velho, Brazil. We also evaluated Leishmania and blood meal sources in females. A total of 1,943 individuals were identified in 45 species level-taxa, with Trichophoromyia ubiquitalis (Mangabeira) (n=364), Nyssomyia antunesi (n=241), Bichromomyia flaviscutellata (Mangabeira) (n=222), and Psychodopygus davisi (Root) (n=148) being the most abundant. Incandescent light captured most individuals (n=589), followed by blue (n=471), green (n=452), ultraviolet (n=281) and red (n=150). No significant difference was observed between the species composition and lights (PERMANOVA: Pseudo F = 1.29, p = 0.14, NMDS: Stress 0.18). The Shannon and Simpson indices demonstrated a high diversity captured using all lights. Our data demonstrated that LEDs are alternative devices for sand fly capture, with blue and green LEDs presenting similar results to incandescent light. 53 pools were analyzed, only one pool was positive for kDNA and hsp70 targets [Nyssomyia fraihai (Martins, Falão & Silva)] and identified as Endotrypanum spp., suggesting that other trypanosomatids may circulate in the locality. Choloepus hoffmanni (two-toed sloth) Peters, Homo sapiens Linnaeus, Proechimys gardneri (Gardner's spiny rat) Da Silva, and Tamandua tetradactyla (lesser anteater) (Linnaeus) were blood meal sources identified in females, increasing the knowledge about sources used by these insects.

Trypanosomatids in Phlebotomine Sand Flies (Diptera: Phlebotominae) From Anthropic and Sinantropic Landscapes in a Rural Settlement in the Brazilian Amazon

Trypanosomatids (Kinetoplastida:Trypanosomatidae) protozoa are a diverse group of obligate parasites. The genera Trypanosoma and Leishmania are the most studied because of their medical importance. This work aims to evaluate the effects of anthropization processes on the composition of the phlebotomine sand fly fauna and the natural infection by Trypanosomatids, with emphasis on Leishmania. At all 3,186 sand flies were collected, distributed in 13 genera and 52 species, being Ny. umbratilis the most abundant species. There was no difference in the diversity between canopy and soil environments. The species abundance and richness were higher in the forest environment while species diversity and evenness were highest in the forest edge. The ITS1 region was used by PCR-RFLP to identify the fragment profiles of Leishmania species, followed by genetic sequencing. Here were analyzed 100 pools of female sand flies, being six positive for DNA parasite. PCR-RFLP fragment patterns similar to Endotrypanum sp. were observed in Nyssomyia anduzei, Psychodopygus amazonensis and Lutzomyia gomezi, and those fragments similar to Leishmania (Leishmania) amazonensis were observed in Bichromomyia flaviscutellata. ITS1 sequencing confirmed the presence of Leishmania sp. in Bi. flaviscutellata, and Leishmania (Viannia) naiffi in Ny. anduzei, Psychodopygus amazonensis, and Lu. gomezi. This is the first record of Lu. gomezi and Ps. amazonensis infection by L. naiffi in the State of Amazonas. These results show the trypanosomatid infection in sandflies from different landscapes in a rural settlement, and the finding of species infected with L.(V.) naiffi suggest that they can develop a role in the transmission cycle of leishmaniasis.

Entomological survey of phlebotominae sand flies (diptera: psychodidae) and vector species in the tegumentary leishmaniasis endemic area in eastern brazilian Amazon, Amapá state

Abstract: American tegumentary leishmaniasis is an endemic that has increased considerably in recent decades in the Amazon region, sand flies are the vectors of the transmission of the protozoan that causes leishmaniasis, so the objective of this study was to carry out a survey of the diversity of species and the presence of Leishmania DNA in vectors circulating in three endemic counties for tegumentary leishmaniasis in the eastern Brazilian Amazon (Amapá state, Brazil). Using CDC light traps, a total of 10,773 specimens were collected between February 2019 and February 2020, representing 64 species in 15 genera. The vector specie Nyssomyia umbratilis Ward and Frahia, 1977 was the predominant species (13.20% of the total), being collected in all three counties, followed by Trichopygomyia trichopyga Floch & Abonnenc, 1945 (11.41%), Trichophoromyia ubiquitalis Mangabeira,1942 (9.47%) and Nyssomyia anduzei Rozeboom, 1942 (7.61%). For the identification of Leishmania DNA, 775 pools of unengorged females were used, of which 5 tested positive, 2 of Nyssomya umbratilis Ward & Fraiha,1977, 1 of Nyssomyia anduzei and 2 of Psychodopygus davisi Root,1934, demonstrating a natural total infection rate of 0.64%. This study increases the knowledge of vector diversity, as well as identifying Leishmania spp. in circulation in the eastern region of the Amazon.

Identification of Bloodmeals from Sand Flies (Diptera: Psychodidae) Collected in the Parque Nacional do Viruá, State of Roraima, Brazil

The transmission of pathogens that cause leishmaniases occurs by the bite of female sand flies (Diptera: Psychodidae) in their vertebrate hosts, which makes the identification of their bloodmeal sources an important step for the control and epidemiology of these diseases. In Brazil, the state of Roraima has a great diversity of sand flies, vertebrate hosts, and protozoan Leishmania, but little is known about the host blood-feeding preferences of sand flies. Thus, we evaluated the bloodmeal sources of sand flies collected from their sylvatic habitats in Parque Nacional do Viruá, Roraima. Fieldwork was carried-out between 13th and 18th August 2019 using CDC light traps. Sand flies were slide-mounted and morphologically identified using the head and last segments of the abdomen. Engorged females had their DNA extracted, followed by amplification and sequencing of the cytochrome b (cytb) molecular marker for vertebrates. Sequences were analyzed and compared with those from GenBank using the BLASTn search tool, in addition to the reconstruction of a phylogenetic tree to demonstrate the clustering pattern of these sequences. A total of 1,209 sand flies were identified, comprising 20 species, in which the most abundant were Psychodopygus ayrozai (Barretto and Coutinho) (42.10%) and Psychodopygus chagasi (Costa Lima) (26.22%). Bloodmeal source identification was successfully performed for 34 sand flies, that confirm four vertebrate species, being the most abundant the armadillo Dasypus novemcinctus Linnaeus, 1758 (Cingulata: Dasypodidae).

DNA-based blood meal analysis of Culicoides (Diptera: Ceratopogonidae) species from Jamari National Forest, Southwestern Amazon, Brazil

Culicoides biting midges are insects involved in the transmission of filarial nematodes, protozoans, and viruses. Greater knowledge of Culicoides blood meal sources could improve our understanding of parasite transmission cycles. Our study used molecular tools to evaluate the blood meal sources of Culicoides biting midges from sylvatic environments. This study was conducted in Jamari National Forest, Rondônia, Brazil. Culicoides were captured using HP light traps positioned at ground level (1.5 m above ground) and in canopy (15 m above ground). To identify blood meal sources, females were subjected to DNA extraction and PCR targeting the cytb gene fragment, and the obtained sequences were analyzed and compared with sequences from GenBank. DNA extraction and PCR were performed on 455 Culicoides females, and blood meal sources were identified in 186 females. Thirty Culicoides specimens were collected from the Potosi trail and 156 were collected from the Santa Maria trail. A total of 22 species were captured; all 22 species were collected in canopy (100%) but only three species were collected at ground level (13.6%). The cytb fragment was amplified in 162 of 186 samples. Sample sequencing identified cytb DNA from nine blood-meal sources: Pauxi sp., Psophia viridis, Ramphastos tucanus tucanus, Choloepus didactylus, Choloepus hoffmanni, Tamandua tetradactyla, Ateles chamek, Homo sapiens and Pithecia irrorata. We observed that several different blood meal sources were utilized by a high diversity of Culicoides species. The abundance of Culicoides in the canopy may be related to the fact that the majority of blood meal hosts feed in treetops. We observed that C. (Hoffmania) sp. and C. coutinhoi tend to be more generalist, feeding on a range of mammals and piciform, gruiform and galliform birds. This data improves our knowledge of the feeding profile of biting midges from forest environments and should serve as a future basis for defining zoonotic transmission cycles.

Biting Midges in Jamari National Forest, in the Brazilian Amazon, With 12 New Records of Culicoides Species (Diptera: Ceratopogonidae) for the State of Rondônia

Culicoides biting midges are small hematophagous flies, some species of which transmit pathogens to livestock and humans. In the Brazilian Amazon Basin, Culicoides diversity has remained largely unexamined. Jamari National Forest (JNF) is a conservation area in Rondônia State where research and environmental education are conducted in conjunction with the protection of natural resources, and the recovery of degraded areas. The present study augments our knowledge of Culicoides diversity in JNF. The survey collected 640 individuals from 41 species; 632 individuals were collected by HP light trap and 8 were collected by the BG Sentinel trap. Twelve species are first-time records for Rondônia: Culicoides acotylus Lutz, Culicoides albuquerquei Wirth & Blanton, Culicoides baniwa Felippe-Bauer, Culicoides bricenoi Ortiz, Culicoides brownei Spinelli, Culicoides carsiomelas Wirth & Blanton, Culicoides debilipalpis Lutz, Culicoides forattinii Ortiz, Culicoides ginesi Ortiz, Culicoides profundus Santarém, Felippe-Bauer & Trindade, Culicoides pseudoreticulatus Santarém, Felippe-Bauer & Castellón, and Culicoides spurius Santarém, Felippe-Bauer & Trindade. The most abundant species were Culicoides glabrior Macfie, Culicoides pseudodiabolicus Fox, Culicoides debilipalpis, Culicoides quasiparaensis Clastrier, and Culicoides brownei Spinelli. The present study updates the Culicoides species count in Rondônia to 55, and highlights the importance of JNF as a hotbed for biting midge diversity.

Sand Fly (Diptera: Psychodidae: Phlebotominae) Population Dynamics and Natural Leishmania Infections in Attica Region, Greece

A 2-yr sand fly (Diptera: Psychodidae) seasonality study was performed in Attica Region, Greece, from June 2017 until November 2018, aiming also to detect the presence of Leishmania infection in the collected sand flies. In total, 701 sand flies were collected from urban areas within the Attica Region using BG-Sentinel traps, set weekly in eight fixed sites. Five species were identified morphologically and molecularly, namely Phlebotomus tobbi (Adler and Theodor), which was most the most commonly collected species, followed by P. Neglectus (Tonnoir), P. papatasi (Scopoli), P. simici (Theodor), and Sergentomyia minuta (Rondani). During both survey years sand fly populations peaked in late August to early September. Fifty-nine monospecific pools were examined for Leishmania detection by analyzing the ITS1 nuclear region using both RFLPs and sequencing, seven of which were found positive. Leishmania DNA was identified as L. infantum in six pools (five P. papatasi and one P. tobbi), whereas in one P. papatasi pool Leishmania DNA was identified as L. tropica. This is the first time that L. tropica has been detected in naturally infected sand flies from the Attica Region as well as in central Greece, while previously it has only been detected in sand flies collected from Central Macedonia (Northern Greece).

Vertical stratification of sand fly diversity in relation to natural infections of Leishmania sp. and blood-meal sources in Jamari National Forest, Rondônia State, Brazil

BACKGROUND

Almost 1000 cases of American cutaneous leishmaniasis have been registered yearly in Rondônia State, Brazil. Little is known about the Leishmania transmission cycle (vectors and reservoirs) in the state. This study aimed to evaluate sand fly fauna from two vertical stratification layers in order to identify potential vectors and their blood-meal sources.

METHODS

The study was conducted in Jamari National Forest. Sand flies were collected in the canopy (15 m) and at ground level (1 m) using HP light traps during four months, February, April, August and October, 2018. Insects were identified to the species level, and females were subjected to DNA extraction and PCR targeting minicircle kDNA and hsp70 (for Leishmania detection and species identification), and cytb (to identify blood-meal sources). Exploratory data analysis was used to determine mean of abundance and species richness between stratifications. The hsp70 and cytb sequences were analyzed and compared with sequences from GenBank.

RESULTS

Overall, 68 species were identified from 15,457 individuals. On the Potosi trail, 7531 individuals of 49 species were collected; canopy captures totaled 6463 individuals of 46 species, while ground captures totaled 1068 individuals of 38 species. On the Santa Maria trail, 7926 individuals of 61 species were collected; canopy captures totaled 6136 individuals of 51 species, while ground captures totaled 1790 individuals of 53 species. A total of 23 pools were positive for kDNA (canopy n = 21, ground n = 2). Only two samples were sequenced for hsp70 (both in canopy); one sequence exhibited similarity with Leishmania braziliensis (Lutzomyia davisi pool) and another with L. naiffi (Lu. antunesi pool). The cytb fragment was amplified in 11 of 86 samples. Sample sequencing identified cytb DNA from 5 blood-meal sources: Micrastur gilvicollis, Psophia viridis, Tamandua tetradactyla, Homo sapiens and Choloepus didactylus.

CONCLUSIONS

Sand fly fauna is more diverse in the canopy than at ground level. Factors such as blood-meal sources, resting sites, and abiotic components probably contribute to high abundance in the canopy. Our results reinforce the possibility that Lu. antunesi and Lu. davisi participate in Leishmania transmission in forest environments and may play an important role in transmission from sylvatic to human hosts.

New Records of Phlebotomine Sand Flies (Diptera: Psychodidae) From the Western Brazilian Amazon and the Description of the Female of Pintomyia fiocruzi

An entomological survey was conducted in several localities of Rondônia State, and new records were obtained for seven sand fly species: Evandromyia apurinan Shimabukuro, Figueira & Silva, 2013, Evandromyia carmelinoi (Ryan, Fraiha, Lainson & Shaw, 1986), Micropygomyia echinatopharynx Andrade-Filho, Galati, Andrade & Falcão, 2004, Nyssomyia urbinattii Galati & Galvis, 2012, Pintomyia duckei Oliveira, Alencar & Freitas, 2018, Psathyromyia pradobarrientosi (Le Pont, Matias, Martinez & Dujardin, 2004), and Sciopemyia vattierae (Le Pont & Desjeux, 1992). Herein, we also describe the female of Pintomyia fiocruzi Pereira Júnior, Pessoa, Marivalva & Medeiros, 2019. The female has spermathecae with a detached apical ring similar to the spermathecae of Pintomyia serrana (Damasceno & Arouck, 1949), Pintomyia odax (Fairchild & Hertig, 1961), Pintomyia ottolinai (Ortiz & Scorza, 1963), and Pintomyia robusta (Galati, Cáceres & Le Pont, 1995). Here, we provide characters to separate Pi. fiocruzi from Pi. serrana and Pi. odax. Pintomyia ottolinai has a trans-Andean distribution and Pi. robusta has not been found in Brazil and in our studies, we associated the females found in this study with Pi. fiocruzi males found at the same collection sites. Our findings highlight the importance of entomological fauna surveys and demonstrate the need for taxonomists to study species diversity in Rondônia. This study increases the number of sand fly species recorded in Rondônia to 143.

Increasing putative vector importance of Trichophoromyia phlebotomines (Diptera: Psychodidae)

Despite some phlebotomines being well recognised as vectors of leishmaniasis agents, vector importance of those belonging to the genus Trichophoromyia has not been extensively studied. The present study provides evidence regarding the putative vector role played by some species of Trichophoromyia on leishmanine enzootics, based on literature reports and findings obtained from field experiments conducted in the ecotopes of Pará State, Brazil. The species Th. ubiquitalis, Th. velascoi, Th. auraensis, Th. ininii and Th. brachipyga possess minimal criteria to be included in the list of suspected leishmanine vectors. However, knowledge on man-biting behavior, substantiation of vector competence and determination of epidemiological implications are limited for all of the above mentioned species. Published studies together with present data draw attention to prioritize these phlebotomine species in entomological surveillance programs and studies on experimental susceptibility to Leishmania spp. infection.

Diversity, natural infection and blood meal sources of phlebotomine sandflies (Diptera, Psychodidae) in the western Brazilian Amazon

BACKGROUND

The state of Rondônia (RO) is a hot spot for human cases of cutaneous leishmaniasis. Many sandfly species in RO are putative vectors of leishmaniasis.

OBJECTIVES

This study examines the diversity patterns and the presence of Leishmania DNA and blood meal sources of sandflies in RO.

METHODS

A sandfly survey was performed between 2016 and 2018 in 10 municipalities categorised into three different environment types: (i) Conservation Unit (CUN) - comprised of preserved ombrophilous forests; (ii) Forest Edge (FE) - small forest fragments; and (iii) Peridomicile (PE) - areas around dwellings.

FINDINGS

A total of 73 species were identified from 9,535 sandflies. The most abundant species were Psychodopygus davisi (1,741 individuals), Nyssomyia antunesi (1,397), Trichophoromyia auraensis (1,295) and Trichophoromyia ubiquitalis (1,043). Diversity was the highest in CUN, followed by the FE and PE environments. One pool of Ps. davisi tested positive for Leishmania braziliensis, reinforcing the possibility that Ps. davisi acts as a vector. The cytochrome b (cytb) sequences were used to identify three blood meal sources: Bos taurus, Homo sapiens and Tamandua tetradactyla.

MAIN CONCLUSIONS

Our results demonstrated that sandflies can switch between blood meal sources in differing environments. This study enhances the knowledge of the vector life cycle in RO and provides information relevant to leishmaniasis surveillance.