Species Of Phlebotomine Sandflies Research Articles

Comparative genomics uncovers the evolutionary dynamics of detoxification and insecticide target genes across 11 phlebotomine sand flies.

Sand flies infect more than one million people annually with Leishmania parasites and other bacterial and viral pathogens. Progress in understanding sand fly adaptations to xenobiotics has been hampered by the limited availability of genomic resources. To address this gap, we sequenced, assembled and annotated the transcriptomes of 11 phlebotomine sand fly species. Subsequently, we leveraged these genomic resources to generate novel evolutionary insights pertaining to their adaptations to xenobiotics, including those contributing to insecticide resistance. Specifically, we annotated over 2,700 sand fly detoxification genes and conducted large-scale phylogenetic comparisons to uncover the evolutionary dynamics of the five major detoxification gene families: Cytochrome P450s (CYPs), Glutathione-S-Transferases (GSTs), UDP-Glycosyltransferases (UGTs), Carboxyl/Cholinesterases (CCEs) and ATP-Binding Cassette (ABC) transporters. Using this comparative approach we show that sand flies have evolved diverse CYP and GST gene repertoires, with notable lineage-specific expansions in gene groups evolutionarily related to known xenobiotic metabolizers. Furthermore, we show that sand flies have conserved orthologs of a) CYP4G genes involved in cuticular hydrocarbon biosynthesis, b) ABCB genes involved in xenobiotic toxicity and c) two primary insecticide targets, acetylcholinesterase-1 (Ace1) and Voltage Gated Sodium Channel (VGSC). The biological insights and genomic resources produced in this study provide a foundation for generating and testing hypotheses regarding the molecular mechanisms underlying sand fly adaptations to xenobiotics.

Species, Natural Leishmania spp. Detection and Blood Meal Sources of Phlebotomine Sandflies (Diptera: Psychodidae: Phlebotominae) in Peridomiciles from a Leishmaniases Endemic Area of Brazil

Leishmaniases are important neglected tropical diseases caused by protozoans of the genus Leishmania spp. The female sandflies bite (Diptera: Psychodidae: Phlebotominae) is the main transmission form in the epidemiological chains of these diseases. Thus, studies on Phlebotominae subfamily are fundamental to improve the comprehension of the leishmaniases epidemiology, revealing relationships of these dipterans with the parasite and reservoirs. An entomological survey of Phlebotomine sandflies was carried out to investigate the fauna, Leishmania spp. DNA detection and blood meals sources of female sandflies captured in peridomiciles areas from a leishmaniases endemic area of São Paulo state, Brazil. A total of 637 Phlebotomine sandflies specimens were captured, and twelve species identified, some of them proven or suspected vectors of tegumentary leishmaniasis (TL) and visceral leishmaniasis (VL). Evandromyia (Aldamyia) carmelinoi and Lutzomyia (Lutzomyia) longipalpis PCR positive to Leishmania (Leishmania) infantum kinetoplast minicircle DNA (kDNA) were identified. Also, Leishmania (Leishmania) amazonensis kDNA was found in Evandromyia (Aldamyia) lenti and Lu. (Lu.) longipalpis. Regarding blood meals source, DNA of swine, humans, dogs, cattle, chickens, and opossums were detected in the midgut of Phlebotomine sandflies females captured in the study area. Our results highlight ecological relationships among different species of Phlebotomine sandflies, domestic and wild-synanthropic vertebrates (including humans) and two Leishmania species in peridomiciles from a leishmaniases endemic area of Brazil.

Phlebotomine sand flies in rural Mayan communities of Southern Mexico: The heterogeneity of the ruralscape increases the entomological risk

In the Yucatan Peninsula, tropical preserved forests harbor a high diversity of phlebotomine sand fly species, potential vectors of Leishmania. As a result, a significant risk of contracting localized cutaneous leishmaniasis (LCL) is associated with entry into these forest ecosystems. However, with the current trajectory of land use in the region, communities now live within modified landscapes which could increase their risk of contact with vectors. In this study, we characterized the sand fly fauna and its relationship with the characteristics of peridomestic habitats in two rural communities in Yucatan characterized by contrasting records of leishmaniasis. Five human dwellings in each community were randomly selected and the peridomestic landscape was characterized (i.e., type and percentage of land use). For the collection of sand flies, CDC traps were deployed in both the intra and peridomicile. Differences in alpha and beta diversity between communities and ecotopes were estimated considering three separate groups, all species together, zoophilic species, and anthropophilic species. In total, 1, 241 sand flies represented by eight species were collected from November 2021-March 2022. Both communities registered the presence of sand flies in the intra and peridomicile, and females were more abundant than males. However, the greatest diversity of species was recorded in the peridomicile of the community with the highest composition of land uses. Our study demonstrates that the transformation of the forest around the communities favors the abundance and richness of sand flies in the peridomestic environment. We discuss the limitations and implications of our findings regarding the potential risk of the emergence of peri‑rural cycles of leishmaniasis in the region.

Phylogenetic relations among Mexican phlebotomine sand flies (Diptera: Psychodidae) and their divergence time estimation.

Phlebotomine sand flies (Diptera: Psychodidae: Phlebotominae) have biological relevance as vectors of several pathogens. To ensure periodic entomological monitoring it is necessary to have efficient and accurate tools for an adequate taxonomic identification. There are only few studies on phylogenetic analyses of phlebotomine sand flies from Neotropics, based mostly on morphological and/or molecular data, which makes the delimitation of intra- and interspecific variability of species challenging. Here we generated new molecular information on sand fly species distributed in endemic areas of leishmaniasis in Mexico, using mitochondrial and ribosomal genes, and incorporating morphological information available. Specifically, we established their phylogenetic relationships, and estimated their divergence time. Our study provides molecular information for 15 phlebotomine sand fly species from different areas of Mexico, contributing to the genetic inventory and phylogenetic relations among Neotropical species of the subfamily Phlebotominae. Mitochondrial genes proved to be suitable markers for the molecular identification of phlebotomine sand flies. However, the incorporation of additional nuclear gene information could increase the significance of phylogenetic inferences. We also provided evidence about a possible divergence time of phlebotomine sand fly species, supporting their presumable origin in the Cretaceous period.

First evidence of experimental genetic hybridization between cutaneous and visceral strains of Leishmania donovani within its natural vector Phlebotomus argentipes

Leishmaniasis is a neglected tropical disease caused by protozoan parasites of genus Leishmania, and transmitted by different species of Phlebotomine sand flies. More than 20 species of Leishmania are known to cause disease in humans and other animals. Leishmania donovani species complex is known to have a vast diversity of clinical manifestations in humans, but underlying mechanisms for such diversity are yet unknown. Long believed to be strictly asexual, Leishmania have been shown to undergo a cryptic sexual cycle inside its sandfly vector. Natural populations of hybrid parasites have been associated with the rise of atypical clinical outcomes in the Indian subcontinent (ISC). However, formal demonstration of genetic crossing in the major endemic sandfly species in the ISC remain unexplored. Here, we investigated the ability of two distinct variants of L. donovani associated with strikingly different forms of the disease to undergo genetic exchange inside its natural vector, Phlebotomus argentipes. Clinical isolates of L. donovani either from a Sri Lankan cutaneous leishmaniasis (CL) patient or an Indian visceral leishmaniasis (VL) patient were genetically engineered to express different fluorescent proteins and drug-resistance markers and subsequently used as parental strains in experimental sandfly co-infection. After 8 days of infection, sand flies were dissected and midgut promastigotes were transferred into double drug-selective media. Two double drug-resistant, dual fluorescent hybrid cell lines were recovered, which after cloning and whole genome sequencing, were shown to be full genomic hybrids. This study provides the first evidence of L. donovani hybridization within its natural vector Ph. argentipes.

Description of a new species of the genus Lutzomyia França, 1924 (Diptera: Phlebotominae) and of the male of Lutzomyia fonsecai (Costa Lima, 1932).

Lutzomyia itambe sp. n. is described as a new species of neotropical cavernicolous phlebotomine sand fly based on specimens of males and females collected in the Gruta do Itambé, Altinópolis municipality, São Paulo State. In addition to this, we describe the male of Lutzomyia fonsecai (Costa Lima, 1932) collected near their type-locality in Bolivia. These descriptions are supported by illustrations that detail the morphological and morphometrical characteristics of the specimens. Lutzomyia itambe sp. n., L. fonsecai, along with L. dispar Martins & Silva, 1963, comprise the already named "Fonsecai complex". Both sex present parallel labial sutures, not forked, and males can be differentiated by parameral characters, while in females the distinction is made by characters of the palpi and spermathecae.

Identification of phlebotomine sand fly (Diptera: Psychodidae) in Atlantic forest fragments and their dispersal to urban area.

The geographical distribution of sand flies in Brazil has been the subject of some studies, yet there is no information about the phlebotomine fauna in João Pessoa, State of Paraíba, Brazil. The aim of this work is to evaluate the occurrence and distribution of sand flies in the Atlantic forest fragments and to evaluate a possible dispersion in 06 nearby districts. Light traps were used during three consecutive nights, supplemented by an aspirator during the dry period and rainy season. A total of 222 sand flies were found, 143 (130 males and 13 females) in the Atlantic forest, and 79 in urban areas. During the entire dry season, three species of phlebotomine sand flies were recorded in 11 forest fragments, Lutzomyia longipalpis, Lu. migonei and Lu. whitmani. During the rainy season, only Lu. longipalpis was found. This was the only species identified in the studied neighborhoods during both seasons. The differences in diversity of sand flies encountered between natural habitats and urban areas may thus be correlated mostly with adaptations to particular habitats and availability of food. One species (Lu. longipalpis) appears to be rapidly adapting to urban areas because of deforestation.

Faunal richness and checklist of sandflies (Diptera: Psychodidae) in India

This review aims to fill the voids and to update the checklist of sandfly fauna along with its spatial distribution in India. Resource databases i.e. either online or offline were searched to deduce the information to systematize the Indian sandfly fauna. Articles/data retrieved were screened and analysed to further update the available latest checklist. The species name and authorship were given in accord with the International Code for Zoological Nomenclature. We compiled an updated checklist of reported Indian sandfly species along with their state-wise distribution till 2022 as per published literature. Kerala has maximum number of species reports when compared to other endemic states and states with pockets of transmission. Phlebotomus argentipes is the most widely distributed, recorded so far, followed by other Sergentomiya and Phlebotomus species in India. In this review, we have also described the vector and non-vector species of sandfly prevalent in different parts of the country. Phlebotoiella eoindianensis, an amber fossil sandfly species recorded from Gujarat might be older than other records of Indian sandfly fauna. So far 69 species (4 genera and 15 subgenera/groups) of Phlebotomine sandflies have been recorded in India. Proper knowledge of species diversity and its distribution is a prerequisite for planning a systematic vector control strategy and disease management.

Epidemiological Features of Cutaneous Leishmaniasis in Hilly and Plot Areas of Tribal Districts, Khyber-Pakhtunkhwa Province Pakistan

Cutaneous Leishmaniasis is caused by flagellated parasitic protozoans of the genus Leishmania and is spread by vectors. This is a new threat that is endemic to the tropics and subtropics and has a broad geographic distribution. The current research was carried out in all tribal districts of Khyber Pakhtunkhwa province to 2020. The prevalence of Cutaneous Leishmaniasis was found to be higher in children aged 5 to 10 years old in the current research, due to a weakened immune system. In the province, 23 species of phlebotomine sand-flies belonging to the genera Phlebotomus Sergentomyia and grassomiya were discovered. Cutaneous Leishmaniasis is caused by flagellated parasitic protozoans of the genus Leishmania, which are transmitted via the bite of a mosquito. This is an emergent threat and endemic in areas of tropic and sub-tropics and has the epidemiological aspects of Cutaneous Leishmaniasis during the recent epidemic in tribal districts of Khyber Pakhtunkhwa in 2020. The suspected patients of Leishmaniasis from different areas of tribal districts were examined. We came across 700 cases during 3-month period from may to july2020. A major portion G2 ([41.1%; n = 290) of these patients were in age 6 to–10 years. The infection rate was higher in male (75.3%; n = 525) compared to females (25%;n = 125). Both gender and age showed a significant effect on the occurrence of infection. The current study report CL outbreak in the tribal districts of Khyber Pakhtunkhwa which need immediate response from the healthcare authorities. In addition, extensive awareness campaigns are needed for timely prevention of such outbreak. Keywords: Cutaneous Leishmaniasis, outbreak

Entomological Survey of Sandflies Vector (Diptera: Psychodidae: Phlebotominae) in Asser Region, Saudi Arabia

Phlebotomine sandflies (Diptera: Psychodidae) are the natural vectors of Leishmaniasis. This study aimed to identify the distribution and classification of phlebotomine sandflies vector in the Aseer region, Saudi Arabia. Twice entomological surveys were carried out in four geographical locations (Abha, Rijal Alma, Muhayil, and Asahel) within the Aseer Region during the period from November to December 2020. Phlebotomine sandflies were collected using light traps (10 traps/ month). Identification of species was done under a binocular microscope at 40x. Female and male specimens were identified by observing head and genital structures under the microscope using the morphological keys. Six species of phlebotomine sandflies with 107 were collected throughout the study period (November and December 2020). P.bergeroti species is the most abundant (54.2%) followed by P. alexandri (18.6%) and P.orientalis (12.1%) of the total flies collected ,while P.papatasi, P.sergenti, and P.arabicus were identified less abundance in Aseer region of the total flies collected . More phlebotomine sandfly species were found in the Abha province (38.3%) followed by Rijal Alma province (31.7%) while the least abundant collected in the Muhayil province (8.4%) this study showed that P.bergeroti and P.alexandri are widespread in the Aseer region, specifically in Abha and the Rijal Alma provinces. More studies are needed to understand the preference, behavior and vectorial efficiency of sandfly vectors in Asser region.

Effects of Migonemyia migonei salivary gland homogenates on Leishmania (Viannia) braziliensis infection in BALB/c mice

Cutaneous leishmaniasis caused by Leishmania (Viannia) braziliensis is the most widespread clinical form of leishmaniasis in the Americas. Migonemyia migonei is a widely distributed phlebotomine sand fly species in Brazil and has been implicated as a vector for L. (V.) braziliensis. In the present study, we investigated the effects of salivary gland homogenates (SGH) of Mg. migonei on the course of L. (V.) braziliensis infection in BALB/c mice. Mice were separated into four groups (six mice per group): CTRL (uninfected mice); SGH (mice inoculated with Mg. migonei SGH); SGH+LEISH (mice inoculated with Mg. migonei SGH plus L. (V.) braziliensis promastigotes); LEISH (mice inoculated with L. (V.) braziliensis promastigotes). Mice were followed up for 8 weeks and the cellular immune response was evaluated by flow cytometry at the end of the experiment. Analysis of cytokine production by splenic cells stimulated with 0.5 SGH, 0.25 SGH of Mg. migonei or L. (V.) braziliensis soluble antigen stimulation (LSA) demonstrated that upon stimulation with SGH 0.25, the production of IL-17A and TNF was not sustained in the SGH group, with decreasing levels of these cytokines after 5 days compared to 3 days of incubation. Analyzing the production of cytokines after LSA stimulation, we observed lower levels of IL-17A in the SGH group after 5 days compared to 3 days. The same was observed for IFN-γ in the SGH group. Yet, the levels of TNF were significantly higher in the LEISH group after 5 days compared to 3 days. Among SGH+LEISH and LEISH mice, three animals in each group developed skin lesions on the tail, the mean lesion size was significantly higher in the LEISH group. Our study suggests that Mg. migonei SGH may modulate BALB/c immune response, as reflected by the low production or early decrease of pro-inflammatory cytokines in splenic cell cultures following stimulation with L. (V.) braziliensis antigen. Our data also suggest that Mg. migonei saliva may reduce the lesion size in BALB/c mice, but further research with a larger sample size is needed to confirm this hypothesis.

The Psychodidae (Diptera) of Ja National Park (Amazonas, Brazil) with description of two new species of Psychodinae.

The Ja National Park, located in the Amazon, is the largest National Park of Brazil and still its insect fauna is barely known. Herein we describe two new species of Psychodinae, Alepia iy sp. nov. and Parasetomima timmirima sp. nov., and report 19 other species of Psychodidae, subfamilies Phlebotominae, Psychodinae and Trichomyiinae collected from this Conservation Unit. Micrommatos Quate Brown, represented by M. stephaniae Quate Brown, and Platyplastinx culmosus Quate Brown are recorded for the first time for Brazil. Among the collected phlebotomine sand fly species, three species have previously been implicated in transmission of Leishmania: Nyssomyia anduzei (Rozeboom), Psychodopygus ayrozai (Barretto Coutinho) and Trichophoromyia ubiquitalis (Mangabeira).

Description of Evandromyia cristacapita sp. nov., a new sand fly species of the Argentinian Chaco

A new species of phlebotomine sand fly collected in the rural and peri-urban areas of wet and dry subregions of the Chaco Province, Argentina, is described. Illustrations of male and female adults are presented. Morphological characters allow the inclusion of the new species within the Evandromyia genus, Barrettomyia subgenus, Cortelezzii series (Diptera: Psychodidae). Furthermore, we present an identification key for the Cortelezzii series of the Barrettomyia subgenus with a new distinct species complex for its correct identification. The species was denominated as Evandromyia cristacapita sp. nov.

Genetic structure of allopatric populations of Lutzomyia longipalpis sensu lato in Brazil

Lutzomyia longipalpis sensu lato is a complex of phlebotomine sand fly species, which are widespread in the Neotropics. They have a great medico-veterinary importance due their role as vectors of Leishmania infantum, the causative agent of visceral leishmaniasis. Morphological variations of Lu. longipalpis s.l. males were reported in the late 1960s in Brazil. Male populations can present either one pair of spots on third abdominal tergites or two pairs on third and fourth ones, namely 1S and 2S phenotypes, respectively. Since then, there has been much interest on the taxonomic status of Lu. longipalpis s.l. Thereafter, several lines of evidence have been congruent in suggesting the existence of an uncertain number of cryptic species within Lu. longipalpis s.l. in Brazil. Herein, a 525 bp-fragment of the period gene was used for assessing the genetic structure and phylogenetic relationship of Lu. longipalpis s.l. populations in Brazil. We performed two set of analyses, first we originally sequenced three populations (Passira, Santarém and Teresina) of Lu. longipalpis s.l. and compared them. Thereafter, we performed a global analysis including in our dataset other three pairs of sympatric populations of Lu. longipalpis s.l. from three Brazilian localities available in GenBank. Fixed single nucleotide polymorphisms (SNPs) sharing, maximum likelihood inference, genetic structure and haplotype analyses revealed the presence of two genetic groups, one composed of Teresina population, and the other encompassing Passira and Santarém populations. The global analysis reflected the first of its kind, and two prominent groups were observed: the clade I comprising Teresina 1S, Bodocó 1S, Caririaçu 1S and Sobral 1S; and the clade II encompassing Passira 2S, Santarém 1S, Bodocó 2S, Caririaçu 2S and Sobral 2S. Genetic differentiation data suggested a limited gene flow between populations of the clade I versus clade II. Our results disclosed the presence of two prominent genetic groups, which could reasonably represent populations of Lu. longipalpis s.l. whose males produce the same courtship song.

Prevalence of Leishmania infection in three communities of Oti Region, Ghana.

BackgroundLeishmaniasis is a neglected tropical disease caused by parasites of the genus Leishmania and is transmitted by various species of female phlebotomine sand flies. The first report of cutaneous leishmaniasis (CL) in Ghana refer to a cluster of cases in 1999–2003 in the Ho municipality of the Volta Region. We conducted an epidemiological assessment in the Oti Region, encouraged by recent reports of potential cases of CL.Methodology/Principal findingsUsing a cross-sectional study design, the exposure to Leishmania was investigated in three communities of the Oti Region based on the leishmanin skin test (LST). LST results for 3,071 participants comprising 1091, 848, and 1132 persons from the communities of Ashiabre, Keri, and Sibi Hilltop, indicated an overall prevalence of exposure to Leishmania infection of 41.8% and individual community prevalence of 39.4%, 55.1%, and 34.2% respectively. Being male [AOR = 1.27; CI: 1.09, 1.49], and living in Keri [AOR = 1.83; CI: 1.43, 2.34] were associated with an increase in the odds of exposure to Leishmania. Being 5–10 years old [AOR = 1.48; CI: 1.06, 2.05], 11–17 years old [AOR = 2.03; CI: 1.45, 2.85], 18–40 years old [AORR = 2.83; CI: 1.81, 4.43] and 41–65 years old [AOR = 5.08; CI: 2.98, 8.68] were also significantly associated with increased odds of being exposed to Leishmania.Conclusions/SignificanceThis study demonstrated exposure to Leishmania in the study communities and also identified associated factors. Future efforts aimed at reducing exposure to Leishmania infection in the study area should take the associated factors into consideration.

Investigation of natural infection of Phlebotomine (Diptera: Psychodidae) by Leishmania in Tunisian endemic regions

Leishmaniases are caused by protozoan parasites of the genus Leishmania transmitted by females blood-feeding phlebotomine insects (Diptera: Psychodidae). In Tunisia, cutaneous and visceral leishmaniases are of public health concern. In Tunisia, 17 species of phlebotomine sand flies are described. Here we investigate natural infection in Tunisian mixed foci regions of leishmaniases. We trap female sandflies during the Leishmania transmission season in the country's central-eastern and northern parts. We investigate Leishmania infection using PCR-RFLP targeting the ITS1 ribosomal DNA, followed by enzymatic digestion with HaeIII; then, we identify sand flies using molecular methodologies. We confirm the presence of Phlebotomus papatasi and Phlebotomus perniciosus infected by L. major and L. infantum parasites in Tunisia.

First molecular evidence of frogs as a food source for sand flies (Diptera: Phlebotominae) in Brazilian caves.

Genus and species of phlebotomine sand flies have been recorded and described in caves in Brazil, but no study has provided the food source used by sand flies in these environments. Herein, we identified the blood source used by sand fly species in caves located at "Quadrilátero Ferrífero" (QF), Minas Gerais state. Specimens were manually collected near or on anurans inside ferruginous caves in Serra do Gandarela National Park and Serra do Rola Moça State Park. Males and females were placed in vials with 70% alcohol and stored at -10°C. Females engorged, after specific identification, had DNA extracted and followed for PCR amplification using specific primers. Sequencing was analyzed in the GenBank and Barcode of Life. A total of 198 specimens were collected (107 females and 91 males), all of them belonging to species Sciopemyia aff. microps (88.89%), Sciopemyia sordellii (10.61%), or Martinsmyia oliveirai (0.50%). When it comes to the females, 89 were S. aff. microps and 18 S. sordellii. Nineteen engorged females of S. aff. microps were analyzed and most of them (n=18) presented blood from Bokermannohyla martinsi and one contained blood from Scinax fuscovarius. The blood present in engorged females of S. sordellii (n=4) was from B. martinsi. Sciopemyia genus specimens are commonly found in collections carried out inside natural caves, but this was the first study to prove that females of this genus feed on cold-blooded animals in nature. HIGHLIGHTS: • Here we proved that sand flies feed in cold-blooded animals in in Brazilian caves. • Females of the Sciopemyia genus were for the first time found feeding in natural habitats. • Anurans of the family Hylidae were identified as source by molecular analyzes. • Insect bloodmeal identification can help assessing the fauna in several biomes. • This is the first record of S. aff. micropsin caves of Brazil.

The impacts of the Messinian Salinity Crisis on the biogeography of three Mediterranean sandfly (Diptera: Psychodidae) species

The desiccation of the Mediterranean Basin at the end of the Miocene was a milestone in the evolution of the Mediterranean sandfly fauna. This severe environmental change should have notably influenced their paleobiogeography as well as paleoecology and might have triggered the rapid speciation of the ancestors of the extant European sandfly species. The aim of this study was to explore how the Messinian Salinity Crisis could influence the distribution and migration routes of the ancient Mediterranean sandfly species. The unknown ecological requirements of this ancient species were replaced by the distribution-limiting climatic values of three species of extant European phlebotomine sandflies which represent the three ecological types of European sandfly fauna. The former potential occurrence patterns were determined by Climate Envelope Modelling Method. As a climate model for the Messinian Period in the Mediterranean Basin, the modified mid-Pliocene warm period model was used. The thermal surplus of the desiccated seafloor was reconstructed based on the atmospheric lapse rate. It was found that the extraordinary hot climate of the Mediterranean abyssal plain did not allow the direct cross-migration of the ancient sandfly species anywhere between Europe and North Africa neither through Gibraltar nor the Strait of Sicily. While Phlebotomus neglectus and Phlebotomus papatasi could colonize the Adriatic Plain, Phlebotomus ariasi could not. The results indicate that the Messinian played an important role in the speciation rather than migration of the ancestors of present-day Mediterranean sandflies.

Occurrence of Phlebotomine sand flies (Diptera: Psychodidae) in the northeastern plain of Italy

BackgroundRecent climate and environmental changes have resulted in the geographical expansion of Mediterranean Leishmania infantum vectors towards northern latitudes and higher altitudes in different European countries, including Italy, where new foci of canine leishmaniasis have been observed in the northern part of the country. Northern Italy is also an endemic area for mosquito-borne diseases. During entomological surveillance for West Nile virus, mosquitoes and other hematophagous insects were collected, including Phlebotomine sand flies. In this study, we report the results of Phlebotomine sand fly identification during the entomological surveillance conducted from 2017 to 2019.MethodsThe northeastern plain of Italy was divided by a grid with a length of 15 km, and a CO2-CDC trap was placed in each geographical unit. The traps were placed ~ 15 km apart. For each sampling site, geographical coordinates were recorded. The traps were operated every two weeks, from May to November. Sand flies collected by CO2-CDC traps were identified by morphological and molecular analysis.ResultsFrom 2017 to 2019, a total of 303 sand flies belonging to the species Phlebotomus perniciosus (n = 273), Sergentomyia minuta (n = 5), P. mascittii (n = 2) and P. perfiliewi (n = 2) were collected, along with 21 unidentified specimens. The trend for P. perniciosus collected during the entomological surveillance showed two peaks, one in July and a smaller one in September. Sand flies were collected at different altitudes, from −2 m above sea level (a.s.l.) to 145 m a.s.l. No correlation was observed between altitude and sand fly abundance.ConclusionsFour Phlebotomine sand fly species are reported for the first time from the northeastern plain of Italy. Except for S. minuta, the sand fly species are competent vectors of Leishmania parasites and other arboviruses in the Mediterranean Basin. These findings demonstrate the ability of sand flies to colonize new environments previously considered unsuitable for these insects. Even though the density of the Phlebotomine sand fly population in the plain areas is consistently lower than that observed in hilly and low mountainous areas, the presence of these vectors could herald the onset of epidemic outbreaks of leishmaniasis and other arthropod-borne diseases in areas previously considered non-endemic.Graphical

Diversity, Co-Occurrence, and Nestedness Patterns of Sand Fly Species (Diptera: Psychodidae) in Two Rural Areas of Western Panamá.

Simple SummarySand flies are insects that can transmit the parasites causing leishmaniasis, a major neglected tropical disease. In the Americas, these insects are highly diverse, and unlike what is observed for other vector-borne diseases, many species co-occur in sites where this disease affects human populations. Here, we present results from a two-year-long study where we study how the number of species changes in two rural areas of Western Panamá with different land use cover and through the dry and wet seasons. We found that species number increased during the wet season and in plots with higher natural forest cover and that species number decreased in both areas in plots when the forest cover decreased, with some species changing through the seasons, and some species disappearing when comparing the sand fly faunas of the most forested with less forested plots. However, our results suggest that seasonality, or the change from a dry to rainy season, can be a more important driver of the number of species locally observed in the studied areas.Cutaneous Leishmaniasis transmission in the New World is observed in areas with rich sand fly species’ faunas. The diversity and composition of sand fly species can change in response to seasonal weather and land use changes. Here, we present results from a two-year-long study where we collected, using Centers for Disease Control (CDC) light traps, sand flies from two rural areas, Las Pavas (LP) and Trinidad de las Minas (T) in western Panamá. Over 710 trap-nights, we collected 16,156 sand flies from 15 genera and 35 species. We identified 34 species in T, and the most abundant species collected was Nyssomyia trapidoi (Fairchild and Hertig, 1952) (n = 2278, 37%), followed by Psychodopygus panamensis (Shannon, 1926) (n = 1112, 18%), and Trichopygomyia triramula (Fairchild and Hertig, 1952) (n = 1063, 17%). In LP, we identified 26 species, and the most abundant species collected were Ty. triramula (n = 4729, 48%), and Ps. panamensis (n = 3444, 35%). We estimated a higher species’ richness in T (Chao2 ± S.E.: 36.58 ± 3.84) than in LP (27.49 ± 2.28). In T, species’ richness was significantly higher in the rainy season, but no seasonal differences were observed in LP. Species’ assemblages were nested in the two areas. Phlebotomine sand fly species’ abundance increased at the two sites during the rainy season. Our data suggest that seasonality is more important than land use as a factor driving sand fly species’ diversity at the studied sites.