The sandfly fauna (Diptera: Psychodidae: Phlebotominae) of the Parque Estadual da Serra da Tiririca,Rio de Janeiro, Brazil

Cutaneous leishmaniasis (CL) in the state of Rio de Janeiro is sporadic and canbe characterised as a peridomestic transmission that occurs in modified naturalenvironments. The aim of this work was to study the fauna and ecologicalcharacteristics of sandflies in an environmentally protected area (the StatePark of Serra da Tiririca) within the remnants of the Atlantic Forest in themunicipalities of Niterói and Maricá and their possible relationship withleishmaniasis. Captures were performed using light traps during the night once amonth for one year in both sylvatic environments and areas surrounding homesnear the park. A total of 1,037 sandflies were captured, belonging to ninegenera and 12 species: Evandromyia tupynambai (34.1%),Migonemyia migonei (20.6%), Brumptomyiacunhai (13.8%), Micropygomyia schreiberi (9.7%),Psathyromyia lanei (6.5%), Brumptomyianitzulescui (5.7%), Evandromyia edwardsi(5.4%), Nyssomyia intermedia (2.8%), Evandromyiacortelezzii (0.6%), Pintomyia bianchigalatiae(0.5%), Lutzomyia longipalpis (0.2%) and Sciopemyiamicrops (0.1%). Both Mg. migonei and Ny.intermedia may be acting as vectors of CL in this area.     

Assessing the importance of four sandfly species (Diptera: Psychodidae) as vectors of Leishmania mexicana in Campeche,Mexico

Localized cutaneous leishmaniasis represents a public health problem in many areas of Mexico, especially in the Yucatan Peninsula. An understanding of vector ecology and bionomics is of great importance in evaluations of the transmission dynamics of Leishmania parasites. A field study was conducted in the county of Calakmul, state of Campeche, during the period from November 2006 to March 2007. Phlebotomine sandfly vectors were sampled using Centers for Disease Control light traps, baited Disney traps and Shannon traps. A total of 3374 specimens were captured in the two villages of Once de Mayo (93.8%) and Arroyo Negro (6.1%). In Once de Mayo, the most abundant species were Psathyromyia shannoni, Lutzomyia cruciata, Bichromomyia olmeca olmeca and Psychodopygus panamensis (all: Diptera: Psychodidae). The Shannon trap was by far the most efficient method of collection. The infection rate, as determined by Leishmania mexicana‐specific polymerase chain reaction, was 0.3% in Once de Mayo and infected sandflies included Psy. panamensis, B. o. olmeca and Psa. shannoni. There were significant differences in human biting rates across sandfly species and month of sampling. Ecological niche modelling analyses showed an overall overlap of 39.1% for the four species in the whole state of Campeche. In addition, the finding of nine vector–reservoir pairs indicates a potential interaction. The roles of the various sandfly vectors in Calakmul are discussed.     

Predicting the geographic distribution of Lutzomyia longipalpis (Diptera: Psychodidae) and visceral leishmaniasis in the state of Mato Grosso do Sul,Brazil

To understand the geographic distribution of visceral leishmaniasis (VL) in the state of Mato Grosso do Sul (MS), Brazil, both the climatic niches of Lutzomyia longipalpis and VL cases were analysed. Distributional data were obtained from 55 of the 79 counties of MS between 2003-2012. Ecological niche models (ENM) of Lu. longipalpis and VL cases were produced using the maximum entropy algorithm based on eight climatic variables. Lu. longipalpis showed a wide distribution in MS. The highest climatic suitability for Lu. longipalpis was observed in southern MS. Temperature seasonality and annual mean precipitation were the variables that most influenced these models. Two areas of high climatic suitability for the occurrence of VL cases were predicted: one near Aquidauana and another encompassing several municipalities in the southeast region of MS. As expected, a large overlap between the models for Lu. longipalpis and VL cases was detected. Northern and northwestern areas of MS were suitable for the occurrence of cases, but did not show high climatic suitability for Lu. longipalpis . ENM of vectors and human cases provided a greater understanding of the geographic distribution of VL in MS, which can be applied to the development of future surveillance strategies.     

Host preferences of the phlebotomine sandfly Lutzomyia longipalpis in Amazonian Brazil

Experiments were undertaken to determine the relative attractiveness of humans, dogs and chickens to Lutzomyia longipalpis, the principal vector of Leishmania chagasi causing American visceral leishmaniasis. Field experiments in two villages on Marajó Island, Pará State, Brazil, showed that one boy attracted significantly more flies than one dog or chicken, and slightly fewer flies than a group of six chickens. Experiments with laboratory-bred female flies showed that a significantly greater number of flies engorged on a single human than on either a single dog or chicken, and man-biting catches demonstrated the willingness of flies to bite in the field. It appears that Lu.longipalpis has catholic feeding habits, the attractiveness of different hosts being largely a function of their relative sizes. These results are discussed with reference to the epidemiology of visceral leishmaniasis in Brazil.     

Sugar feeding and fluid destination control in the phlebotomine sandfly Lutzomyia longipalpis (Diptera: Psychodidae)

Sandfly feeding behaviour and destination of coloured sugar meals in the gut of Lutzomyia longipalpis were investigated with particular attention to the role of the crop. Sandflies were able to ingest sugar from liquid drops, microcapillaries, a slice of pear and even sugar powder. In most cases the flies adopted a 'sugar feeding mode' with raised palps. As the fruit dried, flies of both sexes fed by piercing the tissue with the proboscis. All sugar-fed flies had a full crop plus a small amount of sugary fluid in the thoracic mid-gut, i.e. past the stomodaeal valve. Dissections of flies interrupted during feeding showed that the very first trace of sugar passed through the stomodaeal valve, but that the rest of the meal was diverted into the crop. This suggests that closure of the stomodaeal valve is initiated only after a small volume of sugar solution has passed through it.     

Incorporating biotic interactions in the distribution models of African wild silk moths (Gonometa species,Lasiocampidae) using different representations of modelled host tree distributions

Biotic interactions influence species niches and may thus shape distributions. Nevertheless, species distribution modelling has traditionally relied exclusively on environmental factors to predict species distributions, while biotic interactions have only seldom been incorporated into models. This study tested the ability of incorporating biotic interactions, in the form of host plant distributions, to increase model performance for two host‐dependent lepidopterans of economic interest, namely the African silk moth species, Gonometa postica and Gonometa rufobrunnea (Lasiocampidae). Both species are dependent on a small number of host tree species for the completion of their life cycle. We thus expected the host plant distribution to be an important predictor of Gonometa distributions. Model performance of a species distribution model trained only on abiotic predictors was compared to four species distribution models that additionally incorporated biotic interactions in the form of four different representations of host plant distributions as predictors. We found that incorporating the moth–host plant interactions improved G. rufobrunnea model performance for all representations of host plant distribution, while for G. postica model performance only improved for one representation of host plant distribution. The best performing representation of host plant distribution differed for the two Gonometa species. While these results suggest that incorporating biotic interactions into species distribution models can improve model performance, there is inconsistency in which representation of the host tree distribution best improves predictions. Therefore, the ability of biotic interactions to improve species distribution models may be context‐specific, even for species which have obligatory interactions with other organisms.     

Diversity and distribution of sandflies (Diptera: Psychodidae: Phlebotominae) in a military area in the state of Amazonas, Brazil

This study reports the distribution, ecotopes and fauna diversity ofsandflies captured in five training bases on a military reserve in Manaus, stateof Amazonas (AM). A total of 10,762 specimens were collected, which weredistributed among 58 species, with the highest number recorded at BaseInstruction 1 (BI1). A higher rate of species richness was found at the BaseInstruction Boina Rajada and low levels of diversity associated with a highabundance index with the clear dominance of Lutzomyiaumbratilis, Lutzomyia ruii and Lutzomyiaanduzei were found at BI1. The abundance of Lu.umbratilis raises the possibility of outbreaks of Americancutaneous leishmaniasis by the main vector of the disease in AM.     

Sugar meal sources for the phlebotomine sandfly Lutzomyia longipalpis in Ceará State, Brazil

Abstract. In the Brazilian village of BoqueiraTo do Renato Parente, Ceará State, where visceral leishmaniasis is endemic, significant variation in the abundance of phlebotomine sandflies between different types of vegetation was demonstrated by castor oil sticky trap collections. Population densities of Lutzomyia longipalpis (Lutz & Neiva) sandflies were higher in beans and maize crops than in the surrounding open and tree scrub. Significant relationships were detected between the abundances of sandflies and aphids, suggesting aphid honey dew as a potential food source. Sugar meal analysis, using high-performance anion exchange (HPAE) chromatography with pulsed amperometric detection (PAD) and the cold anthrone test, was used to demonstrate that significantly more sandflies fed on bean plants contaminated with aphids and honeydew than on uncontaminated beans. Furthermore, higher concentrations of sugars were detected in flies which fed on aphid/honeydew-contaminated beans, suggesting that sugar was more easily available and/or that honeydew/aphids act as phagostimulants for sandflies. Amongst wild sandflies collected from a bean field, significantly more female sandflies were 'sugar-positive' than males, though the sugar concentrations in positive sandflies were similar for both sexes. The concentrations of di- and trisaccharides in sandfly homogenates, honeydew extracts and phloem exudates were very low.     

Potential distributions of phlebotomine sandfly vectors of human visceral leishmaniasis caused by Leishmania infantum in Morocco

Zoonotic visceral leishmaniasis is a common vector-borne systemic disease caused by Leishmania infantum (Kinetoplastida: Trypanosomatidae). In Morocco the situation is complex: many sandfly species have been collected in areas in which the disease is endemic, but only Phlebotomus ariasi, Phlebotomus perniciosus and Phlebotomus longicuspis (Diptera: Psychodidae) have been confirmed to have vectorial roles. The objective of the present study was to ascertain the potential distribution of L. infantum and its vectors in Morocco, using ecological niche modelling. Vector records were obtained from field collections of the Laboratory team and from previously published entomological observations. Epidemiological data for L. infantum modelling were obtained from Moroccan Ministry of Health reports. The jackknife test indicated that the bioclimatic variables with the greatest influence on model development for all species were annual precipitation and precipitation in the driest quarter of the year. MaxEnt model representations for sandfly species that act as vectors of L. infantum showed the widespread geographic distribution of these species in Morocco, specifically in northern and central Morocco, where foci of visceral leishmaniasis are found. The ecological niche modelling points out areas in which the probability of occurrence of these species is higher. This information should be considered as a starting point for further research to fully elucidate the ecology and epidemiology of these species, as well as of the pathogens they transmit.     

Richness and diversity of sand flies (Diptera,Psychodidae) in an Atlantic rainforest reserve in southeastern Brazil

Our objective was to study and evaluate the richness and diversity of Phlebotominae fauna in the Duas Bocas Biological Reserve (DBBR) in the state of Espírito Santo, in southeastern Brazil. Sand fly collections were carried out during four consecutive nights each month between August 2007 and July 2008 at DBBR by using CDC automatic light traps and an illuminated Shannon trap. Specific richness (S) and Shannon diversity index (H) was calculated for each trap. We collected 18,868 sand flies belonging to 29 species and 13 genera. Nyssomyia yuilli yuilli was the most abundant species followed by Psychodopygus ayrozai, Ps. hirsutus, Psathyromyia pascalei, and Ps. matosi. We recorded Brumptomyia cardosoi, Br. troglodytes, and Ps. geniculatus for the first time in the state of Espírito Santo. We discuss the differences in diversity and richness of the sand flies in both traps and in relation to other Brazilian localities and biomes. We also discuss the possibility of wild transmission of Leishmania in the DBBR and the influence of the sand fly species in leishmaniasis transmission to the adjacent areas of the reserve.     

The sandfly fauna,anthropophily and the seasonal activities of Pintomyia spinicrassa (Diptera: Psychodidae: Phlebotominae) in a focus of cutaneous leishmaniasis in northeastern Colombia

This study was conducted to identify the sandfly fauna and the anthropophilic species in a coffee-growing area of Villanueva, Norte de Santander, Colombia, a focus of American cutaneous leishmaniasis, and to analyse the relationship between the most frequent species and rainfall, relative humidity and temperature, with the aim of contributing to epidemiological surveillance in the area. Sandfly collections were performed fortnightly between February 2006-September 2007 using automatic light traps, Shannon traps, protected human bait and aspiration in resting places. A total of 7,051 sandflies belonging to 12 species were captured. Pintomyia spinicrassa (95.7%) predominated. Pintomyia oresbia and Lutzomyia sp. of Pichinde were found in the state of Norte de Santander for the first time. Pi. spinicrassa, Pintomyia nuneztovari, Micropygomyia venezuelensis, Lutzomyia (Helcocyrtomyia) scorzai and Lu. (Helcocyrtomyia) sp. were captured on the protected human bait. A significant association between Pi. spinicrassa abundance and the total rainfall and the average temperature and humidity 10 days before the collection was observed. The dominance of Pi. spinicrassa, a recognised vector of Leishmania braziliensis, especially during the dry periods, indicates that the risk of parasite transmission may increase.     

Correlates of the peridomestic abundance of Lutzomyia longipalpis (Diptera: Psychodidae) in Amazonian Brazil

Abstract. Abundance of the sandfly Lutzomyia longipalpis , the vector of Leishmania chagasi , was surveyed using CDC light-suction traps in fifteen villages and 180 homesteads on Marajo island, Para State, Brazil. Flies were most abundant in cultivated areas, secondary growth and open woodland, away from savanna grassland and forest. Within homesteads, the abundance of flies in animal sheds was weakly associated with the number of hosts kept therein, and inversely related to the number elsewhere, both human and animal. Houses harboured more flies if dogs were present and if the house had: a roof of thatch rather than of tiles or tin; a thatched roof which had not been treated with insecticide; relatively more holes in walls and roof. The sex ratio of flies was more male-biased at higher densities. We weigh the importance of these variables as risk factors for Le.chagasi infection.     

Identification of oviposition attractants for the sandfly Lutzomyia longipalpis (Diptera: Psychodidae) in volatiles of faeces from vertebrates

Abstract. Extracts of volatiles from rabbit and chicken faeces preferentially attracted gravid sandflies, Lutzomyia longipalpis (Lutz and Neiva), in an oviposition bioassay. In electrophysiology experiments, the same extracts selectively stimulated two olfactory cells while inhibiting another in ascoid sensilla on the antennae of these flies. Analysis of faeces volatiles by gas chromatography linked to ascoid sensillum recording revealed two early eluting electrophysiologically active components of rabbit faeces. These active compounds were identified in both rabbit and chicken faeces volatile extracts by gas chromatography -mass spectrometry as hexanal and 2-methyl-2-butanol. Hexanal stimulated one cell type and inhibited another, whereas 2-methyl-2-butanol stimulated a third cell type. A 1:l mixture of synthetic hexanal and 2-methyl-2-butanol elicited the same targeted oviposition response from gravid females on the treatment septum of the bioassay as did the total volatile extract of rabbit or chicken faeces.
The monoterpenes α(+)-pinene (plus some optical and positional isomers) and a-terpinene activated a separate cell type, whereas benzaldehyde stimulated the same receptor as hexanal, but with a higher threshold. Furthermore, an olfactory cell selectively tuned to the perception of the male sex pheromone of this species was also found in the ascoid sensillum.     

Sand fly fauna (Diptera: Psychodidae) from the Goytacazes National Forest and surrounding areas of southeastern Brazil

Most studies of the sand fly fauna in southeastern Brazil are conducted in the peridomiciliary environment of leishmaniasis endemic regions. Therefore, to increase the knowledge about diversity and richness of sand fly conservation areas, we describe here the sand fly fauna from the National Forest of Goytacazes (NFG), state of Espírito Santo, Brazil, and its surroundings areas. We also used sand fly fauna records from eight conservations units within the state of Espírito Santo to understand the similarity and relationships among them. The sand flies were simultaneously collected from June, 2008 to May, 2009 in two different environments: a preserved environment represented by the NFG and a modified environment represented by a peridomicile. To establish the similarity among the conservation units, we used a method very similar to parsimony analysis of endemism. We collected 2,466 sand fly specimens belonging to 13 species. Pressatia choti and Nyssomyia intermedia were the most abundant sand fly species. Ny. intermedia is a known vector of Leishmania braziliensis and epidemiological surveillance must be conducted in the area. We discuss aspects regarding the diversity of sand flies as well as the risk of transmission of Leishmania parasites in the area. We also provide for the first time a hypothesis of similarity relationships among conservation units within the state of Espírito Santo.     

Evaluation of light-emitting diodes as attractant for sandflies (Diptera: Psychodidae: Phlebotominae) in northeastern Brazil

Hoover Pugedo light traps were modified for use with green and blue-light-emitting diodes to trap phlebotomine sandflies in northeastern Brazil. A total of 2,267 specimens belonging to eight genera and 15 species were sampled. The predominant species were Nyssomyia whitmani(34.41%) and Micropygomyia echinatopharynx(17.25%).The green LED trap prevailed over the blue and control lights; however, no statistically significant difference could be detected among the three light sources. Even without statistical significance, we suggest using LEDs as an attractant for the capture of sandflies because of several advantages over the conventional method with incandescent lamps.     

Species composition and seasonal abundance of sandflies (Diptera: Psychodidae: Phlebotominae) in coffee agroecosystems

The composition and seasonal occurrence of sandflies were investigated in coffeeagroecosystems in the Soconusco region of Chiapas, Mexico. Insect sampling wasperformed on three plantations located at different altitudes: Finca Guadalupe Zajú[1,000 m above sea level (a.s.l.)], Finca Argovia (613 m a.s.l.) and Teotihuacán delValle (429 m a.s.l.). Sandflies were sampled monthly from August 2007-July 2008 usingthree sampling methods: Shannon traps, CDC miniature light traps and Disney traps.Sampling was conducted for 3 h during three consecutive nights, beginning at sunset.A total of 4,387 sandflies were collected during the course of the study: 2,718individuals in Finca Guadalupe Zajú, 605 in Finca Argovia and 1,064 in Teotihuacándel Valle. The Shannon traps captured 94.3% of the total sandflies, while the CDClight traps and Disney traps captured 4.9% and 0.8%, respectively. More females thanmales were collected at all sites. While the number of sandflies captured waspositively correlated with temperature and relative humidity, a negative correlationwas observed between sandfly numbers and rainfall. Five species of sandflies werecaptured: Lutzomyia cruciata , Lutzomyia texana ,Lutzomyia ovallesi , Lutzomyia cratifer /undulata and Brumptomyia sp. Lu.cruciata , constituting 98.8% of the total, was the most abundantspecies. None of the captured sandflies was infected with Leishmaniaspp.     

Rivers as islands: determinants of the distribution of Andean astroblepid catfishes

The distribution of astroblepids was examined using predictive niche modelling techniques to explore the physical and environmental factors responsible for determining the limits to their geographic distribution in the tropical Andes. Astroblepids occur in streams across a wide range of elevations (100-4600 m) and ecosystems from Panama to Bolivia, with most occurrences between 500 and 2000 m and associated with a narrow range of mean temperatures (17-24° C). The Maxent-predicted distribution was 83% accurate, statistically significant (AUC = 0·965), and closely matched the known distribution, with few notable exceptions. Four environmental variables contributed a cumulative 84% to the prediction, with elevation the most important, followed by temperature seasonality, isothermality and maximum temperature of the warmest month. The greatest discrepancy between the predicted and known distributions involved areas of predicted habitat suitability where there are no associated occurrence records. A jackknife test of variable contribution to the model showed that elevation contributed to the predicted distribution in ways not simply accounted for by temperature. Contrary to expectations, land cover type and vegetation characteristics contributed relatively little to the model prediction.     

Demographic history and the low genetic diversity in Dipteryx alata (Fabaceae) from Brazilian Neotropical savannas

Genetic effects of habitat fragmentation may be undetectable because they are generally a recent event in evolutionary time or because of confounding effects such as historical bottlenecks and historical changes in species'' distribution. To assess the effects of demographic history on the genetic diversity and population structure in the Neotropical tree Dipteryx alata (Fabaceae), we used coalescence analyses coupled with ecological niche modeling to hindcast its distribution over the last 21 000 years. Twenty-five populations (644 individuals) were sampled and all individuals were genotyped using eight microsatellite loci. All populations presented low allelic richness and genetic diversity. The estimated effective population size was small in all populations and gene flow was negligible among most. We also found a significant signal of demographic reduction in most cases. Genetic differentiation among populations was significantly correlated with geographical distance. Allelic richness showed a spatial cline pattern in relation to the species'' paleodistribution 21 kyr BP (thousand years before present), as expected under a range expansion model. Our results show strong evidences that genetic diversity in D. alata is the outcome of the historical changes in species distribution during the late Pleistocene. Because of this historically low effective population size and the low genetic diversity, recent fragmentation of the Cerrado biome may increase population differentiation, causing population decline and compromising long-term persistence.