The Asian tiger mosquito, Aedes albopictus, is currently the most widespread invasive mosquito species in the world. It poses a significant threat to human health, as it is a vector for several arboviruses. We used a SNP chip to genotype 748 Ae. albopictus mosquitoes from 41 localities across Europe, 28 localities in the native range in Asia, and 4 in the Americas. Using multiple algorithms, we examined population genetic structure and differentiation within Europe and across our global dataset to gain insight into the origin of the invasive European populations. We also compared results from our SNP data to those obtained using genotypes from 11 microsatellite loci (N = 637 mosquitoes from 25 European localities) to explore how sampling effort and the type of genetic marker used may influence conclusions about Ae. albopictus population structure. While some analyses detected more than 20 clusters worldwide, we found mosquitoes could be grouped into 7 distinct genetic clusters, with most European populations originating in East Asia (Japan or China). Interestingly, some populations in Eastern Europe did not share genetic ancestry with any populations from the native range or Americas, indicating that these populations originated from areas not sampled in this study. The SNP and microsatellite datasets found similar patterns of genetic differentiation in Europe, but the microsatellite dataset could not detect the more subtle genetic structure revealed using SNPs. Overall, data from the SNP chip offered a higher resolution for detecting the genetic structure and the potential origins of invasions.

Background Although whole-genome sequencing (WGS) is the preferred genotyping method for most genomic analyses, limitations are often experienced when studying genomes characterized by a high percentage of repetitive elements, high linkage, and recombination deserts. The Asian tiger mosquito ( Aedes albopictus ), for example, has a genome comprising up to 72% repetitive elements, and therefore we set out to develop a single-nucleotide polymorphism (SNP) chip to be more cost-effective. Aedes albopictus is an invasive species originating from Southeast Asia that has recently spread around the world and is a vector for many human diseases. Developing an accessible genotyping platform is essential in advancing biological control methods and understanding the population dynamics of this pest species, with significant implications for public health. Methods We designed a SNP chip for Ae. albopictus (Aealbo chip) based on approximately 2.7 million SNPs identified using WGS data from 819 worldwide samples. We validated the chip using laboratory single-pair crosses, comparing technical replicates, and comparing genotypes of samples genotyped by WGS and the SNP chip. We then used the chip for a population genomic analysis of 237 samples from 28 sites in the native range to evaluate its usefulness in describing patterns of genomic variation and tracing the origins of invasions. Results Probes on the Aealbo chip targeted 175,396 SNPs in coding and non-coding regions across all three chromosomes, with a density of 102 SNPs per 1 Mb window, and at least one SNP in each of the 17,461 protein-coding genes. Overall, 70% of the probes captured the genetic variation. Segregation analysis found that 98% of the SNPs followed expectations of single-copy Mendelian genes. Comparisons with WGS indicated that sites with genotype disagreements were mostly heterozygotes at loci with WGS read depth < 20, while there was near complete agreement with WGS read depths > 20, indicating that the chip more accurately detects heterozygotes than low-coverage WGS. Sample sizes did not affect the accuracy of the SNP chip genotype calls. Ancestry analyses identified four to five genetic clusters in the native range with various levels of admixture. Conclusions The Aealbo chip is highly accurate, is concordant with genotypes from WGS with high sequence coverage, and may be more accurate than low-coverage WGS. Graphical Abstract

Flies of the family Psychodidae are widespread and taxonomically diverse. The subfamily Psychodinae contains approximately 4,000 species and has little economic or medical importance. Its most well-known species are the moth flies Psychoda alternata and Clogmia albipunctata due to their widespread association with house drainpipes and sewage treatment plants. The subfamily Phlebotominae, commonly known as sand flies, with nearly 1,000 members, is of high medical importance because of their blood feeding and ability to transmit causative agents of human and animal diseases. Genera of medical importance are Lutzomyia sensu latu confined to the Americas and Phlebotomus distributed throughout the Old World. Leishmaniasis, the major disease, affects an estimated 12 million people worldwide. Other important diseases for which they serve as vectors include vesicular stomatitis, sand fly fever, and bartonellosis. Two phlebotomine species, Lutzomyia longipalpis and Phlebotomus papatasi, are particularly well known because of their ease in colonization and their critical roles in leishmaniasis transmission. Depending on locality and the occurrence of various forms of leishmaniasis, several dozen other phlebotomine species also can be involved as competent vectors.

The population genetic structure of Lutzomyia verrucarum (Townsend), a sand fly disease vector of Carrion's disease and cutaneous leishmaniasis in the Peruvian Andes, was characterized by sequencing 653 bp of cytochrome b and 1,125 bp of the NADH dehydrogenase subunit 4 genes of its mitochondrial genome. DNA sequence variation within and between valleys was compared in a sample of 220 sand flies from three valleys (Purisima, Huaylas, and Conchucos) and five departments (Amazonas, Cajamarca, Piura, Lima, and Huancavelica). Gene network and phylogenetic analyses indicated a high similarity of haplotypes collected within a single valley (0-0.52% nucleotide divergence). Flies from each valley had unique genotypes not shared with specimens from other valleys or from more distant regions (0.8-3.1% nucleotide divergence). Mountain ranges and geographic distance appear to have impeded migration (N(m) = < 0.18) between valleys and separated populations into discrete genetic units.

Museums play a vitally important role in supporting both informal and formal education and are important venues for fostering public understanding of evolution. The Yale Peabody Museum has implemented significant education programs on evolution for many decades, mostly focused on the museum’s extensive collections that represent the past and present tree of life. Twelve years ago, the Peabody began a series of new programs that explored biodiversity and evolution as it relates to human health. Modern evolutionary theory contributes significantly to our understanding of health and disease, and medical topics provide many excellent and relevant examples to explore evolutionary concepts. The Peabody developed a program on vector-borne diseases, specifically Lyme disease and West Nile virus, which have become endemic in the United States. Both of these diseases have complex transmission cycles involving an intricate interplay among the pathogen, host, and vector, each of which is subject to differing evolutionary pressures. Using these stories, the museum explored evolutionary concepts of adaptation (e.g., the evolution of blood feeding), coevolution (e.g., the “arms race” between host and vector), and variation and selection (e.g., antibiotic resistance) among others. The project included a temporary exhibition and the development of curriculum materials for middle and high school teachers and students. The popularity of the exhibit and some formal evaluation of student participants suggested that this educational approach has significant potential to engage wide audiences in evolutionary issues. In addition it demonstrated how natural history museums can incorporate evolution into a broad array of programs.

A description is presented of Lutzomyia tolimensis sp. nov., a new species of the subgenus Helcocyrtomyia, series sanguinaria. It was collected in dwellings, peridomestic environment and in nearby forest patches located in the foothills of the Andean Central Cordillera, where in 2004-2006 occurred the largest epidemic ever recorded of leishmaniasis in Colombia. The male of this species is differentiated from other members of the series sanguinaria based on the following combination of characters: (i) base of coxite with 0-3 subequal setae, (ii) spines of gonostyle organized in positions 2.1.2, (iii) spines inserted on distal half of gonostyle and (iv) relationship of alar indices. The female is recognized principally by the following characters: (i) palpomere V longer than III, (ii) length of labro-epipharynx and (iii) relationship of the alar indices.

Introduction. Since entomological surveillance is the main control strategy for visceralleishmaniasis, updated information on the distribution and ecology of involved vector species isnecessary for planning preventive measures. Objective. To present the updated and geo-referenced distribution of L. longipalpis and L.evansi, vectors of visceral leishmaniasis in Colombia, considering their relationship with their habitat. Materials and methods. Distribution was estimated from records of the sand fly specimenscollected since 1967.The information was organized in a database from which the localitieswere selected and geographically analyzed with Arc view in order to develop the distributionmaps.Results. 40 localities were established for L. longipalpis along the upper (24), middle (11) andlower (5) Magdalena river valley. L. evansi was recorded in 19 localities of the middle (5) andlower (14) Magdalena valley. Conclusions. Both species showed consistent association with dry tropical forest (sensuHoldridge 1967), confirming the epidemiological risk for visceral leishmaniasis in these areas.

Nineteen Aedes aegypti larvae were collected in rural Antigua, West Indies, from an 18-liter plastic bucket. The location was in a rural area at the northern end of Antigua bordering the coast of Dickenson Bay and approximately 50 m south of Halcyon Cove Beach (17 degrees 09'42.54 '' N, 61 degrees 50'44.50 '' W; elevation 16 m). Atypical morphology was noted in larvae and 3 reared adult females. Fourth instars showed a reduction in length of the lateral hair on the saddle (seta 1-X) with measurements ranging from 0.36 to 0.57 the length of the saddle. Two atypical female specimens displayed an abundance of dull white to gold scales that blanketed the abdomen. A 3rd specimen bore fine, golden scales on the mesonotum and bronze scales on the vertices of the head. These adult specimens demonstrated morphological characteristics that closely parallel described mutations, although the genetic basis for these characters was not confirmed. The remaining adults in the collection were morphologically typical. Adults and larvae were compared to field populations from Florida, Bahamas, and Antigua, as well as to the Rockefeller strain maintained at Rutgers University.

Peridomestic transmission of American cutaneous leishmaniasis is increasingly reported and dogs may be a reservoir of Leishmania (Viannia) in this setting. We investigated the prevalence of infection in dogs in Chaparral County, Colombia, the focus of an epidemic of human cutaneous leishmaniasis caused by Leishmania (Viannia) guyanensis. Two (0.72%) of 279 dogs had lesions typical of cutaneous leishmaniasis that were biopsy positive by kinetoplast DNA polymerase chain reaction-Southern blotting. Seroprevalence was 2.2% (6 of 279) by enzyme-linked immunosorbent assay. Buffy coat and ear skin biopsy specimens were positive by polymerase chain reaction-Southern blotting in 7.3% (10 of 137) and 11.4% (12 of 105) of dogs, respectively. Overall 20% of dogs (21 of 105) showed positive results for one or more tests. Amplification and sequencing of the Leishmania 7SL RNA gene identified L. guyanensis in one dog and L. braziliensis in two dogs. No association was identified between the risk factors evaluated and canine infection. Dogs may contribute to transmission but their role in this focus appears to be limited.

Phlebotomine vector ecology was studied in the largest recorded outbreak of American cutaneous leishmaniasis in Colombia in 2004. In two rural townships that had experienced contrasting patterns of case incidence, this study evaluated phlebotomine species composition, seasonal abundance, nocturnal activity, blood source, prevalence of Leishmania infection, and species identification. CDC miniature light traps were used to trap the phlebotomines. Traps were set indoors, peridomestically, and in woodlands. Natural infection was determined in pools by polymerase chain reaction-Southern blot, and blood sources and species identification were determined by sequencing. Large differences were observed in population abundance between the two townships evaluated. Lutzomyia longiflocosa was the most abundant species (83.1%). Abundance was higher during months with lower precipitation. Nocturnal activity was associated with human domestic activity. Blood sources identified were mainly human (85%). A high prevalence of infection was found in L. longiflocosa indoors (2.7%) and the peridomestic setting (2.5%). L. longiflocosa was responsible for domestic transmission in Chaparral.

Within the sand fly genus Lutzomyia, the Verrucarum species group contains several of the principal vectors of American cutaneous leishmaniasis and human bartonellosis in the Andean region of South America. The group encompasses 40 species for which the taxonomic status, phylogenetic relationships, and role of each species in disease transmission remain unresolved. Mitochondrial cytochrome c oxidase I (COI) phylogenetic analysis of a 667-bp fragment supported the morphological classification of the Verrucarum group into series. Genetic sequences from seven species were grouped in well-supported monophyletic lineages. Four species, however, clustered in two paraphyletic lineages that indicate conspecificity—the Lutzomyia longiflocosa–Lutzomyia sauroida pair and the Lutzomyia quasitownsendi–Lutzomyia torvida pair. COI sequences were also evaluated as a taxonomic tool based on interspecific genetic variability within the Verrucarum group and the intraspecific variability of one of its members, Lutzomyia verrucarum, across its known distribution.

Environmental risk factors for cutaneous leishmaniasis were investigated for the largest outbreak recorded in Colombia. The outbreak began in 2003 in Chaparral, and in the following five years produced 2,313 cases in a population of 56,228. Candidate predictor variables were land use, elevation, and climatic variables such as mean temperature and precipitation. Spatial analysis showed that incidence of cutaneous leishmaniasis was higher in townships with mean temperatures in the middle of the county's range. Incidence was independently associated with higher coverage with forest or shrubs (2.6% greater for each additional percent coverage, 95% credible interval [CI] = 0.5-4.9%), and lower population density (22% lower for each additional 100 persons/km(2), 95% CI = 7-41%). The extent of forest or shrub coverage did not show major changes over time. These findings confirmed the roles of climate and land use in leishmaniasis transmission. However, environmental variables were not sufficient to explain the spatial variation in incidence.

Aedes albopictus (Skuse) (Diptera: Culicidae), the Asian tiger mosquito indigenous to Asia, now an invasive species worldwide, is an important vector for several arboviruses. Genetic analysis using the mitochondrial nicotinamide adenine dinucleotide dehydrogenase subunit 5 (ND5) gene was carried out in populations from Cameroon (n = 50), Hawaii (n = 38), Italy (n = 20), the continental United States, Brazil, and its native range. Data for Brazil, the continental United States, and the native range was obtained from Birungi and Munstermann (2002). Direct sequencing was used to identity unique haplotypes. The limited phylogeographic partitioning of haplotypes with low levels of sequence divergence in both Cameroon and Hawaii was consistent with the population structure of Ae. albopictus in the United States and Brazil. Four new haplotypes were identified from the samples from Cameroon and Hawaii, adding to previously described haplotypes. Hawaii shared a haplotype with Cameroon that was unique to these two regions. Hawaii also had higher overall haplotype diversity than seen in previous continental United States, Brazil, or native range populations. Hawaiian, Cameroon, and Italian populations did not share haplotypes with Brazil, which validates the earlier mitochondrial DNA studies indicating a separate introduction of this species into Brazil.

Sixteen isoenzyme patterns were analyzed for five Colombian Lutzomyia species. The average unbiased expected heterozygosity levels ranged from 0.098 (Lu. youngi) to 0.215 (Lu. torrvida). The five species samples, taken all the isoenzymes employed, were significantly deviated from the Hardy-Weinberg equilibrium by homozygous excess with classical as well as Markov chain exact tests. Possible causes: (1) Wahlund effect within populations due to subdivision and/or sampling. Endogamy could be discarded because these loci were affected by highly different levels of homozygous excess. (2) Null alleles could be not discarded, at least for some isoenzymes. The hierarchical Wright's F analysis showed high and significant values for each parameter. The average F(IT) value was 0.655 with a conspicous homozygous excess at a global level (all species taken together); the average F(IS) value was significantly positive (0.515) as well, with homozygous excess within each species. The genetic heterogeneity between the fives species was noteworthy (F(ST) 0.288), indicating clear genetic differentiation. The more related species pairs were Lu. longiflocosa-Lu. torvida (0.959) and Lu torvida-Lu. spinicrassa (0.960); while Lu. torvida-Lu. youngi (0.805) and Lu. quasitownsendi-Lu. youngi (0.796) were the most divergent (Nei's genetic identity matrix). UPGMA and Wagner algorithms showed that the most divergent species was Lu. youngi, whereas the most related were Lu. longiflocosa-Lu. torvida and Lu torvida-Lu. spinicrassa. A spatial autocorrelation analysis (Moran's I index) revealed a very weak, or inexistent spatial structure, which means that the speciation events between these species were independent from the geographic distances from where they currently live.

In a climate of increased funding for vaccines, chemotherapy, and prevention of vector-borne diseases, fewer resources have been directed toward improving disease and vector surveillance. Recently developed light-emitting diode (LED) technology was applied to standard insect-vector traps to produce a more effective lighting system. This approach improved phlebotomine sand fly capture rates by 50%, and simultaneously reduced the energy consumption by 50-60%. The LEDs were incorporated into 2 lighting designs, 1) a LED combination bulb for current light traps and 2) a chip-based LED design for a modified Centers for Disease Control and Prevention light trap. Detailed descriptions of the 2 designs are presented.

Increasing instances of epidemic outbreaks of cutaneous leishmaniasis in the Americas (ACL) have pointed to a changing epidemiological pattern from transmission centered in the forest to transmission foci within peridomestic environments. An epidemic occurrence of ACL in the Tolima Province of Colombia led to the development of a project to assess the relative roles of the environment, the insect vector, the vertebrate reservoir, and the human in the transmission cycle. This information was necessary to satisfy the demands of two objectives: (1) to establish the boundaries of a risk map for ACL transmission and (2) detect points at which a transmission cycle may be prevented or interrupted. The investigation centered on two townships, one located near the center of the epidemic zone--satisfied criteria of habitat variety, large number of cases and accessibility. A nearby nonepidemic township was selected as a reference control that appeared equivalent in terms of environment and demography but without leishmaniasis transmission. ASTER satellite images of each township were compared for 16 spectral characteristics that were highly correlated with the physical environment, including vegetation structure, water quantity and temperature. Epidemic and control townships were compared with the following data: (1) 8 supervised classifications that included forest, cultivation, grassland and urban; (2) fourteen climatic layers obtained from Worldclim (www.worldclim.org); and (3) incidence and prevalence data from local hospitals—demographic data from the Colombian government agency (SIBEN). Main association with leishmaniasis cases was effect of adjacent forest/scrub vegetation. Case incidence was 34% higher for each 10% increase in woodland cover. Second, seasons of high and low temperature were least conducive to appearance of ACL cases. Extensive trapping for reservoir feral animals was not highly productive. However, approximately equal numbers were captured in control and epidemic areas. The preponderant animal at both sites was the opossum, Didelphus marsupialis. Of the 39 total animals tested by PCR with Leishmania-specific kDNA primers, only one opossum and one unidentified rodent were positive. The low animal numbers and preliminary generally negative PCR tests indicate that feral animals play only a small role in epidemic transmission. In contrast, domestic animals were more abundantly sampled—a dog sample of 278 indicated high numbers of antibody positive canines. In a 2-year collection of the presumptive vector, the phlebotomine sand fly, approximately 8,800 flies were collected. (1) 53 x as many flies were found in the epidemic townships in contrast to the control region (8,650 vs 161). The monthly collections paralleled the transect collections. (2) Substantial seasonal variation was observed with two notable peaks--Aug-Sept and in Jan-Feb. Flies collected in peak months ranged from 838 to 3,143 flies, whereas in the non-peak months the range was 153-573. (3) Species composition: Lutzomyia longiflocosa (65%); Lu. trinidadensis (25%); Helcocyrtomyia spp. (8%); Lu. nuneztovari (<1%); Lu. columbiana (<1%); unidentified species (1%). The species were quite evenly distributed amongst the habitats with the following exceptions. Lu.trinidadensis was rarely found inside houses, but always in peridomestic and forest collections. Lu. columbiana was collected at all seasons in approximately equal numbers, albeit always <10 / month. The Lu.trinadadensis is typically not a human feeder and is unlikely to be involved in leishmania transmission. In summary, the Tolima epidemic involves a combination of the following contributory factors: (1) higher density scrub and forest vegetation, (2) very high densities of sand flies, and (3) high density of a putative vector, Lu.longiflocosa. The paucity of wild animal reservoirs pointed to a domestic animal reservoir, with dogs as a probable important source, and enhanced the probability of a human to sand fly to human transmission cycle. The atypical characters of this epidemic were the implied vector species Lu. longiflocosa (a rarely documented species), and the domesticity of transmission that may involve a domestic reservoir (dog) and possibly a human to sand fly to human route.