Blackfly fever and dermatitis caused by Simulium kiritshenkoi: a human case report in Iran.

BACKGROUND: Besides the considerable role of blackflies to the transmission of many disease agents, these flies considered as annoying biting pests of wildlife, livestock, poultry, and humans. There are few literature reports of blackfly fever following Simulium spp. This study describes a case of blackfly fever and dermatitis following blackflies numerous bites in Iran. CASE PRESENTATION: The present report describes a 25-year-old man that was attacked by numerous flies while fishing and camping near Namrood river in Firuzkuh County, Tehran Province, Iran. Pruritic dermatitis with marked edema appeared mainly on the hands and legs and subsequently, the patient's condition worsened with swollen lymph nodes, joints aching, and 40 °C fever. The patient's clinical signs and symptoms were alleviated by injection of intramuscular Dexamethasone Phosphate (DEXADIC®) 8 mg/2 ml after 24 h. CONCLUSIONS: This study reported a human case with blackfly fever and dermatitis following numerous bites of Simulium kiritshenkoi, for the first time in Iran.

Community Perceptions of Blackfly Nuisance and Acceptability of the "Slash and Clear" Vector Control Approach in the Ntui Health District of Cameroon: A Qualitative Study.

Besides being vectors of the onchocerciasis parasite, blackflies are a source of nuisance in onchocerciasis-endemic communities. We investigated the experience of residents in the Ntui Health District (Cameroon) regarding blackfly nuisance and assessed their perceptions of a novel "Slash and Clear" (S&C) intervention for blackfly control. Focus group discussions were conducted before and after S&C implementation (respectively, in February 2022 and December 2023). Blackflies were known to emerge from the river areas and cause disease. To prevent blackfly bites, the population often covered their body with protective clothing and applied various substances (kerosene, oil, or lemon) to their skin. Post-intervention data showed reduced blackfly nuisance, and the willingness to sustain blackfly control in the long-term was unanimous among community leaders and members, including the village volunteers who implemented the S&C intervention. In conclusion, blackfly nuisance is evident in the Ntui onchocerciasis focus of Cameroon and led to a panoply of coping practices, some of which could be detrimental to their health. Implementing S&C for blackfly control is well accepted and could sustainably alleviate the nuisance caused by blackflies while simultaneously breaking the onchocerciasis transmission cycle.

Trends in black fly density, parity and infection rates from riverside to villages of the Bafia Health District in Cameroon: implication for onchocerciasis vector control.

BACKGROUND: Reducing contact between humans and black flies can lead to interruption of onchocerciasis transmission. The Esperanza Window Trap (EWT) has been shown to be an effective tool for reducing black fly densities. Several shape-based improvements to this trapping system have been made to optimise its effectiveness, but optimisation of this trapping system has been based most often on the shape of the trap, collection in areas of high black fly density and the addition of attractants, without considering transmission potentials and parity rates. This study aims to investigate the differences in biting rates and transmission potential between three catch points along a transect to guide the choice of EWT placement. METHODS: Monthly black fly collection was carried out over a 1-year study period using the human landing method at three catch points along a transect from the riverside toward the centre of two first-line villages (Biatsota and Bayomen), in the Mbam valley in Cameroon. All female black flies caught were counted and dissected, and entomological indicators were computed and compared between the catch points and villages. RESULTS: A total of 80,732 black flies were caught, of which 57,517 were dissected; of the latter, 2743 (4.8%) were parous and 44 (1.6%) were infective. Regarding the distance to the river, a vector density gradient was observed, with the highest annual biting rates being recorded at the riverside. The highest annual transmission potentials were also recorded at the riverside (165 vs 255 infective larvae/man/year in Bayomen and Biatsota, respectively). Overall, the highest parity rates were recorded at the riverside in Biatsota (5.1%) where various human activities are frequent and at the centre of Bayomen village (6.3%). CONCLUSION: The results of this study reveal that entomological parameters were the highest at the riverside catch sites and indicate that riverside locations should be prioritised for EWTs or other trapping systems to achieve optimal performance in onchocerciasis control.

Comparison of standard and modified human landing catching techniques for blackfly collection.

BACKGROUND: Human landing catches (HLCs) are required to collect blackflies for entomological evaluation to verify onchocerciasis elimination. However, there are ethical concerns regarding exposure of vector collectors to infectious blackflies and safer alternative methods are needed. This study evaluated a modified HLC technique where collectors wore coloured trousers (blue, black or blue-black), protecting them from bites during fly collection, and their performance was compared with the standard. METHODS: The study was conducted in Makouopsap, Cameroon, in the Massangam health district for 4 months. Four collector pairs-one 'standard' (bare-legged) and three modified-were placed 50 m apart along known breeding sites on the Mbam and Nja Rivers. Collections were performed from 07:00 to 17:00 h, 4 d/month. Hourly rates of flies caught were analysed using a negative binomial generalised linear model to explore associations between flies caught and collection techniques and seasons. RESULTS: Overall, 17 246 blackflies were caught. There was no significant statistical difference in the number of blackflies and parous flies caught between black trousers and the standard. Thus there is a strong indication that wearing black trousers is a viable non-inferior alternative to the standard HLC. CONCLUSIONS: Further studies are needed to confirm generalisability in different ecozones and transmission environments and among different blackfly species.

A Survey in Hawaii for Parasitoids of Citrus Whiteflies (Hemiptera: Aleyrodidae), for Introduction into Greece.

Whitefly species of Aleurocanthus spiniferus (Quaintance) and A. woglumi Ashby (Hemiptera: Aleyrodidae) are serious pests of citrus and other important fruit crops. The problem of citrus has initiated the successful introduction of several natural enemies for biocontrol programs in Hawaii and many other countries. Here, we summarized the history of infestation and biocontrol efforts of the two whiteflies in Hawaii for possible parasitoid importation into Greece. Two Platygasteridae (Amitus hesperidum Silvestri, A. spiniferus (Brethes), and three Aphelinidae (Encarsia clypealis (Silvestri), E. smithi (Silvestri), E. perplexa Huang, and Polaszek) were released in Hawaii for biocontrol of the citrus whiteflies during the period 1974-1999. The aphelinid Cales noacki Howard, purposely released for Aleurothrixus flococcus (Maskell) in 1982, was also reported to attack other whiteflies, including Aleurocanthus species, on citrus. An additional aphelinid parasitoid, Encarsia nipponica Silvestri, native to Japan and China, was accidentally introduced and found to attack both citrus whiteflies on the islands. Since the colonization of introduced parasitoids in infested fields on four Hawaiian Islands, no survey has been conducted to evaluate their potential impact. We conducted two short surveys during September-November 2022 on the islands of Kauai, Hawaii, and Oahu to introduce the dominant parasitoids to Greece for the biocontrol of A. spiniferus. Results showed that the infestation level was very low on Kauai, Hawaii, and Oahu Islands, with a mean infestation level range of 1.4-3.1 on Hawaii and Oahu Islands, mostly on pummelo and sweet orange, with no detection on the island of Kauai. The dominant parasitoid was characterized as Encarsia perplexa, using molecular analysis. Its parasitism rates ranged from 0 to 28% on the island of Hawaii and 11 to 65% on the island of Oahu. Emerged parasitoids have been reared in Greece for evaluation. This was the first field survey of Hawaii since the introduction and release of citrus whitefly natural enemies.

Presumed Onchocerciasis Chorioretinitis Spilling over into North America, Europe and Middle East.

BACKGROUND: Newer generation ophthalmologists practicing in the developed world are not very familiar with some tropical ocular diseases due to the absence of reports in the ophthalmic literature over the past thirty years. Because of world globalization or due to influx of immigrants from sub-Saharan Africa, exotic retinal diseases are being encountered more often in ophthalmology clinics. METHODS: A multicenter case series of chorioretinitis or optic neuritis with obscure etiology that used serial multimodal imaging. RESULTS: Four cases qualified with the diagnosis of presumed ocular onchocerciasis based on their residence near fast rivers in endemic areas, multimodal imaging, long term follow-up showing progressive disease and negative workup for other diseases. Characteristic findings include peripapillary choroiditis with optic neuritis or atrophy, subretinal tracts of the microfilaria, progressive RPE atrophy around heavily pigmented multifocal chorioretinal lesions of varying shapes, subretinal white or crystalline dots, and response to ivermectin. Typical skin findings are often absent in such patients with chorioretinitis rendering the diagnosis more challenging. CONCLUSIONS: Familiarity with the myriad ocular findings of onchocerciasis, and a high-degree of suspicion in subjects residing in endemic areas can help in the correct diagnosis and implementation of appropriate therapy. Onchocercal chorioretinitis is a slow, insidious, progressive, and prolonged polymorphous disease.

Risk of Attacks by Blackflies (Diptera: Simuliidae) and Occurrence of Severe Skin Symptoms in Bitten Patients along the Eastern Border of the European Union.

The components of blackfly (Diptera: Simuliidae) saliva secreted during feeding on humans and animals induce various pathological reactions manifested by skin lesions and systemic symptoms. In this study, we describe 43 cases of severe skin lesions induced by blackfly bites and analyze their potential causes. Based on the results of a survey of 418 patients, we identified periods with risk of blackfly attacks and their environmental determinants in the eastern part of the European Union. Especially strong inflammatory reactions after blackfly bites were reported in patients with concomitant cardiovascular diseases (mainly with venous insufficiency), metabolic diseases, and bacterial infections. Enhanced symptoms of simuliosis were also observed in other patients attacked by these insects only once or repeatedly. The greatest number of blackfly attacks in the study area is recorded from May to July, with a peak in June (38.73%) in the afternoon (37.10%) and evening (33.03%), when patients are in fields, forests, or their households. The case analysis indicates interactions of various factors in the development of severe inflammatory reactions in patients bitten by blackflies. Therefore, it is recommended that subjects exposed to the presence of blackflies during their work or rest should limit the length of their stay in a vulnerable environment during the highest seasonal and daily activity of these insects. It is also necessary to take measures to reduce the number of blackflies and popularize methods for prophylaxis of their attacks.

Differential effects of environmental climatic variables on parasite abundances in blue tit nests during a decade.

Models on climate change have predicted an increase of temperature over the earth's surface with potential drastic effects on living organisms. We analyzed the relationships between climatic conditions (temperature, rainfall, and wind speed) and the abundance of blood-sucking flying insects (biting midges and blackflies) and nest-dwelling ectoparasites (mites, fleas, and blowflies) collected from blue tit nests during bird breeding seasons for a period of 10 years. Average temperature, rainfall, and wind speed showed significant differences among years. Temperature and wind speed increased during the period of study while rainfall decreased. Biting midge, blackfly, and blowfly abundances increased across years but not flea and mite abundances. Hatching date decreased and brood size increased across years. Independently of year variation, parasites were related to climatic variables. For example, biting midge, blowfly, mite, and flea abundances were positive and significantly related to average temperature. We also found a positive and significant relationship between abundances of Haemoproteus infections and biting midge abundances during the first year of life of birds out of nests. However, abundance and prevalence of Lankesterella infections in yearlings were positive and significantly related to mite abundances during the year of birth of birds. Leucocytozoon and Lankesterella infections were also significantly related to climatic variables and Haemoproteus and Lankesterella infections increased across years. In addition, body condition of adult females and males were negatively related to flea larvae and blowfly abundance respectively. Nestling body condition was also negatively related to biting midge abundance. Changes in climatic conditions across years could therefore affect several parasites of birds but also to birds themselves.

Status of Onchocerca volvulus (Spirurida: Onchocercidae) Transmission and Effect of Climatic Variables on the Vector Population Dynamics After Two Decades of Ivermectin-based Preventive Chemotherapy in the Mbam Valley (Centre Region, Cameroon).

Entomological indicators of onchocerciasis transmission and the effect of climatic variables on the vector population dynamics were investigated in two first-line villages after more than two decades of mass drug administration with ivermectin. Female blackflies were collected in two villages (Bayomen and Biatsota) using human landing method for a period of 12 months. Blackflies were dissected and entomological indices were computed. Monthly temperature, precipitation, and humidity were collected and the Spearman correlation rank test was used to assess the relationship between biting rates and climatic variables. The highest biting rates (62,280 bites/human/month in Bayomen and 42,090 bites/human/month in Biatsota) were recorded during the long rainy season (November). The Onchocerca volvulus transmission was greater during the long dry season in both villages, with a peak at the beginning of the long dry season in Biatsota (100 infective larvae/human/month), and at the middle of the long dry season in Bayomen (92 infective larvae/human/month). No correlation was found between biting rates and selected climatic variables in the two villages. This study revealed that onchocerciasis transmission is ongoing in the study area despite almost 25 years of Community-Directed Treatment with Ivermectin. In accordance with WHO recommendations, vector control should be used in combination with mass drug administration to accelerate transmission interruption of onchocerciasis. To be optimal, this vector control should be implemented during the long dry season (November to March) when water volumes are low and transmission potentials are high.

Occurrence and Characterization of Small Microplastics (<100 µm), Additives, and Plasticizers in Larvae of Simuliidae

This study is the first to investigate the ingestion of microplastics (MPs), plasticizers, additives, and particles of micro-litter < 100 µm by larvae of Simuliidae (Diptera) in rivers. Blackflies belong to a small cosmopolitan insect family whose larvae are present alongside river courses, often with a torrential regime, up to their mouths. Specimens of two species of blackfly larvae, Simulium equinum and Simulium ornatum, were collected in two rivers in Central Italy, the Mignone and the Treja. Small microplastics (SMPs, <100 µm), plasticizers, additives, and other micro-litter components, e.g., natural and non-plastic synthetic fibers (APFs) ingested by blackfly larvae were, for the first time, quantified and concurrently identified via MicroFTIR. The pretreatment allowed for simultaneous extraction of the ingested SMPs and APFs. Strong acids or strong oxidizing reagents and the application of temperatures well above the glass transition temperature of polyamide 6 and 6.6 (55−60 °C) were not employed to avoid further denaturation/degradation of polymers and underestimating the quantification. Reagent and procedural blanks did not show any SMPs or APFs. The method's yield was >90%. Differences in the abundances of the SMPs and APFs ingested by the two species under exam were statistically significant. Additives and plasticizers can be specific to a particular polymer; thus, these compounds can be proxies for the presence of plastic polymers in the environment.

Skin Lesions and Systemic Reactions in Humans Infested by Blackflies (Diptera: Simullidae) in Recreational Areas in Southeastern Poland.

Due to their mass occurrence in some environments and high aggressiveness, blackflies (Simulium spp.) represent the most bothersome arthropods attacking humans. In this study, we describe the medical effects of blackfly infestations in humans in southeastern Poland. Local and systemic reactions to blackfly bites were monitored in 418 patients (61.24% of females and 38.76% of males) of medical centers. Only skin lesions at the site of the bites were found in 88.52% of the patients, whereas accompanying systemic reactions were diagnosed in 11.48%. The most common signs observed in the area of the bites were pruritus (94.74%), burning (55.02%), edema (44.02%), and erythema (40.91%). The skin lesions, which were most often grouped small papules and papular and purpuric lesions with a varied range, typically persisted for several days, or for several weeks in some patients. Statistical analyses confirmed that the persistence of the skin lesions did not depend on the sex of the patients and the number of blackfly infestations. The systemic reactions to the components of the blackfly saliva were manifested by headache, increased body temperature, arthralgia, lymphadenopathy, and menstrual disorders in the females. The patients were most often attacked simultaneously by many blackflies on exposed parts of the body, mainly the upper limb, lower limb, head, and neck areas. The investigations indicate that blackflies are an important etiological factor of dermatitis and other symptoms in humans; hence, they should be considered in clinical diagnosis.

Bacteriome Diversity of Blackflies' Gut and Association with Onchocerca volvulus, the Causative Agent of Onchocerciasis in Mbam Valley (Center Region, Cameroon).

Vector control using larvicides is the main alternative strategy to address limits of preventive chemotherapy using ivermectin for the control of onchocerciasis. However, it remains substantially limited by implementation difficulties, ecological concerns and the resistance of vector populations. Therefore, efficient and environmentally safe alternative control strategies are still needed. This study explores the composition of the blackfly bacteriome and its variability in the presence of Onchocerca volvulus infection, in order to determine their potential as a novel vector control-based approach to fight onchocerciasis. An entomological survey of a collection of samples was performed in the Bafia health district, a historical endemic focus for onchocerciasis in Cameroon. A total of 1270 blackflies were dissected and the infection rate was 10.1%, indicative of ongoing transmission of onchocerciasis in the surveyed communities. Sequencing process of blackflies' gut DNA for bacteria screening revealed 14 phyla and 123 genera, highlighting the diversity of gut blackflies bacterial communities. Eight bacteria formed the core of blackfly bacteriome and Wolbachia was the predominant genus with 73.4% of relative abundance of blackflies' gut bacterial communities. Acidomonas and Roseanomas genera were significantly abundant among infected blackflies (p = 0.01), whereas other genera such as Brevibacterium and Fructobacillus were associated with the absence of infection (p = 0.0009). Differences in gut bacterial distribution of blackflies according to their infection status by the parasite suggest a causal relationship between the bacteriome composition and the onset of blackflies' infection by O. volvulus or vice versa. Blackfly native bacteria are then potentially involved in infection by O. volvulus, either by facilitating or preventing the parasite infestation of the vector. These bacteria represent an interesting potential as a biological tool/target for a novel approach of vector control to fight onchocerciasis.

First Report of Aleurocanthus spiniferus on Ailanthus altissima: Profiling of the Insect Microbiome and MicroRNAs.

We report the first occurrence of the orange spiny whitefly (Aleurocanthus spiniferus; OSW) on the tree of heaven (Ailanthus altissima) in Bari, Apulia region, Italy. After our first observation in 2016, the infestation recurred regularly during the following years and expanded to the neighboring trees. Since then, we have also found the insect on numerous patches of the tree of heaven and other plant species in the Bari province. Nevertheless, the tree of heaven was not particularly threatened by the insect, so that a possible contribution by OSW for the control of such an invasive plant cannot be hypothesized hitherto. This work was also aimed at profiling the microbiome of OSW feeding on A. altissima. For this purpose, we used the denaturing gradient gel electrophoresis (DGGE) and the deep sequencing of small RNAs (sRNAs). Both techniques unveiled the presence of "Candidatus Portiera" (primary endosymbiont), Wolbachia sp. and Rickettsia sp., endosymbionts already reported for other Aleyrodidae. Deep sequencing data were analyzed by four computational pipelines in order to understand the reliability of the detection of fungi, bacteria, and viruses: Kraken, Kaiju, Velvet, and VelvetOptimiser. Some contigs assembled by Velvet or VelvetOptimiser were associated with insects, but not necessarily in the Aleurocanthus genus or Aleyrodidae family, suggesting the non-specificity of sRNAs or possible traces of parasitoids in the sample (e.g., Eretmocerus sp.). Finally, deep sequencing data were used to describe the microtranscriptome of OSW: 56 canonical and at least four high-confidence novel microRNAs (miRNAs) were identified. The overall miRNA abundance in OSW was in agreement with previous works on Bemisia tabaci, and bantam-3p, miR-276a-3p, miR-317-3p, miR-750-3p, and mir-8-3p were the most represented miRNAs.

Unravelling the Single-Stranded DNA Virome of the New Zealand Blackfly.

Over the last decade, arthropods have been shown to harbour a rich diversity of viruses. Through viral metagenomics a large diversity of single-stranded (ss) DNA viruses have been identified. Here we examine the ssDNA virome of the hematophagous New Zealand blackfly using viral metagenomics. Our investigation reveals a plethora of novel ssDNA viral genomes, some of which cluster in the viral families Genomoviridae (n = 9), Circoviridae (n = 1), and Microviridae (n = 108), others in putative families that, at present, remain unclassified (n = 20) and one DNA molecule that only encodes a replication associated protein. Among these novel viruses, two putative multi-component virus genomes were recovered, and these are most closely related to a Tongan flying fox faeces-associated multi-component virus. Given that the only other known multi-component circular replication-associated (Rep) protein encoding single-stranded (CRESS) DNA viruses infecting plants are in the families Geminiviridae (members of the genus Begomovirus) and Nanoviridae, it appears these are likely a new multi-component virus group which may be associated with animals. This study reiterates the diversity of ssDNA viruses in nature and in particular with the New Zealand blackflies.

Elimination of onchocerciasis from Colombia: first proof of concept of river blindness elimination in the world.

BACKGROUND: Onchocerciasis is a chronic parasitic infection originally endemic in 13 discrete regional foci distributed among six countries of Latin America (Brazil, Colombia, Ecuador, Guatemala, Mexico and Venezuela). In Colombia, this disease was discovered in 1965 in the Pacific Coast of the country. The National Onchocerciasis Elimination Program was established in 1993 with the aim of eliminating disease morbidity and infection transmission. In 2013, the World Health Organization (WHO) verified Colombia as free of onchocerciasis, becoming the first country in the world to reach such a goal. This report provides the empirical evidence of the elimination of Onchocerca volvulus transmission by Simulium exiguum (s.l.) after 12 years of 6-monthly mass drug administration of Mectizan® (ivermectin) to all the eligible residents living in this endemic area. METHODS: From 1996 onwards, a biannual community-based mass ivermectin administration programme was implemented, complemented by health education and community participation. In-depth parasitological, serological and entomological surveys were conducted periodically between 1998 and 2007 to evaluate the impact of ivermectin treatment according to the 2001 WHO guidelines. When the interruption of parasite transmission was demonstrated, the drug distribution ceased and a three-year post-treatment surveillance (PTS) period (2008-2010) was initiated. RESULTS: After 23 rounds of treatment, parasitological and ophthalmological assessments showed absence of microfilariae in skin and anterior chamber of the eyes. Serological tests proved lack of antibodies against O. volvulus in children under 10 years-old. A total of 10,500 S. exiguum flies tested by PCR had no L3 infection (infectivity rate = 0.0095%; 95% CI: 0.0029-0.049) during 2004, indicating interruption of parasite transmission. However, biannual ivermectin treatments continued until 2007 followed by a 3-year PTS period at the end of which 13,481 flies were analyzed and no infective flies were found (infectivity rate = 0%; 95% CI: 0.0-0.014). CONCLUSIONS: These results fulfilled the WHO criteria for onchocerciasis elimination. Consequently, in 2013 Colombia was verified as free of onchocerciasis, demonstrating that elimination of this neglected tropical disease is an achievable goal and paving the way for an elimination agenda to be followed by other endemic countries in Latin America and Africa.

DNA barcoding of blackflies (Diptera: Simuliidae) as a tool for species identification and detection of hidden diversity in the eastern regions of Spain.

BACKGROUND: Blackflies have negative impact on public and animal health due to the haematophagous habit of females. In recent times, in some regions in Spain, blackfly outbreaks are becoming more and more frequent, threatening the public health. However, there is still a paucity of data concerning the Spanish blackfly fauna. Correct identification of species is of paramount importance in order to provide correct information on species distribution, biology and behaviour, so that control measures could be implemented appropriately. METHODS: Blackflies specimens (larvae, pupae, reared adults and biting females) were collected in the period 2015-2017 in and near rivers and streams from different regions in Spain. A modified Hotshot technique was used for the DNA extraction and the cox1 DNA barcoding region of the cytochrome c oxidase subunit 1 was sequenced from the specimens collected. RESULTS: In total, we collected 239 specimens representing 22 species. Of these, six species are new records for the Aragón region: P. tomosvaryi, S. bertrandi, S. galloprovinciale, S. lineatum, S. rubzovianum and S. xanthinum. Cox1 DNA barcode sequences for 21 species were recovered, including four species of the genus Prosimulium and 17 species of the genus Simulium [Boophthora (1 species), Eusimulium (1 species), Nevermannia (4 species), Simulium (s.s.) (6 species), Trichodagmia (1 species) and Wilhelmia (4 species)]. For the first time the complete DNA barcodes for five species (P. tomosvaryi, S. carthusiense, S. brevidens, S. monticola and S. sergenti) were registered. Most of the specimens belonging to the same recognized species were clustered together in the neighbour-joining tree, except for S. argyreatum, S. monticola and S. variegatum. The overall genetic distance in the dataset was 0.14%. The average of the intraspecific genetic divergence within the different taxa was 1.47% (0.05-3.96%). In contrast, the interspecific divergence varied between 2.50-22.0%. CONCLUSIONS: In this study we assessed the use of the cox1 DNA barcoding region for the identification of species of blackflies in Spain. Our results showed that combining DNA barcoding with morphology enhanced our taxonomic rationale in identifying the blackflies in the country.

Biodiversity, seasonal abundance, and distribution of blackflies (Diptera: Simuliidae) in six different regions of Thailand.

BACKGROUND: Blackflies are an important medical and veterinary group of small blood-sucking insects. Ninety-three blackfly species have been reported in Thailand. However, information on their biodiversity and population dynamics in each region is lacking. The main aim of this study was to assess the regional biodiversity, seasonal abundance and distribution of blackflies in six eco-geographically different regions in the country. METHODS: Blackfly larvae and pupae were sampled monthly from 58 sites between May 2011 and April 2013. Diversity parameters, seasonal abundance, regional distribution and frequency of species occurrence in stream sites were analyzed. RESULTS: A total of 19,456 mature larvae representing 57 species, and belonging to six subgenera in the genus Simulium Latreille (s.l.), were found. The five predominant taxa were S. fenestratum (8.6%), the S. asakoae complex (8.3%), S. nakhonense (7.5%), the S. siamense complex (7.4%) and the S. doipuiense complex (6.7%). The most frequent taxa at all sites were the S. asakoae complex (84.5%), followed by S. fenestratum (82.8%), the S. siamense complex (75.9%), S. decuplum (60.3%), S. nakhonense (58.6%) and the S. tani complex (48.3%). The richness of regional species was highest (40 species) in the north and predominated in the cold season. However, blackflies in the south predominated during the hot season. The highest numbers of blackflies collected from central, northeastern, eastern and western regions of the country were observed in the rainy season. Overall, the mean number of blackflies collected across the six regions during the rainy and cold season had no statistically significant difference, but it differed significantly in the hot season. CONCLUSIONS: Blackflies in Thailand were surveyed in all three seasons across six geographical regions. These findings demonstrated that blackfly communities at each stream site varied with seasonality, and the regional relative abundance of blackflies differed markedly in the hot season. It was also found that the occurrence and distribution of blackflies in each region were associated strongly with elevation.

Human-landing rate, gonotrophic cycle length, survivorship, and public health importance of Simulium erythrocephalum in Zaragoza, northeastern Spain.

BACKGROUND: Simulium (Boophthora) erythrocephalum (De Geer, 1776) is one of the blackfly species responsible for major public health problems in Europe. Blackfly outbreaks of this species are becoming more frequent, threatening public health in Spain. In the present study, bionomic parameters of S. erythrocephalum in northeastern Spain were estimated. METHODS: Simulium erythrocephalum was collected from May through June 2015 in Zaragoza, Spain, using the human-landing-collection (HLC) method. Daily pattern of total and parous landing activity was estimated, as was the gonotrophic cycle (GC) length and survivorship (S) rate, using time series analysis. RESULTS: Host-seeking females of S. erythrocephalum showed a bimodal human-landing activity pattern, with a minor and major peak at dawn and dusk, respectively; there was a significant negative association between human daily landing rate and temperature (P = 0.003) and solar radiation (P < 0.001). Overall, a daily landing rate (DLR) of 34 lands/person/day was estimated. Series of sequential data analysis on parity showed the highest significant (P < 0.001) correlation indices (r = 0.45 and r = 0.39 for raw and filtered data) for a 2-day time lag, indicating that the GC length corresponded to 2 days. Daily survivorship and parity rate were 0.85 and 0.72, respectively. CONCLUSIONS: Simulium erythrocephalum was confirmed as a nuisance species in Zaragoza, using the HLC method for the first time in Spain. The data offer insights into the ecology of S. erythrocephalum, which can improve management strategies of this pest in Spain.

Sequence and organization of the complete mitochondrial genome of the blackfly Simulium variegatum (Diptera: Simuliidae).

The complete mitochondrial genome of the European blackfly, Simulium variegatum Meigen, 1818 was sequenced using a combined Illumina and Sanger sequencing approach. Using the known sequence of Chironomus tepperi Skuse, 1889 (Chironomidae) homologous NGS reads were identified and assembled. The genome is 15,367 bp in length and includes 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes and a control region. Gene order resembles that of the ancestral dipteran gene arrangement. The base composition of the genome is A (37.6%), T (35.3%), C (15.8%) and G (11.3%). The control region between 12S rRNA and tRNAIle is composed of 362 bp with no obvious repetitive motifs.

A new case of zoonotic onchocercosis in northern Kyushu, Japan.

A case of zoonotic onchocercosis has been found in a resident who lived in Iizuka City, Fukuoka Prefecture, Japan for some time. A 24-year-old male developed a painful nodule on the middle finger of his right hand. The nodule was surgically removed from the vagina fibrosa tendinis of the finger at Beppu Medical Center, Beppu City, Oita Prefecture in 2012. The causative agent was identified as a female Onchocerca dewittei japonica based on its histopathological characteristics. The identity of the filarioid has been confirmed by sequencing the cox1 gene. The present study indicates that the zoonotic onchocercosis caused by O. dewittei japonica has been concentrated in northeast Kyushu.