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Insects May 2024Two species of black flies (Simuliidae) in Thailand, Takaoka and Kuvangkadilok, 2000, and Takaoka, Srisuka & Saeung, 2022, are potent vectors of avian blood protozoa...
Two species of black flies (Simuliidae) in Thailand, Takaoka and Kuvangkadilok, 2000, and Takaoka, Srisuka & Saeung, 2022, are potent vectors of avian blood protozoa of the genera and and are pests of domestic avian species. Although the adults are abundant throughout Thailand, information on their breeding habitats is limited, and the immature stages of are unknown. We collected the larvae and pupae of from the Mekong River, the first-ever record of Simuliidae from this large continental river. Mitochondrial cytochrome c oxidase I and internal transcribed spacer 2 were used to associate the larvae and pupae with known adults. Both genetic markers strongly supported their identity as . The larvae and pupa of are described. The pupal gill filaments, larval abdominal protuberances, and setae distinguish this species from other members of the species group. The immature stages of inhabit a wide variety of flowing waters, from small streams (3 m wide) to enormous continental rivers (400 m wide); thus, is a habitat generalist. In contrast, was found only in the large Mekong River and is, therefore, a habitat specialist. Both species can exploit their principal habitats and produce abundant adult populations.
PubMed: 38786902
DOI: 10.3390/insects15050346 -
Philosophical Transactions of the Royal... Apr 1999Human onchocerciasis (river blindness) is the filarial infection caused by Onchocerca volvulus and transmitted among people through the bites of the Simulium vector....
Human onchocerciasis (river blindness) is the filarial infection caused by Onchocerca volvulus and transmitted among people through the bites of the Simulium vector. Some 86 million people around the world are at risk of acquiring the nematode, with 18 million people infected and 600,000 visually impaired, half of them partially or totally blind. 99% of cases occur in tropical Africa; scattered foci exist in Latin America. Until recently control programmes, in operation since 1975, have consisted of antivectorial measures. With the introduction of ivermectin in 1988, safe and effective chemotherapy is now available. With the original Onchocerciasis Control Programme of West Africa coming to an end, both the new African Programme for Onchocerciasis Control and the Onchocerciasis Elimination Programme for the Americas, rely heavily on ivermectin self-sustained mass delivery. In consequence, the need for understanding the processes regulating parasite abundance in human and simuliid populations is of utmost importance. We present a simple mathematical framework built around recent analyses of exposure- and density-dependent processes operating, respectively, within the human and vector hosts. An expression for the basic reproductive ratio, R0, is derived and related to the minimum vector density required for parasite persistence in localities of West Africa in general and northern Cameroon in particular. Model outputs suggest that constraints acting against parasite establishment in both humans and vectors are necessary to reproduce field observations, but those in humans may not fully protect against reinfection. Analyses of host age-profiles of infection prevalence, intensity, and aggregation for increasing levels of endemicity and intensity of transmission in the Vina valley of northern Cameroon are in agreement with these results and discussed in light of novel work on onchocerciasis immunology.
Topics: Adolescent; Adult; Age Factors; Animals; Anthelmintics; Burkina Faso; Cameroon; Child; Child, Preschool; Cote d'Ivoire; Epidemiologic Methods; Female; Humans; Infant; Insect Vectors; Ivermectin; Life Cycle Stages; Male; Models, Biological; Models, Statistical; Onchocerca volvulus; Onchocerciasis; Onchocerciasis, Ocular; Population Dynamics; Prevalence; Simuliidae
PubMed: 10365406
DOI: 10.1098/rstb.1999.0433 -
Biomolecules Aug 2019A comparative study of melanin and ommochrome-containing samples, isolated from the black soldier fly (BSF) by enzymatic hydrolysis, alkaline and acid alcohol extraction...
A comparative study of melanin and ommochrome-containing samples, isolated from the black soldier fly (BSF) by enzymatic hydrolysis, alkaline and acid alcohol extraction or by acid hydrolysis, was carried out. Melanin was isolated both as a melanin-chitin complex and as a water-soluble melanin. Acid hydrolysis followed by delipidization yielded a more concentrated melanin sample, the electron spin resonance (ESR) signal of which was 2.6 × 10 spin/g. The ommochromes were extracted from the BSF eyes with acid methanol. The antiradical activity of BSF melanins and ommochromes was determined by the method of quenching of luminol chemiluminescence. It has been shown that delipidization of water-soluble melanin increases its antioxidant properties. A comparison of the antioxidant activity of BSF melanins and ommochromes in relation to photoinduced lipid peroxidation was carried out. The ESR characteristics of native and oxidized melanins and ommochromes were studied. It is assumed that adult flies can be a useful source of natural pigments with antioxidant properties.
Topics: Adsorption; Animals; Antioxidants; Electron Spin Resonance Spectroscopy; Hydrogen Peroxide; Light; Lipid Peroxidation; Melanins; Phenothiazines; Simuliidae
PubMed: 31450873
DOI: 10.3390/biom9090408 -
PloS One 2018Efforts to recycle organic wastes using black soldier fly (BSF) Hermetia illucens into high-nutrient biomass that constitutes a sustainable fat (biodiesel) and...
Efforts to recycle organic wastes using black soldier fly (BSF) Hermetia illucens into high-nutrient biomass that constitutes a sustainable fat (biodiesel) and high-quality protein ingredient in animal feeds have recently gained momentum worldwide. However, there is little information on the most suitable rearing conditions for growth, development and survivorship of these flies, which is a prerequisite for mass production technologies. We evaluated the physiological requirements for growth and reproduction of H. illucens on two diets [spent grains supplemented with brewers' yeast (D1) and un-supplemented (D2)]. Development rates at nine constant temperatures (10-42°C) were fitted to temperature-dependent linear and non-linear day-degree models. Thereafter, life history table parameters were determined within a range of favourable temperatures. The thermal maximum (TM) estimates for larval, pre-pupal and pupal development using non-linear model ranged between 37.2 ± 0.3 and 44.0 ± 2.3°C. The non-linear and linear day-degree model estimations of lower developmental temperature threshold for larvae were 11.7 ± 0.9 and 12.3 ± 1.4°C for D1, and 10.4 ± 1.7 and 11.7 ± 3.0°C for D2, respectively. The estimated thermal constant of immature life stages development of BSF was higher for the larval stage (250±25 DD for D1 and 333±51 for D2) than the other stages evaluated. Final larval wet weight was higher on D1 compared to D2. The population growth rate was most favourable at 30-degree celsius (°C) with higher intrinsic rate of natural increase (rm = 0.127 for D1 and 0.122 for D2) and shorter doubling time (5.5 days for D1 and 5.7 days for D2) compared to the other temperatures. These results are valuable for the optimization of commercial mass rearing procedures of BSF under various environmental conditions and prediction of population dynamics patterns using computer simulation models.
Topics: Animal Feed; Animals; Biofuels; Biomass; Humans; Larva; Pupa; Reproduction; Simuliidae; Solid Waste; Temperature
PubMed: 30383771
DOI: 10.1371/journal.pone.0206097 -
Infectious Diseases of Poverty Aug 2019There is accumulating evidence supporting the use of ivermectin as a malaria control tool. Recent findings from the repeat ivermectin mass drug administrations for...
BACKGROUND
There is accumulating evidence supporting the use of ivermectin as a malaria control tool. Recent findings from the repeat ivermectin mass drug administrations for control of malaria trial demonstrated a reduced incidence of malaria in villages which received repeated ivermectin mass drug administration (MDA; six doses) compared to those who had only one round of ivermectin. Several other studies investigating the benefits of ivermectin for malaria purposes are ongoing/planned.
MAIN TEXT
While ivermectin MDA offers promising perspectives in the fight against malaria, we highlight the added benefits and anticipated challenges of conducting future studies in onchocerciasis-endemic regions, which are confronted with a substantial disease burden including onchocerciasis-associated epilepsy. Increasing the frequency of ivermectin MDA in such places may reduce the burden of both malaria and onchocerciasis, and allow for more entomological investigations on both the Anopheles mosquitoes and the blackflies. Upfront, acceptability and feasibility studies are needed to assess the endorsement by the local populations, as well as the programmatic feasibility of implementing ivermectin MDA several times a year.
CONCLUSIONS
Onchocerciasis-endemic sites would doubly benefit from ivermectin MDA interventions, as these will alleviate onchocerciasis-associated morbidity and mortality, while potentially curbing malaria transmission. Involving onchocerciasis programs and other relevant stakeholders in the malaria/ivermectin research agenda would foster the implementation of pluri-annual MDA in target communities.
Topics: Animals; Anopheles; Humans; Ivermectin; Malaria; Mass Drug Administration; Onchocerciasis; Simuliidae
PubMed: 31439040
DOI: 10.1186/s40249-019-0588-7 -
Parasites & Vectors Jun 2020The behaviour of blood-sucking arthropods is a crucial determinant of blood protozoan distribution and hence of host-parasite coevolution, but it is very challenging to...
BACKGROUND
The behaviour of blood-sucking arthropods is a crucial determinant of blood protozoan distribution and hence of host-parasite coevolution, but it is very challenging to study in the wild. The molecular identification of parasite lineages in vectors can be a useful key to understand the behaviour and transmission patterns realised by these vectors.
METHODS
In this study, we collected blackflies around nests of three raptor species in the upper forest canopy in central Europe and examined the presence of vertebrate DNA and haemosporidian parasites in them. We molecularly analysed 156 blackfly individuals, their vertebrate blood meals, and the haemosporidian parasite lineages they carried.
RESULTS
We identified nine species of Simulium blackflies, largely belonging to the subgenera Nevermannia and Eusimulium. Only 1% of the collected specimens was visibly engorged, and only 4% contained remains of host DNA. However, in 29% of the blackflies Leucocytozoon lineages were identified, which is evidence of a previous blood meal on an avian host. Based on the known vertebrate hosts of the recorded Leucocytozoon lineages, we can infer that large and/or abundant birds, such as thrushes, crows, pigeons, birds of prey, owls and tits are the main targets of ornithophilic blackflies in the canopy. Blackfly species contained similar proportions of host group-specific parasite lineages and thus do not appear to be associated with particular host groups.
CONCLUSIONS
The Leucocytozoon clade infecting thrushes, crows, and pigeons present in most represented blackfly species suggests a lack of association between hosts and blackflies, which can increase the probability of host switches of blood parasites. However, the composition of the simuliid species differed between nests of common buzzards, goshawks and red kites. This segregation can be explained by coinciding habitat preferences between host and vector, and may lead to the fast speciation of Leucocytozoon parasites. Thus, subtle ecological preferences and lack of host preference of vectors in the canopy may enable both parasite diversification and host switches, and enforce a habitat-dependent evolution of avian malaria parasites and related haemosporidia.
Topics: Animals; Bird Diseases; Blood; DNA; Female; Forests; Haemosporida; Host Specificity; Insect Vectors; Meals; Phylogeny; Raptors; Simuliidae
PubMed: 32539849
DOI: 10.1186/s13071-020-04177-0 -
Journal of Proteome Research Mar 2009Adaptation to vertebrate blood feeding includes development of a salivary "magic potion" that can disarm host hemostasis and inflammatory reactions. Within the lower...
Adaptation to vertebrate blood feeding includes development of a salivary "magic potion" that can disarm host hemostasis and inflammatory reactions. Within the lower Diptera, a vertebrate blood-sucking mode evolved in the Psychodidae (sand flies), Culicidae (mosquitoes), Ceratopogonidae (biting midges), Simuliidae (black flies), and the frog-feeding Corethrellidae. Sialotranscriptome analyses from several species of mosquitoes and sand flies and from one biting midge indicate divergence in the evolution of the blood-sucking salivary potion, manifested in the finding of many unique proteins within each insect family, and even genus. Gene duplication and divergence events are highly prevalent, possibly driven by vertebrate host immune pressure. Within this framework, we describe the sialome (from Greek sialo, saliva) of the black fly Simulium vittatum and discuss the findings within the context of the protein families found in other blood-sucking Diptera. Sequences and results of Blast searches against several protein family databases are given in Supplemental Tables S1 and S2, which can be obtained from http://exon.niaid.nih.gov/transcriptome/S_vittatum/T1/SV-tb1.zip and http://exon.niaid.nih.gov/transcriptome/S_vittatum/T2/SV-tb2.zip .
Topics: Amino Acid Sequence; Animals; Electrophoresis, Polyacrylamide Gel; Gene Library; Molecular Sequence Data; Phylogeny; Proteome; Saliva; Salivary Glands; Simuliidae; Tandem Mass Spectrometry
PubMed: 19166301
DOI: 10.1021/pr8008429 -
Journal of the American Mosquito... Dec 2018The diversity of nonculicid biting flies was surveyed in Sunset Zoo, Manhattan, KS, by carbon dioxide-baited traps. A total of 8,399 nonculicid biting-fly females...
The diversity of nonculicid biting flies was surveyed in Sunset Zoo, Manhattan, KS, by carbon dioxide-baited traps. A total of 8,399 nonculicid biting-fly females representing 32 species and 5 families were collected. Twenty-one biting midge (Ceratopogonidae: ) and 7 black fly (Simuliidae) species were collected, including new state records of 3 and 1 simuliid. The species richness of and Simuliidae within the zoo represents 72.4% and 41.2%, respectively, of the fauna known to occur in Kansas. Trap type significantly influenced ( < 0.05) collections of the 5 species analyzed, and trapping period affected 3 species. The diversity and abundance of nonculicid biting flies in the zoo as related to animal health and wellness is discussed.
Topics: Animals; Biota; Ceratopogonidae; Environment; Kansas; Population Density; Simuliidae
PubMed: 31442142
DOI: 10.2987/18-6761.1 -
Parasites & Vectors Oct 2018Entomological surveillance for pathogens based on molecular screening of putative arthropod vectors such as blackflies (Diptera: Simuliidae) is becoming increasingly...
BACKGROUND
Entomological surveillance for pathogens based on molecular screening of putative arthropod vectors such as blackflies (Diptera: Simuliidae) is becoming increasingly important. Surveillance provides a means to understand host and geographical patterns of underestimated biodiversity among North American species of Onchocerca and a pathway to identify and track expanding emergence of the zoonotic Onchocerca lupi. Herein, we have screened two blackfly species, Simulium tescorum and Simulium vittatum (s.l.), from Los Angeles County, southern California, USA for DNA of filarioid nematodes to better understand species richness and limits within the genus Onchocerca.
METHODS
A total of 1056 and 378 female blackflies was collected using CO-baited mosquito traps from March to November of 2015 and 2016, respectively. All blackflies during 2015 were individually processed for DNA extraction and PCR targeting of the cytochrome c oxidase subunit 1 (cox1) of the mitochondrial DNA (mtDNA). Specimens of S. tescorum collected in 2016 were processed individually with heads and bodies extracted separately, whereas those of S. vittatum (s.l.) were processed in pooled samples with heads and bodies extracted separately. A subset of filarioid-positive samples from 2015 and all samples from 2016 were screened using a PCR targeting the NADH dehydrogenase subunit 5 (nad5) gene (mtDNA).
RESULTS
In 2015, 356 S. tescorum (33.7%) and 683 S. vittatum (s.l.) (64.7%) were collected, and an additional 17 specimens were not assessed morphologically. In 2016, a total of 378 blackflies was collected. Of these, 43 (11.6%) were S. tescorum and 327 (88.4%) were S. vittatum (s.l.), and an additional 8 specimens were not assessed morphologically. In 2015, Onchocerca sequences were detected in 4.8% (n = 17) of S. tescorum samples, and only one S. vittatum (0.15%). In 2016, only a single S. vittatum pool was positive for the same cryptic Onchocerca species. In phylogenetic comparisons based on nad5, the Onchocerca sequences from California formed a clade with those isolates in white-tailed deer from upstate New York, suggesting these belong to a single widespread cryptic species.
CONCLUSIONS
An uncharacterized species of Onchocerca associated with cervid hosts was found in blackflies from southern California. Sequence data demonstrated it is likely conspecific with an unnamed species of Onchocerca previously found in white-tailed deer from upstate New York. Current data support recognition of a broad geographical distribution across North America for an apparently cryptic species of Onchocerca that is discrete from O. cervipedis, considered to be a typical filarioid among cervids. Our data suggest that this cryptic species of Onchocerca may infect subspecies of white-tailed deer (Odocoileus virginianus), and mule and black-tailed deer (Odocoileus hemionus) at temporal latitudes. The blackflies Simulium tescorum and S. vittatum (s.l.) (presumably, S. tribulatum) are putative vectors. Discovery of a cryptic complex indicates that species diversity and putative associations for definitive hosts and vectors of Onchocerca species in North America must be reassessed.
Topics: Animals; Biodiversity; California; DNA, Mitochondrial; Deer; Disease Vectors; Electron Transport Complex IV; Female; Insect Vectors; NADH Dehydrogenase; Onchocerca; Onchocerciasis; Phylogeny; Polymerase Chain Reaction; Simuliidae
PubMed: 30326946
DOI: 10.1186/s13071-018-3133-9 -
Parasites & Vectors Oct 2021Despite high black fly densities in persisting onchocerciasis foci in Cameroon, no vector control has ever been carried out to complement Community-Directed Treatment...
Knowledge/perception and attitude/practices of populations of two first-line communities of the Centre Region of Cameroon regarding onchocerciasis and black fly nuisance and bio-ecology.
BACKGROUND
Despite high black fly densities in persisting onchocerciasis foci in Cameroon, no vector control has ever been carried out to complement Community-Directed Treatment with Ivermectin (CDTI). As a prelude to community-based vector control, this study explored knowledge/perception and attitude/practice (KAP) of populations of two first-line communities regarding onchocerciasis, black fly nuisance and bio-ecology.
METHODS
A cross-sectional survey was conducted in two communities of the Bafia Health District, following a household-based interview approach using a structured questionnaire. KAP scores were calculated and categorised as good or poor based on the number of correct or positive responses. Associations between KAP and socio-demographic parameters were explored using logistic regression models.
RESULTS
A total of 215 individuals aged 15-100 years were interviewed. Positive associations were observed between good knowledge/perception and age and the duration of residency in the community. Most respondents (91.6%) described having post-biting sequels (oedema, itching) and more than half (69.3%) admitted that black fly bites affect their productivity. Although 81.4% of the respondents stated that black fly densities are higher during the rainy season, only 10.7% of them knew that they breed in the river. Also, 59.5% of the interviewees stated that black flies bite not only outdoors but also indoors, and 78.6% of enrolees were ready to help to fight against black flies. Most of the respondents were well aware of onchocerciasis, even though the transmission mode and vector bio-ecology were not well known.
CONCLUSION
This study revealed the need to implement community-based vector control to support CDTI in the fight against onchocerciasis and to reduce black fly nuisance.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Animals; Antiparasitic Agents; Cameroon; Cross-Sectional Studies; Endemic Diseases; Female; Health Knowledge, Attitudes, Practice; Humans; Ivermectin; Logistic Models; Male; Middle Aged; Onchocerciasis; Perception; Public Health; Seasons; Simuliidae; Surveys and Questionnaires; Young Adult
PubMed: 34688311
DOI: 10.1186/s13071-021-05048-y