Mosquitoes of the Maculipennis complex in Northern Italy

AbstractThe correct identification of mosquito vectors is often hampered by the presence of morphologically indiscernible sibling species. The Maculipennis complex is one of these groups that include both malaria vectors of primary importance and species of low/negligible epidemiological relevance, of which distribution data in Italy are outdated. Our study was aimed at providing an updated distribution of Maculipennis complex in Northern Italy through the sampling and morphological/molecular identification of specimens from five regions. The most abundant species was Anopheles messeae (2032), followed by Anopheles maculipennis s.s. (418), Anopheles atroparvus (28) and Anopheles melanoon (13). Taking advantage of ITS2 barcoding, we were able to finely characterize tested mosquitoes, classifying all the Anopheles messeae specimens as Anopheles daciae, a taxon with debated rank to which we referred as species inquirenda (sp. inq.). The distribution of species was characterized by Ecological Niche Models (ENMs), fed by recorded points of presence. ENMs provided clues on the ecological preferences of the detected species, with An. daciae sp. inq. linked to stable breeding sites and An. maculipennis s.s. more associated to ephemeral breeding sites. We demonstrate that historical Anopheles malaria vectors are still present in Northern Italy.

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Mosquitoes of the Maculipennis complex in Northern Italy

10.1101/2020.11.02.365262 ◽

2020 ◽

Author(s):

Mattia Calzolari ◽

Rosanna Desiato ◽

Alessandro Albieri ◽

Veronica Bellavia ◽

Michela Bertola ◽

...

Keyword(s):

Abundant Species ◽

Northern Italy ◽

Malaria Vectors ◽

Distribution Data ◽

Correct Identification ◽

Ecological Niche Models ◽

Breeding Sites ◽

Anopheles Atroparvus ◽

Anopheles Maculipennis ◽

Maculipennis Complex

AbstractThe correct identification of mosquito vectors is often hampered by the presence of morphologically indiscernible sibling species. The Maculipennis complex is one of these groups which include both malaria vectors of primary importance and species of low/negligible epidemiological relevance, of which distribution data in Italy are outdated. Our study was aimed at providing an updated distribution of Maculipennis complex in Northern Italy through the sampling and morphological/molecular identification of specimens from five regions. The most abundant species was Anopheles messeae s.l. (2032), followed by Anopheles maculipennis s.s. (418), Anopheles atroparvus (28) and Anopheles melanoon (13). The distribution of species was characterized by Ecological Niche Models (ENMs), fed by recorded points of presence. ENMs provided clues on the ecological preferences of the detected species, with An. messeae s.l. linked to stable breeding sites and An. maculipennis s.s. more associated to ephemeral breeding sites. We demonstrate that historical Anopheles malaria vectors are still widespread in Northern Italy.

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Development of a chimeric odour blend for attracting gravid malaria vectors

Malaria Journal ◽

10.1186/s12936-021-03797-w ◽

2021 ◽

Vol 20 (1) ◽

Author(s):

Betelehem Wondwosen ◽

Mengistu Dawit ◽

Yared Debebe ◽

Habte Tekie ◽

Sharon R. Hill ◽

...

Keyword(s):

Vector Control ◽

Binary Logistic Regression ◽

Ground Level ◽

Malaria Vectors ◽

Volatile Components ◽

Innovative Strategy ◽

Breeding Sites ◽

Logistic Regression Models ◽

Plant Feeding ◽

Global Vector

Abstract Background Odour-based tools targeting gravid malaria vectors may complement existing intervention strategies. Anopheles arabiensis are attracted to, and stimulated to oviposit by, natural and synthetic odours of wild and domesticated grasses associated with mosquito breeding sites. While such synthetic odour lures may be used for vector control, these may have limited efficacy when placed in direct competition with the natural source. In this study, workflows developed for plant-feeding pests was used to design and evaluate a chimeric odour blend based on shared attractive compounds found in domesticated grass odours. Methods Variants of a synthetic odour blend, composed of shared bioactive compounds previously identified in domesticated grasses, was evaluated sequentially in a two-choice olfactometer to identify a ratio-optimized attractive blend for malaria vectors. During this process, blends with ratios that were significantly more attractive than the previously identified synthetic rice blend were compared to determine which was most attractive in the two-choice olfactometer. To determine whether all volatile components of the most attractive blend were necessary for maximal attraction, subtractive assays were then conducted, in which individual components were removed for the most attractive blend, to define the final composition of the chimeric blend. Binary logistic regression models were used to determine significance in all two-choice assays. The chimeric blend was then assessed under field conditions in malaria endemic villages in Ethiopia, to assess the effect of dose, trap type, and placement relative to ground level. Field data were analyzed both descriptively and using a Welch-corrected t-test. Results A ratio-optimized chimeric blend was identified that significantly attracted gravid An. arabiensis under laboratory conditions. In the field, trap captures of An. arabiensis and Anopheles pharoensis were dependent on the presence of the lure, trap type (CDC, BG Sentinel and Suna traps), placement relevant to ground level, with low release rates generally luring more mosquitoes. Conclusions The workflow designed for the development of chimeric lures provides an innovative strategy to target odour-mediated behaviours. The chimeric lure identified here can be used in existing trapping systems, and be customized to increase sustainability, in line with goals of the Global Vector Control Response Group.

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Entomological Surveillance in Former Malaria-endemic Areas of Southern Italy

Pathogens ◽

10.3390/pathogens10111521 ◽

2021 ◽

Vol 10 (11) ◽

pp. 1521

Author(s):

Donato Antonio Raele ◽

Francesco Severini ◽

Daniela Boccolini ◽

Michela Menegon ◽

Luciano Toma ◽

...

Keyword(s):

Malaria Vectors ◽

Public Health Issue ◽

Entomological Surveillance ◽

Widespread Species ◽

Animal Shelters ◽

Breeding Sites ◽

Artificial Breeding ◽

Anopheles Vectors ◽

Gargano Promontory ◽

Anopheles Algeriensis

Malaria still represents a potential public health issue in Italy, and the presence of former Anopheles vectors and cases imported annually merit continuous surveillance. In areas no longer endemic, the concurrent presence of gametocyte carriers and competent vectors makes re-emergence of local transmission possible, as recently reported in Greece. In October 2017, due to the occurrence of four suspected introduced malaria cases in the province of Taranto (Apulia region), entomological investigations were performed to verify the involvement of local anopheline species. In 2019–2020 entomological surveys were extended to other areas historically prone to malaria between the provinces of Taranto and Matera and the province of Foggia (Gargano Promontory). Resting mosquitoes were collected in animal shelters and human dwellings, larvae were sampled in natural and artificial breeding sites, and specimens were both morphologically and molecularly identified. A total of 2228 mosquitoes were collected, 54.3% of which were anophelines. In all the investigated areas, Anopheles labranchiae was the most widespread species, while Anopheles algeriensis was predominant at the Gargano sites, and Anopheles superpictus and Anopheles plumbeus were recorded in the province of Matera. Our findings showed a potentially high receptivity in the surveyed areas, where the abundance of the two former malaria vectors, An. labranchiae and An. superpictus, is related to environmental and climatic parameters and to anthropic activities.

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Data-driven and interpretable machine-learning modeling to explore the fine-scale environmental determinants of malaria vectors biting rates in rural Burkina Faso

10.1101/2021.04.13.439583 ◽

2021 ◽

Author(s):

Paul Taconet ◽

Angélique Porciani ◽

Dieudonné Diloma Soma ◽

Karine Mouline ◽

Frédéric Simard ◽

...

Keyword(s):

Machine Learning ◽

High Resolution ◽

Burkina Faso ◽

Environmental Variables ◽

Data Driven ◽

Malaria Vectors ◽

Environmental Determinants ◽

Breeding Sites ◽

Landscape Variables ◽

Interpretable Machine Learning

AbstractBackgroundImproving the knowledge and understanding of the environmental determinants of malaria vectors abundances at fine spatiotemporal scales is essential to design locally tailored vector control intervention. This work aimed at exploring the environmental tenets of human-biting activity in the main malaria vectors (Anopheles gambiae s.s., Anopheles coluzzii and Anopheles funestus) in the health district of Diébougou, rural Burkina Faso.MethodsAnopheles human-biting activity was monitored in 27 villages during 15 months (in 2017-2018), and environmental variables (meteorological and landscape) were extracted from high resolution satellite imagery. A two-step data-driven modeling study was then carried-out. Correlation coefficients between the biting rates of each vector species and the environmental variables taken at various temporal lags and spatial distances from the biting events were first calculated. Then, multivariate machine-learning models were generated and interpreted to i) pinpoint primary and secondary environmental drivers of variation in the biting rates of each species and ii) identify complex associations between the environmental conditions and the biting rates.ResultsMeteorological and landscape variables were often significantly correlated with the vectors’ biting rates. Many nonlinear associations and thresholds were unveiled by the multivariate models, both for meteorological and landscape variables. From these results, several aspects of the bio-ecology of the main malaria vectors were precised or hypothesized for the Diébougou area, including breeding sites typologies, development and survival rates in relation to weather, flight ranges from breeding sites, dispersal related to landscape openness.ConclusionsUsing high resolution data in an interpretable machine-learning modeling framework proved to be an efficient way to enhance the knowledge of the complex links between the environment and the malaria vectors at a local scale. More broadly, the emerging field of interpretable machine-learning has significant potential to help improving our understanding of the complex processes leading to malaria transmission.

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Species diversity and insecticide resistance within the Anopheles hyrcanus group in Ubon Ratchathani Province, Thailand

Parasites & Vectors ◽

10.1186/s13071-020-04389-4 ◽

2020 ◽

Vol 13 (1) ◽

Author(s):

Anchana Sumarnrote ◽

Hans J. Overgaard ◽

Vincent Corbel ◽

Kanutcharee Thanispong ◽

Theeraphap Chareonviriyaphap ◽

...

Keyword(s):

Insecticide Resistance ◽

Control Strategies ◽

Resistance Mechanism ◽

Abundant Species ◽

Malaria Vectors ◽

Pcr Assay ◽

Insecticide Susceptibility ◽

Human Landing ◽

Early Peak

Abstract Background Members of the Anopheles hyrcanus group have been incriminated as important malaria vectors. This study aims to identify the species and explore the insecticide susceptibility profile within the Anopheles hyrcanus group in Ubon Ratchathani Province, northeastern Thailand where increasing numbers of malaria cases were reported in 2014. Methods Between 2013 and 2015, five rounds of mosquito collections were conducted using human landing and cattle bait techniques during both the rainy and dry seasons. Anopheles mosquitoes were morphologically identified and their insecticide susceptibility status was investigated. Synergist bioassays were carried out with An. hyrcanus (s.l.) due to their resistance to all insecticides. An ITS2-PCR assay was conducted to identify to species the Hyrcanus group specimens. Results Out of 10,361 Anopheles females collected, representing 18 taxa in 2 subgenera, 71.8% were morphologically identified as belonging to the Hyrcanus Group (subgenus Anopheles), followed by An. barbirostris group (7.9%), An. nivipes (6.5%), An. philippinensis (5.9%) and the other 14 Anopheles species. Specimens of the Hyrcanus Group were more prevalent during the rainy season and were found to be highly zoophilic. Anopheles hyrcanus (s.l.) was active throughout the night, with an early peak of activity between 18:00 h and 21:00 h. ITS2-PCR assay conducted on 603 DNA samples from specimens within the Hyrcanus Group showed the presence of five sisters species. Anopheles peditaeniatus was the most abundant species (90.5%, n = 546), followed by An. nitidus (4.5%, n = 27), An. nigerrimus (4.3%, n = 26), An. argyropus (0.5%, n = 3), and An. sinensis (0.2%, n = 1). All An. hyrcanus (s.l.) specimens that were found resistant to insecticides (deltamethrin 0.05%, permethrin 0.75% and DDT 4% and synergist tests) belonged to An. peditaeniatus. The degree of resistance in An. peditaeniatus to each of these three insecticides was approximately 50%. Addition of PBO (Piperonyl butoxide), but not DEF (S.S.S-tributyl phosphotritioate), seemed to restore susceptibility, indicating a potential role of oxidases as a detoxifying enzyme resistance mechanism. Conclusions A better understanding of mosquito diversity related to host preference, biting activity and insecticide resistance status will facilitate the implementation of locally adapted vector control strategies.

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Smicronyx species (Coleoptera: Curculionidae), economically important seed predators of witchweeds (Striga spp.) (Scrophulariaceae) in sub-Saharan Africa

Bulletin of Entomological Research ◽

10.1017/s0007485300036300 ◽

1997 ◽

Vol 87 (1) ◽

pp. 3-17 ◽

Cited By ~ 4

Author(s):

D. M. Anderson ◽

M. L. Cox

Keyword(s):

West Africa ◽

Abundant Species ◽

Biocontrol Agents ◽

Sub Saharan Africa ◽

Distribution Data ◽

Seed Predators ◽

Smicronyx Umbrinus ◽

Sub Saharan ◽

Smicronyx Guineanus

AbstractThe taxonomy of three species of Smicronyx that are potential biocontrol agents of witchweeds (Striga spp.) in West Africa is revised. The two most abundant species are identified as Smicronyx(Afrosmicronyx) umbrinus Hustache and S. (Smicronyx) guineanus Voss. A third species is described as Smicronyx (Afrosmicronyx) dorsomaculatus Cox, sp. n. Diagnostic descriptions and a key, to separate adults of the three species from each other and from Sharpia bella Faust, are presented. Mature larvae of the three Smicronyx species are separated through a key and diagnoses. A lectotype is selected for Smicronyx umbrinus. All available host and distribution data are summarized for each species.

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Building multi‐layered resilience in a malaria control programme in Dar es Salaam, Tanzania

Progress in Development Studies ◽

10.1177/146499340901000404 ◽

2010 ◽

Vol 10 (4) ◽

pp. 309-324 ◽

Cited By ~ 8

Author(s):

Stefan Dongus ◽

Constanze Pfeiffer ◽

Emmy Metta ◽

Selemani Mbuyita ◽

Brigit Obrist

Keyword(s):

Malaria Control ◽

Breeding Site ◽

Control Programme ◽

Malaria Vectors ◽

Malaria Control Programme ◽

Social Resilience ◽

Breeding Sites ◽

Mosquito Breeding ◽

Field Workers ◽

Local Leaders

This study applied the multi‐layered social resilience framework in the context of an urban malaria control programme by using a qualitative approach. It was found that exchange between and within administrative levels supported resilience‐building processes in terms of mosquito breeding site elimination. ‘Reactive’ and ‘proactive’ capacities were successfully built among programme staff. However, more potential could be tapped among local leaders and household members, by increasing their competence in eliminating breeding sites of malaria vectors. Improving the communication skills of the programme’s field workers might support such processes. Together with local leaders, they could act as multipliers of sensitisation messages.

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Pollutants and insecticides drive local adaptation in African malaria mosquitoes

10.1101/067660 ◽

2016 ◽

Cited By ~ 1

Author(s):

Colince Kamdem ◽

Caroline Fouet ◽

Stephanie Gamez ◽

Bradley J. White

Keyword(s):

Anopheles Gambiae ◽

Local Adaptation ◽

Mosquito Species ◽

Sensu Stricto ◽

Detoxification Enzymes ◽

Malaria Vectors ◽

Breeding Sites ◽

Reduced Representation ◽

Malaria Epidemiology ◽

Rural And Urban

ABSTRACTThe Anopheles gambiae complex contains a number of highly anthropophilic mosquito species that have acquired exceptional ability to thrive in complex human habitats. Thus, examining the evolutionary history of this Afrotropical mosquito may yield vital information on the selective processes that occurred during the adaptation to human-dominated environments. We performed reduced representation sequencing on 941 mosquitoes of the Anopheles gambiae complex collected across four ecogeographic zones in Cameroon. We find evidence for genetic and geographic subdivision within An. coluzzii and An. gambiae sensu stricto – the two most significant malaria vectors in the region. Importantly, in both species, rural and urban populations are genetically differentiated. Genome scans reveal pervasive signatures of selection centered on genes involved in xenobiotic resistance. Notably, a selective sweep containing detoxification enzymes is prominent in urban mosquitoes that exploit polluted breeding sites. Overall, our study suggests that recent anthropogenic environmental modifications and widespread use of insecticides are driving population differentiation and local adaptation in vectors with potentially significant consequences for malaria epidemiology.

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Distribution and phylogenetic diversity of Anopheles species in malaria endemic areas of Honduras in an elimination setting

10.21203/rs.2.24779/v2 ◽

2020 ◽

Author(s):

Denis Escobar ◽

Krisnaya Ascencio ◽

Andrés Ortiz ◽

Adalid Palma ◽

Gustavo Fontecha

Keyword(s):

Genetic Diversity ◽

Phylogenetic Analyses ◽

Public Health Problem ◽

Abundant Species ◽

Malaria Vectors ◽

Morphological Identification ◽

High Genetic Diversity ◽

Homogeneous Population ◽

Molecular Approaches ◽

Endemic Areas

Abstract Background: Anopheles mosquitoes are the vectors of malaria, one of the most important infectious diseases in the tropics. More than 500 Anopheles species have been described worldwide, and more than 30 are considered a public health problem. In Honduras, information on the distribution of Anopheles spp. and its genetic diversity is scarce. This study aimed to describe the distribution and genetic diversity of Anopheles mosquitoes in Honduras. Methods: Mosquitoes were captured in 8 locations in 5 malaria endemic departments during 2019. Two collection methods were used. Adult anophelines were captured outdoors using CDC light traps and by aspiration of mosquitoes at rest. The morphological identification was performed using taxonomic keys. Genetic analyses included the sequencing of a partial region of the cytochrome oxidase I gene (COI) and the ribosomal internal transcribed spacer 2 (ITS2). Results: A total of 1320 anophelines were collected and identified through morphological keys. Seven Anopheles species were identified. Anopheles albimanus was the most widespread and abundant species (74.02%). To confirm the morphological identification of the specimens, 175 and 122 sequences were obtained for COI and ITS2 respectively. Both markers confirmed the morphological identification. COI showed a greater nucleotide diversity than ITS2 in all species. High genetic diversity was observed within the populations of An. albimanus while An. darlingi proved to be a highly homogeneous population. Phylogenetic analyses revealed clustering patterns in An. darlingi and An. neivai in relation to specimens from South America. New sequences for An. crucians, An. vestitipennis, and An. neivai are reported in this study.Conclusions: Here we report the distribution and genetic diversity of Anopheles species in endemic areas of malaria transmission in Honduras. According to our results, both taxonomic and molecular approaches are useful tools in the identification of anopheline mosquitoes. However, both molecular markers differ in their ability to detect intraspecific genetic diversity. These results provide supporting data for a better understanding of the distribution of malaria vectors in Honduras.

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Biology and morphology of the larva of Ecnomus tenellus (Rambur, 1842) (Trichoptera: Ecnomidae)

Zoosymposia ◽

10.11646/zoosymposia.5.1.6 ◽

2011 ◽

Vol 5 (1) ◽

pp. 71-82

Author(s):

CARLA CORALLINI ◽

MARIA CLARA BICCHIERAI

Keyword(s):

Southern Italy ◽

Central Italy ◽

Abundant Species ◽

Northern Italy ◽

Larval Morphology ◽

The Family ◽

River Po

Ecomus tenellus (Rambur) is the only species of the Family Ecnomidae found in Italy. In northern Italy it is only found along the river Po and its affluents. In Central Italy this species is more evenly distributed and in southern Italy it was found in few locations. Our study deals with the biology and the diet of the larva of E. tenellus. The specimens for this study were collected in Lake Trasimeno (Umbria, Italy) where E. tenellus is the most abundant species of Trichoptera. Larval morphology was investigated. Examination of the mouth parts showed that larvae can be shovel-predators.

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