Abundance, distribution, and dynamics of Anopheles species (Diptera: Culicidae) in Iowa, United States.

Malaria was once endemic in the United States prior to its elimination in 1951. However, due to consistent introductions of travel-associated malaria cases and the presence of several native Anopheles species (Diptera: Culicidae) that are competent vectors of malaria, the potential for local (autochthonous) malaria transmission remains a persistent threat in the United States. While several intermittent cases of local malaria transmission have occurred in the United States in the decades since elimination, the emergence of autochthonous transmission in 4 states in 2023 demonstrates the continued risk for future outbreaks. Moreover, these recent examples also highlight significant gaps in current mosquito surveillance efforts that have predominantly focused on threats of arboviral disease, such that our understanding of Anopheles distributions relies only on historical records and offers limited insight into the ecological factors that influence their abundance. Herein, we summarize mosquito surveillance data collected over the last 20 years (2004-2023) across 59 Iowa counties to provide essential information into the spatial distribution, temporal abundance, and trap preferences of Anopheles species in the state. Further analyses of the 2 most abundant species, Anopheles punctipennis Say and Anopheles quadrimaculatus Say, reveal the additional influence of precipitation and forested habitats in defining An. punctipennis abundance. Together, we believe these results provide an increased understanding of previously neglected Anopheles species that have the potential for autochthonous malaria transmission in Iowa and that can be extended to other regions of the United States to enhance preparedness for future malaria outbreaks.

The invasive Aedes albopictus in the Doñana World Heritage Site.

BACKGROUND: Aedes albopictus is catalogued as one of the 100 most dangerous species worldwide. Native to Asia, the species has drastically increased its distribution range, reaching all continents except Antarctica. The presence of Ae. albopictus in Spain was first reported in 2004 in Cataluña (NE Spain), and it is spreading in the country. METHODS: We conducted an extensive mosquito monitoring study in the natural protected area of the Doñana National Park (SW Spain) in 2023. After identifying the presence of Ae. albopictus, a mosquito control strategy was developed and implemented to eradicate the species in the area. RESULTS: Overall, 12,652 mosquito females of 14 different species were captured at nine sites within the park. For the first time, the presence of Ae. albopictus was recorded in the area, despite intensive trapping performed at some localities since 2003. The presence of this invasive species in the park is most likely linked to human activities, potentially facilitated by daily car trips of personnel. Although larvae of Culex, Anopheles, and Culiseta mosquitoes were identified in these containers, the presence of Ae. albopictus larvae was not recorded in those locations. In spite of that, the biological larvicide Bacillus thuringiensis israelensis (Bti) was applied to artificial containers potentially used by Ae. albopictus as breeding sites. CONCLUSIONS: This work evidences the high capacity of Ae. albopictus to reach highly conserved natural areas far from urban foci. We discuss the implications of the presence of Ae. albopictus in this endangered ecosystem and the potential control measures necessary to prevent its reintroduction.

Dirofilaria sp. and Blood Meal Analysis in Mosquitoes Collected in Vojvodina and Macva, and the First Report of Setaria tundra (Issaitshikoff & Rajewskaya, 1928) in Serbia.

Dirofilaria immitis and D. repens are the two most widespread and important species of mosquito-borne nematodes, posing a significant threat to veterinary health and particularly affecting canines and felines. While D. immitis causes cardiopulmonary dirofilariasis, D. repens causes subcutaneous infections in dogs and other carnivores. Despite the extensive knowledge on these parasites, little is known about their natural vectors in Serbia. The parasite Setaria tundra, known to infect deer, has not yet been detected in Serbia but has been documented in neighboring countries. Thus, the aim of this study was to (i) further map out Dirofilaria sp. hotspots in the Vojvodina Province and detect S. tundra for the first time, (ii) detect positive mosquito species that can provide insights into how the nematodes spread in Serbia, and (iii) analyze the blood-fed female mosquitoes of species found to be infected, in order to identify the potential source of parasite infection. A total of 2902 female mosquitoes were collected across 73 locations during 2021 and 2022. Molecular biology methods, based on conventional PCR, were used to analyze non-blood-fed (2521 specimens) and blood-fed (381 specimens) female mosquitos, in order to detect filarial nematode presence and identify blood-meal sources, respectively. When the parasite genome was detected, the amplicon (cox1 gene, 650 bp fragment) was sent for Sanger sequencing, further confirming the presence of nematodes and species assignation. D. immitis was detected in three Culex pipiens mosquitoes collected in Zrenjanin (August 2021) and Glogonj and Svetozar Miletic (both in July 2021). Additionally, Setaria tundra was detected in Aedes vexans collected in Idos (mid-August 2021) and Aedes caspius, which was collected in Mali Idos (end of July 2021). This work identifies two new locations where D. immitis occurs in Vojvodina, and is the first report of S. tundra in Serbian territory. Blood-meal analysis provided insights into the preferences of mosquitoes that were positive for Dirofilaria sp. and S. tundra.

Enhancing Eastern Equine Encephalitis Virus Surveillance in New Jersey: Optimized Collection of Culiseta melanura.

Eastern equine encephalitis virus (EEEV) causes the most clinically severe neuroinvasive arboviral disease in the United States. The virus is endemic in eastern and Gulf Coast states and the Great Lakes region, causing cases annually. To detect EEEV circulation in its enzootic cycle before the virus infects humans and other mammals, mosquito control agencies in New Jersey have conducted mosquito surveillance using a series of permanent wooden resting box sites since 1975. We conducted 2 field studies, 1 evaluating resting traps and 1 evaluating efficacy of CO2 lures, to optimize collection of Culiseta melanura, the primary enzootic vector of EEEV. Resulting mosquito samples were subjected to molecular analysis to determine EEEV infection rates. Corrugated plastic boxes trapped more bloodfed Cs. melanura than other resting trap types (resting boxes, Centers for Disease Control and Prevention [CDC] resting traps, or fiber pots) and were similar to resting boxes in total number of female Cs. melanura caught. Further, non-baited CDC light traps were more successful in trapping host-seeking Cs. melanura than those baited with dry ice, a CO2 lure. The EEEV RNA was identified in Cs. melanura, Aedes vexans, Anopheles quadrimaculatus, and Uranotaenia sapphirina. Our findings indicate that corrugated plastic boxes and non-CO2 baited traps could improve detection of Cs. melanura. Mosquito control agencies are encouraged to periodically assess their surveillance strategy for EEEV.

Multiplex PCR method for MinION sequencing of Bagaza virus isolated from wild caught mosquitoes in South Africa.

Bagaza virus (BAGV) is a mosquito-borne orthoflavivirus known to occur in regions of southern Europe, Africa, India and the Middle East. The virus has been associated with neurological disease and fatalities in various wild bird species. Association with human disease is not confirmed although limited serological evidence has suggested human infection. Surveillance programs for screening mosquitoes for evidence of arbovirus infection play an important role in providing information regarding the circulation and spread of viruses in specific regions. BAGV was detected in a mosquito pool during surveillance of mosquitoes collected in central South Africa between November 2019 and March 2023. Homogenized mosquito pools were screened for flaviviral RNA using conventional RT-PCR and virus isolation was attempted on positive samples. BAGV was detected and subsequently isolated using cell culture. A multiplex tiling PCR method for targeted enrichment using a PCR based or amplicon sequencing approach of the complete genome of BAGV was developed and optimized. Primers were designed using alignment of complete genome sequence data retrieved from GenBank to identify suitable primer sites that would generate overlapping fragments spanning the complete genome. Six forward primers and eight reverse primers were identified that target the complete genome and amplified nine overlapping fragments, that ranged in length from 1954 to 2039 with an overlap ranging from 71 to 711 base pairs. The design strategy included multiple forward and reverse primer pairs for the 5' and 3' ends. Phylogenetic analysis with other isolates was performed and BAGV isolate VBD 74/23/3 was shown to share high similarity with previous BAGV isolates from all regions, with genetic distance ranging from 0.026 to 0.083. VBD 74/23/3 was most closely related to previous isolates from southern Africa, ZRU96/16/2 isolated from a post-mortem sample from a pheasant in 2016 and MP-314-NA-2018 isolated from mosquitoes in northwestern Namibia with genetic distance 0.0085 and 0.016 respectively. Currently there is limited complete genome sequence data available for many of the arboviruses circulating in Africa. The multiplex tiling method provided a simple and cost-effective method for obtaining complete genome sequence. This method can be readily applied to other viruses using sequence data from publicly available databases and would have important application facilitating genomic surveillance of arboviruses in low resource countries.

Characterizing the seasonal abundance and reproductive activity of overwintering Anopheles (Diptera: Culicidae) mosquitoes.

In temperate regions of the United States, female Anopheles mosquitoes respond to low temperatures and short photoperiods by entering an overwintering dormancy or diapause. Diapause in Anopheles results in reduced frequency of blood-feeding and reproductive arrest, indicating a period when pathogen transmission by these mosquitoes is unlikely. However, it is unclear precisely how late into the fall and how early in the spring these mosquitoes are biting, reproducing, and potentially transmitting pathogens. This is further complicated by the lack of clear markers of diapause in Anopheles (e.g., changes in egg follicle length). Our goal was to characterize the seasonal reproductive activity of female Anopheles in central Ohio, United States and evaluate egg follicle length as an indicator of Anopheles diapause. We used traditional mosquito traps and aspirators to collect Anopheles from urban woodlots and culverts, respectively, from late September 2021 through mid-May 2022 in central Ohio. By measuring their egg follicle length, reproductive status, and blood-feeding status, we found that egg follicle length is not a reliable indicator of Anopheles diapause. We also found that a small proportion of An. punctipennis (Say), An. perplexens (Ludlow), and An. quadrimaculatus (Say) continued to bite and reproduce into early November 2021 and that females of these species terminated reproductive dormancy and began biting by mid-March 2022. This period of reproductive activity extends beyond current mosquito surveillance and control in Ohio. Our findings suggest that within temperate regions of North America, Anopheles have the capacity to transmit pathogens throughout the spring, summer, and fall.

Automated differentiation of mixed populations of free-flying female mosquitoes under semi-field conditions.

Great advances in automated identification systems, or 'smart traps', that differentiate insect species have been made in recent years, yet demonstrations of field-ready devices under free-flight conditions remain rare. Here, we describe the results of mixed-species identification of female mosquitoes using an advanced optoacoustic smart trap design under free-flying conditions. Point-of-capture classification was assessed using mixed populations of congeneric (Aedes albopictus and Aedes aegypti) and non-congeneric (Ae. aegypti and Anopheles stephensi) container-inhabiting species of medical importance. Culex quinquefasciatus, also common in container habitats, was included as a third species in all assessments. At the aggregate level, mixed collections of non-congeneric species (Ae. aegypti, Cx. quinquefasciatus, and An. stephensi) could be classified at accuracies exceeding 90% (% error = 3.7-7.1%). Conversely, error rates increased when analysing individual replicates (mean % error = 48.6; 95% CI 8.1-68.6) representative of daily trap captures and at the aggregate level when Ae. albopictus was released in the presence of Ae. aegypti and Cx. quinquefasciatus (% error = 7.8-31.2%). These findings highlight the many challenges yet to be overcome but also the potential operational utility of optoacoustic surveillance in low diversity settings typical of urban environments.

Case report: Zika surveillance complemented with wastewater and mosquito testing.

BACKGROUND: In June 2023, a local cluster of 15 Zika cases was reported in a neighbourhood in Northeastern Singapore. The last significant local transmission of Zika virus (ZIKV) with more than 450 cases was in 2016-2017. To monitor the situation and mitigate further transmission, case, entomological and wastewater-based surveillance were carried out. METHODS: Primary healthcare practitioners and the community were alerted to encourage timely case identification. Surveillance was enhanced through testing of Aedes mosquitoes collected from the National Gravitrap surveillance system, and wastewater samples were collected from a network of autosamplers deployed at manholes across the country. FINDINGS: ZIKV RNA was detected in mosquito pools (3/43; 7%) and individual mosquitoes (3/82; 3.7%) captured, and in wastewater samples (13/503) collected from the vicinity of the cluster of cases. Respective samples collected from other sites across the country were negative. The peak detection of ZIKV RNA in mosquitoes and wastewater coincided temporally with the peak in the number of cases in the area (15-25 May 2023). INTERPRETATION: The restriction of ZIKV signals from wastewater and mosquitoes within the neighbourhood suggested limited ZIKV transmission. The subsequent waning of signals suggested effectiveness of control measures. We demonstrate the utility of wastewater-based surveillance of ZIKV, which complements existing case- and entomological-based surveillance. The non-intrusive approach is particularly useful to monitor diseases such as Zika, which generally causes silent or mild infections, but may cause severe outcomes such as congenital Zika syndrome. FUNDING: This study was funded by Singapore's Ministry of Finance and the National Environment Agency, Singapore.

Field evaluation of an automated mosquito surveillance system which classifies Aedes and Culex mosquitoes by genus and sex.

BACKGROUND: Mosquito-borne diseases are a major concern for public and veterinary health authorities, highlighting the importance of effective vector surveillance and control programs. Traditional surveillance methods are labor-intensive and do not provide high temporal resolution, which may hinder a full assessment of the risk of mosquito-borne pathogen transmission. Emerging technologies for automated remote mosquito monitoring have the potential to address these limitations; however, few studies have tested the performance of such systems in the field. METHODS: In the present work, an optical sensor coupled to the entrance of a standard mosquito suction trap was used to record 14,067 mosquito flights of Aedes and Culex genera at four temperature regimes in the laboratory, and the resulting dataset was used to train a machine learning (ML) model. The trap, sensor, and ML model, which form the core of an automated mosquito surveillance system, were tested in the field for two classification purposes: to discriminate Aedes and Culex mosquitoes from other insects that enter the trap and to classify the target mosquitoes by genus and sex. The field performance of the system was assessed using balanced accuracy and regression metrics by comparing the classifications made by the system with those made by the manual inspection of the trap. RESULTS: The field system discriminated the target mosquitoes (Aedes and Culex genera) with a balanced accuracy of 95.5% and classified the genus and sex of those mosquitoes with a balanced accuracy of 88.8%. An analysis of the daily and seasonal temporal dynamics of Aedes and Culex mosquito populations was also performed using the time-stamped classifications from the system. CONCLUSIONS: This study reports results for automated mosquito genus and sex classification using an optical sensor coupled to a mosquito trap in the field with highly balanced accuracy. The compatibility of the sensor with commercial mosquito traps enables the sensor to be integrated into conventional mosquito surveillance methods to provide accurate automatic monitoring with high temporal resolution of Aedes and Culex mosquitoes, two of the most concerning genera in terms of arbovirus transmission.

Interactive effects of climate, land use and soil type on Culex pipiens/torrentium abundance.

The incidence and risk of mosquito-borne disease outbreaks in Northwestern Europe has increased over the last few decades. Understanding the underlying environmental drivers of mosquito population dynamics helps to adequately assess mosquito-borne disease risk. While previous studies have focussed primarily on the effects of climatic conditions (i.e., temperature and precipitation) and/or local environmental conditions individually, it remains unclear how climatic conditions interact with local environmental factors such as land use and soil type, and how these subsequently affect mosquito abundance. Here, we set out to study the interactive effects of land use, soil type and climatic conditions on the abundance of Culex pipiens/torrentium, highly abundant vectors of West Nile virus and Usutu virus. Mosquitoes were sampled at 14 sites throughout the Netherlands. At each site, weekly mosquito collections were carried out between early July and mid-October 2020 and 2021. To assess the effect of the aforementioned environmental factors, we performed a series of generalized linear mixed models and non-parametric statistical tests. Our results show that mosquito abundance and species richness consistently differ among land use- and soil types, with peri-urban areas with peat/clay soils having the highest Cx. pipiens/torrentium abundance and sandy rural areas having the lowest. Furthermore, we observed differences in precipitation-mediated effects on Cx. pipiens/torrentium abundance between (peri-)urban and other land uses and soil types. In contrast, effects of temperature on Cx. pipiens/torrentium abundance remain similar between different land use and soil types. Our study highlights the importance of both land use and soil type in conjunction with climatic conditions for understanding mosquito abundances. Particularly in relation to rainfall events, land use and soil type has a marked effect on mosquito abundance. These findings underscore the importance of local environmental parameters for studies focusing on predicting or mitigating disease risk.

A synthetic lure for Anopheles gambiae (Diptera: Culicidae) based on the attractive plant Parthenium hysterophorus.

Sugar is the sole diet for male mosquitoes and a complementary meal for females. Searching for natural sources of sugar is mediated by semiochemicals. Floral nectars, extra floral nectaries, damaged tissues of plants and rotten fruits are the most common sources of sugar in nature. I provide laboratory evidence of the high attraction of Parthenium hysterophorus L., a weed that grows in tropical climates, to Anopheles gambiae Giles. This study has tried to identify the chemicals which might be involved in the chemical attraction of A. gambiae to this plant. Using quantitative GC-MS analysis, α-pinene, camphene, 1-octen-3-ol, ß-pinene, cis-ß-ocimene, bornyl acetate, α-caryophyllene, hexadecanoic acid, and α-linolenic acid were identified as the main constituents of P. hysterophorus volatiles. Successive olfactory assays helped a better understanding of the more attractive chemicals of P. hysterophorus to A. gambiae which was the basis for testing a possible synthetic blend. Olfactory experiments proved this synthetic blend to be as attractive as Parthenium intact plants for A. gambiae. A minimal blend, consisting of only α-pinene, camphene, and cis-ß-ocimene, was also produced and laboratory experiments indicated its relative attraction for A. gambiae. This blend can be tested in the attractive toxic sugar bait stations for sampling, surveillance, or control programs of mosquitoes in tropical Africa, where A. gambiae sensu stricto transfer malaria among residents.

Detection of Zika Virus in Aedes aegypti and Aedes albopictus Mosquitoes Collected in Urban Forest Fragments in the Brazilian Amazon.

Zika virus (ZIKV) is an RNA flavivirus (Flaviviridae family) endemic in tropical and subtropical regions that is transmitted to humans by Aedes (Stegomyia) species mosquitoes. The two main urban vectors of ZIKV are Aedes aegypti and Aedes albopictus, which can be found throughout Brazil. This study investigated ZIKV infection in mosquito species sampled from urban forest fragments in Manaus (Brazilian Amazon). A total of 905 non-engorged female Ae. aegypti (22 specimens) and Ae. albopictus (883 specimens) were collected using BG-Sentinel traps, entomological hand nets, and Prokopack aspirators during the rainy and dry seasons between 2018 and 2021. All pools were macerated and used to inoculate C6/36 culture cells. Overall, 3/20 (15%) Ae. aegypti and 5/241 (2%) Ae. albopictus pools screened using RT-qPCR were positive for ZIKV. No supernatants from Ae. aegypti were positive for ZIKV (0%), and 15 out of 241 (6.2%) Ae. albopictus pools were positive. In this study, we provide the first-ever evidence of Ae. albopictus naturally infected with ZIKV in the Amazon region.

COMPARING THE EFFICIENCY OF DIFFERENT CARBON DIOXIDE SOURCES IN COLLECTING MOSQUITO VECTOR SPECIES ON THE TEMPE CAMPUS OF ARIZONA STATE UNIVERSITY.

We compared the effectiveness of 4 different carbon dioxide (CO2) sources (sugar-fermented BG-CO2, sugar-fermented Fleischmann yeast, dry ice, and compressed gas cylinders) in attracting different mosquito species in 2 separate 4 × 4 Latin square trials. The CO2 generated by dry ice and the gas cylinders collected more Culex quinquefasciatus than the sugar-fermented BG-CO2 and Fleischmann yeasts during the 1st trial (16-h surveillance periods), but there was no significant difference in Aedes aegypti numbers. There were no significant differences between the different CO2 sources in collecting Cx. quinquefasciatus and Ae. aegypti mosquitoes in the 2nd trial (24-h surveillance periods). Catches for Culiseta inornata and Cx. tarsalis were too low in both experiments for formal statistical analysis. Data can be used to inform local mosquito surveillance programs, but the selection of a CO2 source will also depend on financial and logistical constraints.

Integrated Plan of Insecticide Resistance Surveillance in Mosquito Vectors in France.

Mosquito-borne diseases such as malaria, dengue, or chikungunya have been re-emerging all over the world, including in Europe. Managing resistance to public health pesticides in mosquitoes is essential and requires global, integrated, and coordinated actions and strong engagement of decision-makers, scientists, and public health operators. In this context, the present work aims at proposing an integrated plan of resistance surveillance in France and in the French Overseas territories in order to provide graduated and appropriate responses according to the situation. Briefly, the plan relies on periodic monitoring of insecticide resistance at the population level in predefined sites using adequate biological, molecular, and/or biochemical approaches and a stratification of the level of resistance risk at the scale of territory to adjust surveillance and vector control actions. The plan relies on the latest methods and indicators used for resistance monitoring as recommended by the World Health Organization in order to prevent or slow down its extension in space and time. The plan has been developed for France but can be easily adapted to other countries in order to provide a coordinated response to the growing problem of mosquito resistance in Europe.

What incentives encourage local communities to collect and upload mosquito sound data by using smartphones? A mixed methods study in Tanzania.

BACKGROUND: To detect and identify mosquitoes using their characteristic high-pitched sound, we have developed a smartphone application, known as the 'HumBug sensor', that records the acoustic signature of this sound, along with the time and location. This data is then sent remotely to a server where algorithms identify the species according to their distinctive acoustic signature. Whilst this system works well, a key question that remains is what mechanisms will lead to effective uptake and use of this mosquito survey tool? We addressed this question by working with local communities in rural Tanzania and providing three alternative incentives: money only, short message service (SMS) reminders and money, and SMS reminders only. We also had a control group with no incentive. METHODS: A multi-site, quantitative empirical study was conducted in four villages in Tanzania from April to August 2021. Consenting participants (n = 148) were recruited and placed into one of the three intervention arms: monetary incentives only; SMS reminders with monetary incentives; and SMS reminders only. There was also a control group (no intervention). To test effectiveness of the mechanisms, the number of audio uploads to the server of the four trial groups on their specific dates were compared. Qualitative focus group discussions and feedback surveys were also conducted to explore participants' perspectives on their participation in the study and to capture their experiences of using the HumBug sensor. RESULTS: Qualitative data analysis revealed that for many participants (37 out of 81), the main motivation expressed was to learn more about the types of mosquitoes present in their houses. Results from the quantitative empirical study indicate that the participants in the 'control' group switched on their HumBug sensors more over the 14-week period (8 out of 14 weeks) when compared to those belonging to the 'SMS reminders and monetary incentives' trial group. These findings are statistically significant (p < 0.05 or p > 0.95 under a two-sided z-test), revealing that the provision of monetary incentives and sending SMS reminders did not appear to encourage greater number of audio uploads when compared to the control. CONCLUSIONS: Knowledge on the presence of harmful mosquitoes was the strongest motive for local communities to collect and upload mosquito sound data via the HumBug sensor in rural Tanzania. This finding suggests that most efforts should be made to improve flow of real-time information back to the communities on types and risks associated with mosquitoes present in their houses.

Phylogenetic characterization of Orthobunyaviruses isolated from Trinidad shows evidence of natural reassortment.

The genus Orthobunyavirus is a diverse group of viruses in the family Peribunyaviridae, recently classified into 20 serogroups, and 103 virus species. Although most viruses within these serogroups are phylogenetically distinct, the absence of complete genome sequences has left several viruses incompletely characterized. Here we report the complete genome sequences for 11 orthobunyaviruses isolated from Trinidad, French Guiana, Guatemala, and Panama that were serologically classified into six serogroups and 10 species. Phylogenetic analyses of these 11 newly derived sequences indicate that viruses belonging to the Patois, Capim, Guama, and Group C serocomplexes all have a close genetic origin. We show that three of the 11 orthobunyaviruses characterized (belonging to the Group C and Bunyamwera serogroups) have evidence of histories of natural reassortment through the M genome segment. Our data also suggests that two distinct lineages of Group C viruses concurrently circulate in Trinidad and are transmitted by the same mosquito vectors. This study also highlights the importance of complementing serological identification with nucleotide sequencing when characterizing orthobunyaviruses.

Are You Still Using 6-Volt Batteries for Your Insect Traps?

The most prevalent insect sampling and surveillance problem is powering insect traps in the field. Most modern light traps use 6-V power supplies such as the Centers for Disease Control and Prevention (CDC) suction trap. Buck converter modules efficiently reduce 12-V direct current power to 6-V, which permits the use of higher voltage batteries with lower voltage traps, resulting in longer operational duration and reduced labor requirements associated with replacing and recharging batteries in the field. We evaluated several battery configurations of 6- and 12-V lead-acid batteries in various sizes (10-20 ampere-hours) and addressed, in the circuit design, common problems that occur when using the buck converter (such as crossing polarity and excessive battery depletion). The efficacy of each configuration was assessed by measuring the voltage and suction while powering a 6-V CDC light trap. The buck converter permitted the use of cheaper and more commonly available 12-V batteries to run the CDC light traps and resulted in longer effective operation time as measured by air speed.

An updated checklist of mosquitoes (Diptera: Culicidae) from Chandigarh, India and its surrounding area.

Background & objectives: The affirmation about the prevalence of mosquito species at a particular place and time is very significant, not only to predict the danger of diseases or future outbreaks but also to control the vectors in time. Despite mosquitoes being medically important, the information about its faunal diversity is very scanty as far as Chandigarh in India and its nearby areas are concerned. So, this study was carried out to survey the mosquito fauna from areas in and around Chandigarh in northern India. Methods: Detailed mosquito surveys were carried out to explore the mosquito fauna from various habitats of developed urban areas, gardens, slums and surrounding villages of Chandigarh from June 2017-November 2019 using hand nets and oral aspirators. Results: A total of 34 mosquito species belonging to 8 genera viz; Anopheles, Aedes, Armigeres, Culex, Coquillet-tidia, Mansonia, Mimomyia and Verrallina were recorded, identified and preserved along with detailed collection data, of which eight are new records from Chandigarh. Interpretation & conclusion: The present checklist of mosquito fauna comprising 34 species provides information on the occurrence of mosquito vectors in Chandigarh and its adjoining areas which will be beneficial for the health authorities to adopt appropriate measures in time for the control of these vectors.

Filarial nematodes in domestic dogs and mosquitoes (Diptera: Culicidae) from semi-rural areas in Central Chile.

Climate change, competent vectors, and reservoir animals are the main factors for developing vector-borne zoonotic diseases. These diseases encompass a significant and widespread category of pathogens (e.g., viruses, bacteria, protozoa, and helminths) transmitted by blood-feeding arthropods, including ticks, fleas, lice, triatomines, mosquitoes, sandflies, and blackflies. In Chile, several studies have explored the role of dogs as reservoirs of vector-borne pathogens; however, there is a lack of research investigating the presence of pathogens in arthropods. Specifically, within the order Diptera, limited knowledge exists regarding their roles as carriers of pathogens. This study aimed to examine the presence of zoonotic filarial nematodes in mosquitoes and dogs within a previously unstudied semi-rural area of Central Chile. Two hundred samples of dog blood and seven hundred and twenty-four mosquitoes were collected during 2021-2022 and studied for filarial nematodes by PCR. The prevalence of microfilaremic dogs detected by Knott's test was 7.5%, with Acanthocheilonema reconditum being the only species identified. Aedes (Ochlerotatus) albifasciatus was the most abundant mosquito species collected, and 15 out of 65 pools were positive for filarial nematodes. Among these pools, 13 tested positive for Acanthocheilonema reconditum, and two tested positive for Setaria equina through PCR. Additionally, five Culex pipiens specimens were positive for Acanthocheilonema reconditum. Despite the absence of zoonotic filarial species, these findings underscore the significance of monitoring pathogens in mosquitoes and animal hosts and continued research into the dynamics of vector-borne diseases, particularly in unexplored regions.

Entomological Surveillance of the Invasive Aedes Species at Higher-Priority Entry Points in Northern Iran: Exploratory Report on a Field Study.

BACKGROUND: Arboviral diseases such as dengue, Zika, and chikungunya are transmitted by Aedes aegypti and Ae albopictus and are emerging global public health concerns. OBJECTIVE: This study aimed to provide up-to-date data on the occurrence of the invasive Aedes species in a given area as this is essential for planning and implementing timely control strategies. METHODS: Entomological surveillance was planned and carried out monthly from May 2018 to December 2019 at higher-priority entry points in Guilan Province, Northern Iran, using ovitraps, larval collection, and human-baited traps. Species richness (R), Simpson (D), evenness (E), and Shannon-Wiener indexes (H̕) were measured to better understand the diversity of the Aedes species. The Spearman correlation coefficient and regression models were used for data analysis. RESULTS: We collected a total of 3964 mosquito samples including 17.20% (682/3964) belonging to the Aedes species, from 3 genera and 13 species, and morphologically identified them from May 2018 to December 2019. Ae vexans and Ae geniculatus, which showed a peak in activity levels and population in October (226/564, 40.07% and 26/103, 25.2%), were the eudominant species (D=75.7%; D=21.2%) with constant (C=100) and frequent (C=66.7%) distributions, respectively. The population of Ae vexans had a significant positive correlation with precipitation (r=0.521; P=.009) and relative humidity (r=0.510; P=.01), whereas it was inversely associated with temperature (r=-0.432; P=.04). The Shannon-Wiener Index was up to 0.84 and 1.04 in the city of Rasht and in July, respectively. The rarefaction curve showed sufficiency in sampling efforts by reaching the asymptotic line at all spatial and temporal scales, except in Rasht and in October. CONCLUSIONS: Although no specimens of the Ae aegypti and Ae albopictus species were collected, this surveillance provides a better understanding of the native Aedes species in the northern regions of Iran. These data will assist the health system in future arbovirus research, and in the implementation of effective vector control and prevention strategies, should Ae aegypti and Ae albopictus be found in the province.