Mosquito Production Research Articles

SEASONAL MOSQUITO PRODUCTION IN STORM SEWER CATCH BASINS OF THE NORTH SHORE SUBURBS OF CHICAGO, 2021 TO 2024.

From 2021 to 2024, the number of pupae found in storm sewer catch basins in the North Shore suburbs of Chicago were assessed as part of routine quality control and improvement efforts. Over the course of these 4 yr, pupae were collected at least once during all calendar months, allowing for some insight into monthly mosquito production in catch basins. Thus, the intent of this study was to use those data to describe the number of pupae found in these structures across calendar months. In total, 1,993 unique catch basins were sampled. Pupae were found during the months of April through December, with the highest levels seen during June through November. Results suggest that basins may remain productive a month or more after local abatement districts end their routine Culex adult surveillance with gravid traps in late September and early October each year. These observations can help with the timing and intensity of larvicide treatments in Chicago area catch basins and may serve as a baseline for comparison to future seasonal changes.

Long-term blood-free rearing of Anopheles mosquitoes with no effect on fitness, Plasmodium infectivity nor microbiota composition

Mosquito-borne diseases kill millions of people each year. Therefore, many innovative research and population control strategies are being implemented but, most of them require large-scale production of mosquitoes. Mosquito rearing depends on fresh blood from human donors, experimentation animals or slaughterhouses, which constitutes a strong drawback since high blood quantities are needed, raising ethical and financial constraints. To eliminate blood dependency and the use of experimentation animals, we previously developed BLOODless, a patented diet that represents an important advance towards sustainable mosquito breeding in captivity. BLOODless diet was used to maintain a colony of Anopheles stephensi for 40 generations. Bloodmeal appetite, fitness, Plasmodium berghei infectivity, whole genome sequencing and microbiota were evaluated over time. Here we show that BLOODless can be implemented in Anopheles insectaries since it allows long-term rearing of mosquitoes in captivity, without a detectable effect on their fitness, infectivity, nor on their midgut and salivary microbiota composition.

Upscaling the production of sterile male mosquitoes with an automated pupa sex sorter.

Effective mosquito population suppression has been repeatedly demonstrated in field trials through the release of male mosquitoes to induce sterile mating with wild females using the incompatible insect technique (IIT), the sterile insect technique (SIT), or their combination. However, upscaling these techniques requires a highly efficient and scalable approach for the sex separation of mass-reared mosquitoes to minimize the unintentional release of females, which can lead to either population replacement or biting nuisance, a major bottleneck up to now. Here, we report the successful development of an automated mosquito pupa sex sorter that can effectively separate large numbers of males from females for population suppression of Aedes aegypti, A. albopictus, and Culex quinquefasciatus. The male production capacity of the automated sex sorter was increased by ~17-fold compared with manual sex separation with the Fay-Morlan sorter and enabled one person to separate 16 million males per week. With ~0.5% female contamination, the produced males exhibited high flight ability and mating performance. The field trial demonstrates that the quality of A. albopictus males produced using the automated sex sorter is suitable for inducing population suppression. These results indicate that the automated sex sorter offers the potential to upscale IIT and SIT against mosquito vectors for disease control.

Effects of a blood-free mosquito diet on fitness and gonotrophic cycle parameters of laboratory reared Anopheles gambiae sensu stricto

BackgroundThe current rise of new innovative tools for mosquito control, such as the release of transgenic mosquitoes carrying a dominant lethal gene and Wolbachia-based strategies, necessitates a massive production of mosquitoes in the insectary. However, currently laboratory rearing depends on vertebrate blood for egg production and maintenance. This practice raises ethical concerns, incurs logistical and cost limitations, and entails potential risk associated with pathogen transmission and blood storage. Consequently, an artificial blood-free diet emerges as a desirable alternative to address these challenges. This study aims to evaluate the effects of a previously formulated artificial blood-free diet (herein referred to as BLOODless) on Anopheles gambiae (An. gambiae s.s.; IFAKARA) gonotrophic parameters and fitness compared with bovine blood.MethodsThe study was a laboratory-based comparative evaluation of the fitness, fecundity and fertility of An. gambiae s.s. (IFAKARA) reared on BLOODless versus vertebrate blood from founder generation (F0) to eighth generation (F8). A total of 1000 female mosquitoes were randomly selected from F0, of which 500 mosquitoes were fed with bovine blood (control group) and the other 500 mosquitoes were fed with BLOODless diet (experimental group). The feeding success, number of eggs per female, hatching rate and pupation rate were examined post-feeding. Longevity and wing length were determined as fitness parameters for adult male and female mosquitoes for both populations.ResultsWhile blood-fed and BLOODless-fed mosquitoes showed similar feeding success, 92.3% [95% confidence interval (CI) 89.7–94.9] versus 93.6% (95% CI 90.6–96.6), respectively, significant differences emerged in their reproductive parameters. The mean number of eggs laid per female was significantly higher for blood-fed mosquitoes (P < 0.001) whereas BLOODless-fed mosquitoes had significantly lower hatching rates [odds ratio (OR) 0.17, 95% CI 0.14–0.22, P < 0.001]. Wing length and longevity were similar between both groups.ConclusionsThis study demonstrates the potential of the BLOODless diet as a viable and ethical alternative to vertebrate blood feeding for rearing An. gambiae s.s. This breakthrough paves the way for more efficient and ethical studies aimed at combating malaria and other mosquito-borne diseases.Graphical

Entomopathogenic fungi Metarhizium pingshaense increases susceptibility to insecticides in highly resistant malaria mosquitoes Anopheles coluzzii

Background Metarhizium spp. based mosquito control products are among the most investigated and could potentially serve as promising complements to chemical insecticides. However, limited knowledge exists on the implementation of this biocontrol tool in conjunction with primary insecticide-based strategies to achieve synergy. Methods In laboratory bioassays, we combined 107 conidia/ml natives Metarhizium pingshaense strains with deltamethrin standard dose in three ways, before, after or simultaneously. These combinations were tested on laboratory insecticide resistant Anopheles coluzzii. Results Therefore, we found that Metarhizium pingshaense and deltamethrin could be combined to achieve greater mortality against a highly insecticide resistance colony of Anopheles coluzzii. When mosquitoes were exposed to both simultaneously, no effect was observed, as expected for an insecticide resistant colony. However, when fungi were applied earlier than deltamethrin, mosquitoes became more sensitive to insecticide with a minimum Lethal Time to kill at least 50% of mosquito population (LT50) less than 8 days. In addition, when deltamethrin exposure was followed by Metarhizium infection, mosquito survival was similar to Metarhizium alone LT50 (LT50 ~11 days). Conclusions These findings suggest that early mosquito infection to Metarhizium pingshaense followed by chemical insecticide exposure synergically improve mosquito control in the laboratory.

Influence of Air Pollution and Climate on Daily Health of Gabonese Students in the Capital (Libreville): A Pilot Study

Air pollution is a global issue affecting billions of people, especially urban populations in low- and middle-income countries. Since air pollution is a health problem that also involves the climate, this study assessed the relationship between the individual health of 50 college students living in Libreville (Gabon) and air quality, temperature, and humidity using low-cost equipment. The study utilised 81 days of data from the air pollution monitoring network in Libreville. These data were paired with measurements of heart rate, breathing, and stress measured using 5 Garmin vívosmart® smartwatches. In addition to the environmental and health data, participants were also asked about their state of health and their lifestyle during the study. We found average concentrations of PM2.5 (25.25 µg/m3) and PM10 (29.50 µg/m3) that exceed the 24-h WHO air quality standards. The daily average of PM1 was around 17.84 µg/m3. Temperatures observed during the study period varied between 27 and 35 °C (mean = 30.15 °C), and humidity was around 51-77% (mean = 59.5%). Overall, the relationships between the environmental conditions and the health observations were negligible, with correlation coefficients R ≤ 0.36. Despite their weakness, coefficients between 0.31 and 0.36 showed that stress levels are associated with temperature, PM2.5 and PM10. The average stress level was associated with PM10 (R = 0.34) and PM2.5 (R = 0.36). Finally, the study reveals that smokers, mosquito repellent users, and fan users have reduced breathing capacities compared to non-smokers, non-users of mosquito repellent products, non-users of fans, users and non-users of air conditioning. The study recommends the use of portable sensors to measure individual exposure to environmental parameters for similar studies, which will resolve the problem of spatial representativeness highlighted in this study. It is also recommended that Gabon's health policies incorporate early warnings of forecast high temperatures or pollution peaks, in order to limit health risks

D-Tetramethrin causes zebrafish hepatotoxicity by inducing oxidative stress and inhibiting cell proliferation

d-Tetramethrin is one of the main components of mosquito control products, and is widely used for the control of dengue fever and insecticide production. Due to its widespread use, d-tetramethrin is a ubiquitous environmental pollutant and poses potential risks to human health. However, the effects of d-tetramethrin on liver morphology and function are not clearly established. In this study, we used zebrafish as an animal model to analyze the acute and chronic effects of d-tetramethrin exposure on the liver. We exposed zebrafish larvae and adults to different concentrations of d-tetramethrin and examined the impact of d-tetramethrin on lipid and glycogen metabolism, cellular properties, oxidative stress, cell proliferation, and apoptosis in the liver. We also analyzed transcriptional changes in genes related to apoptosis, inflammation, and cell proliferation using qPCR. Zebrafish exposed to d-tetramethrin exhibited severe liver damage, as evidenced by the presence of vacuoles and nuclear distortion in liver cells. The liver area in zebrafish larvae of the treatment group was significantly smaller than that of the control group. Significant lipid accumulation and decreased glycogen levels were observed in the livers of both zebrafish larvae and adults exposed to d-tetramethrin. Furthermore, d-tetramethrin exposure induced apoptosis and inflammation in zebrafish embryos. Additionally, d-tetramethrin caused liver damage, metabolic dysfunction, and impaired liver function. These results suggest that d-tetramethrin induces liver toxicity in zebrafish, by inducing oxidative stress and inhibiting cell proliferation.

Comparison of yeast microencapsulated fluralaner to commercially available mosquito larval control products, 2023

Comparison of yeast microencapsulated fluralaner to commercially available mosquito larval control products, 2023

Are Adult Mosquito Control Products (Adulticides) Harmful? A Review of the Potential Human Health Impacts from Exposure to Naled and Dichlorvos (DDVP)

We performed a thorough systematic review of published literature to determine potential links between human health impacts and naled, a registered adult mosquito control product (adulticide), and its major degradate, dichlorvos (DDVP). A search query was performed on 8 September 2023, capturing all articles published up to that date on the Scopus and PubMed databases. Inclusion criteria were the presence of either pesticide and a measured or modeled human health outcome or risk. The search string resulted in 382 articles; however, 354 articles were excluded, resulting in only 28 articles that met the inclusion criteria. The studies that directly relate to aerosolized ultra-low volume (ULV) mosquito control applications did not report any associated deleterious human health outcomes. Results from the reviewed papers displayed no negative health effects or led to inconclusive results. No studies showed adverse health effects from aerial ULV applications for mosquito management. Our findings are congruent with the United States Environmental Protection Agency and Centers for Disease Control and Prevention recommendations that aerial applications of naled, following label parameters, do not pose an adverse risk exposure to humans, wildlife, and the environment.

Mosquito control exposures and breast cancer risk: analysis of 1071 cases and 2096 controls from the Ghana Breast Health Study

Epidemiologic data on insecticide exposures and breast cancer risk are inconclusive and mostly from high-income countries. Using data from 1071 invasive pathologically confirmed breast cancer cases and 2096 controls from the Ghana Breast Health Study conducted from 2013 to 2015, we investigated associations with mosquito control products to reduce the spread of mosquito-borne diseases, such as malaria. These mosquito control products were insecticide-treated nets, mosquito coils, repellent room sprays, and skin creams for personal protection against mosquitos. Multivariable and polytomous logistic regression models were used to estimate odds ratios (ORadj) and 95% confidence intervals (CI) with breast cancer risk-adjusted for potential confounders and known risk factors. Among controls, the reported use of mosquito control products were mosquito coils (65%), followed by insecticide-treated nets (56%), repellent room sprays (53%), and repellent skin creams (15%). Compared to a referent group of participants unexposed to mosquito control products, there was no significant association between breast cancer risk and mosquito coils. There was an association in breast cancer risk with reported use of insecticide-treated nets; however, that association was weak and not statistically significant. Participants who reported using repellent sprays were at elevated risks compared to women who did not use any mosquito control products, even after adjustment for all other mosquito control products (OR = 1.42, 95% CI=1.15–1.75). We had limited power to detect an association with repellent skin creams. Although only a few participants reported using repellent room sprays weekly/daily or < month-monthly, no trends were evident with increased frequency of use of repellent sprays, and there was no statistical evidence of heterogeneity by estrogen receptor (ER) status (p-het > 0.25). Our analysis was limited when determining if an association existed with repellent skin creams; therefore, we cannot conclude an association. We found limited evidence of risk associations with widely used mosquito coils and insecticide-treated nets, which are reassuring given their importance for malaria prevention. Our findings regarding specific breast cancer risk associations, specifically those observed between repellent sprays, require further study.

Rice farmers’ knowledge, attitudes and practices towards mosquitoes in irrigation schemes in Côte d’Ivoire: a qualitative study

BackgroundIrrigated rice cultivation in sub-Saharan Africa not only brings more malaria vectors to nearby communities, but also greater malaria risk. To aid the implementation of mosquito control in rice-growing communities, it is necessary to understand how farmers understand, view and manage their responsibility in mosquito generation and whether they are interested in coordinating to minimize it.MethodsQualitative methods (observation grids, semi-structured in-depth interviews and focus group discussions) were used to reveal the perceptions of mosquitoes and their control in two irrigated rice farming communities in central Côte d’Ivoire near the M’bé and Lokapli irrigation schemes.ResultsAll rice farmers viewed mosquitoes as severe nuisances, and most acknowledged that they caused djèkouadjo (malaria) and were less numerous during harmattan (dry season). Many study participants believed that mosquitoes originated from grasses and stagnant water around villages. Only those living closer in proximity (~ 1 km) to the paddies believed that mosquitoes came from the bas-fonds (irrigated lowlands). However, they did not associate mosquito production with rice cultivation. Some farmers believed that there were more mosquitoes in recent years than historically because of the dam construction, but remarked on the importance of the dam (and bas-fonds) for their livelihood. Many farmers were not convinced that mosquito control could occur at farm-level.ConclusionsTo enhance accountability amongst rice farmers, there is a need for greater awareness on the rice-mosquito link, and emphasis that the link does not imply a trade-off between food production and health. Training should not only be directed towards farming communities, but also agricultural and health extension workers. Future riceland mosquito control methods must focus on improving crop productivity and address collective action problems that may occur.

Trends in retail sales of insecticide-treated nets and untreated nets in Tanzania: cross-section surveys

BackgroundThe commercial sector plays a vital role in mosquito net ownership and access in Tanzania. The National Malaria Strategic Plan (NMSP) includes long-lasting insecticidal nets (LLIN) delivery through the commercial sector as a complementary mechanism. The NMSP aims to increase LLIN sales while decreasing untreated mosquito net sales. This survey aimed to track quantities, market share of different net categories, prices, and origins of mosquito nets in retail markets and to engage stakeholders to analyse market trends.MethodsThis mixed-method mosquito net retail outlet survey was conducted in mid-2021 in six and in mid-2022 in eight regions. Field teams identified net-selling outlets in major urban and peri-urban markets and used snowball sampling to identify additional outlets. A structured questionnaire was used, and photos of available mosquito net products were taken. Key informant interviews were conducted with wholesalers and retailers. The relative market share of a product was calculated by using the mean of each sales category as frequency weights. Qualitative data analysis was undertaken by summarizing common themes and observations based on the research question.ResultsA total of 394 and 1139 outlets were surveyed in 2021 and 2022, respectively. More than 96% of distributed brands in both years were untreated nets. The market share for untreated mosquito nets was 99.2% in 2021 and 88.3% in 2022. Bed net sales were seasonal, peaking in the rainy season and at the start of the school year. Leaked LLINs from the public sector comprised 0.3% of the market share in 2021 and 8.3% in 2022. Kigoma markets had the most significant frequency of leaked LLIN products. Legitimate LLINs were rare in 2021 (n = 2) and not found in 2022, despite the presence of a local LLIN manufacturer. A small number (n = 3) of untreated nets fabricated in China claiming to be LLINs were observed in 2022.ConclusionsDespite NMCP’s strategic approach to increasing retail market share for legitimate LLINs, significant challenges remain. Efforts are needed to change the current situation given the context of large-scale public sector distributions of LLINs, the higher consumer cost of LLINs, the lack of bed net varieties. Improvement of registration process is recommended.

Evaluation of An Aerial Application of Duet Hd® Against Aedes Dorsalis and Culex Tarsalis in Rural Habitats of the Great Salt Lake, Utah.

The Salt Lake City Mosquito Abatement District (SLCMAD) has been conducting aerial applications using an organophosphate insecticide against adult mosquitoes for several decades. In order to evaluate a potential rotation product, aerial applications of Duet HD™, a pyrethroid, were conducted under operational conditions against wild populations of Aedes dorsalis and Culex tarsalis and against colony strains of Cx. pipiens and Cx. quinquefasciatus. The erratic wind patterns of the greater Salt Lake area did not prevent sufficient droplet deposition flux at 9 monitoring locations spread across a 5,120-acre (2,072 ha) spray block within rural habitats. Three separate aerial application trials showed great efficacy against Ae. dorsalis. In contrast, Cx. tarsalis exhibited inconsistent treatment-associated mortalities, suggesting the presence of less susceptible or resistant field populations as a result of spillover from agricultural or residential pyrethroid usage. Bottle bioassays to diagnose pyrethroid resistance using field-collected Cx. tarsalis indicated that some populations of this species, especially those closest to urban edges, failed to show adequate mortality in resistance assays. Despite challenging weather conditions, Duet HD worked reasonably well against susceptible mosquito species, and it may provide a crucial role as an alternative for organophosphate applications within specific and sensitive areas. However, its area-wide adoption into control applications by the SLCMAD could be problematic due to reduced impacts on the most important arboviral vector species, Cx. tarsalis, in this area. This study demonstrates the importance of testing mosquito control products under different operational environments and against potentially resistant mosquito populations by municipal mosquito control districts.

Comparative Activity And Efficacy of Sumilarv 0.5G and Altosid Xr Briquet Against Culex Quinquefasciatus and Aedes Aegypti in Simulated Catch Basins.

Mosquito control plays a crucial role in the mitigation of mosquito-borne diseases. Larviciding that targets one of the aquatic stages is among the routine practices in mosquito control operations. One of the most extensive and challenging mosquito production sources in urban environments is underground storm drain systems. Along with the research and development of biorational larvicides in recent decades, numerous products based on microbial and insect growth regulators have become available. However, the performance of these products often varies because of product design and challenges associated with urban storm drain systems. This paper validates the comparative bioactivity and semifield efficacy of 2 control release products based on pyriproxyfen and S-methoprene. In laboratory bioassays, pyriproxyfen was significantly more active than S-methoprene against the test species, Culex quinquefasciatus Say and Aedes aegypti (L.). Culex quinquefasciatus was less susceptible than Ae. aegypti to both test materials. During a 26-wk-long semifield evaluation using the cast concrete simulated catch basins, the inhibition of emergence pretreatment and posttreatment in untreated control was negligible. The Sumilarv 0.5G applied at 75 g per catch basin provided 100% IE, whereas the Altosid XR briquet applied at 1 per catch basin yielded only partial control fluctuating from 12.7% to 82.7% (average 40.7%) of Cx. quinquefasciatus and 8.0% to 78.8% (average 37.4%) of Ae. aegypti. The Altosid XR briquet had an average residual weight of 59.9% at the end of semifield evaluation. Results are discussed in relation to field mosquito control operations in urban storm drain systems.

Uji Aktivitas Larvasida Minyak Daun Kemangi (Ocinum sanctum L.) Asal Pulau Timor Terhadap Larva Nyamuk Aedes Aegypti

The tropical climate in regions like Timor Island can lead to the proliferation of disease-carrying mosquitoes such as Aedes aegypti, which are responsible for diseases like dengue fever, filarial infections, and elephantiasis. Dengue Hemorrhagic Fever (DHF) is a major concern in Indonesia, particularly in East Nusa Tenggara (NTT). This research aimed to assess the effectiveness of basil leaf oil (Ocimum Sanctum L.) as a natural substitute for electric mosquito repellents. The study focused on evaluating its impact on the mortality of Aedes aegypti mosquito larvae and determining the LC50 (Lethal Concentration 50) of basil leaf oil against these larvae. Basil leaves (Ocimum Sanctum L.) were used to extract basil leaf oil through distillation, followed by separating water and oil. The study employed a randomized block design (RAK) to conduct experiments on mosquito larvae. The larvicidal activity of basil leaf oil was tested using 5 different concentrations: 750 ppm, 1000 ppm, 1500 ppm, 2000 ppm, and 5000 ppm. A control group containing 70% alcohol was also included. Ten Aedes aegypti mosquito larvae were transferred from a holding container to a beaker containing 100 mL of distilled water mixed with basil leaf oil at the specified concentrations. The larvae were observed at 5, 10, 15, and 20-minute intervals to track the mortality rate of the larvae over time. The findings of the research demonstrated that basil leaf oil (Ocimum Sanctum L.) exhibited larvicidal activity against Aedes aegypti mosquito larvae. The mortality rate of the larvae increased as the concentration of basil leaf oil increased, with the most significant impact observed at a concentration of 2000 ppm. This study highlights the potential of basil leaf oil as a natural larvicide against Aedes aegypti mosquito larvae, which are responsible for transmitting diseases like dengue fever. The results suggest that basil leaf oil could serve as an alternative or complementary method to conventional mosquito control strategies. Given the importance of controlling mosquito-borne diseases, the use of locally available plant-based substances like basil leaf oil could contribute to public health efforts, particularly in regions like East Nusa Tenggara (NTT). Further research and development in this area could lead to the creation of effective and environmentally friendly mosquito control products.

Optimization of Dieldrin Selection for the Genetic Sexing of Aedes albopictus.

The mass production of mosquitoes at an industrial scale requires efficient sex separation, which can be achieved through mechanical, genetic or artificial intelligence means. Compared with other methods, the genetic sexing approach offers the advantage of limiting costs and space by removing females at the larval stage. We recently developed a Genetic Sexing Strain (GSS) in Aedes albopictus based on the sex linkage of the rdlR allele, conferring resistance to dieldrin, to the male (M) locus. It has been previously reported that dieldrin ingested by larvae can be detected in adults and bioaccumulated in predators, raising the question of its use at a large scale. In this context, we performed several experiments aiming at optimizing dieldrin selection by decreasing both dieldrin concentration and exposure time while maintaining a stable percentage of contaminating females averaging 1%. We showed that the previously used dieldrin exposure induced an important toxicity as it killed 60% of resistant males at the larval stage. We lowered this toxicity by reducing the dose and/or the exposure time to recover nearly all resistant males. We then quantified the residues of dieldrin in resistant male adults and showed that dieldrin toxicity in larvae was positively correlated with dieldrin concentrations detected in adults. Interestingly, we showed that the use of reduced dieldrin exposure led to a dieldrin quantification in adult males that was below the quantity threshold of the Gas Chromatography-Mass Spectrometry detection method. Presented data show that dieldrin exposure can be adjusted to suppress toxicity in males while achieving efficient sexing and lowering the levels of dieldrin residues in adults to barely quantifiable levels.

Requirements for market entry of gene drive-modified mosquitoes for control of vector-borne diseases: analogies to other biologic and biotechnology products.

Gene drive-modified mosquitoes (GDMMs) are proposed as new tools for control and elimination of malaria and other mosquito-borne diseases, and promising results have been observed from testing conducted in containment. Although still at an early stage of development, it is important to begin now to consider approval procedures and market entry strategies for the eventual implementation of GDMMs in the context of disease control programs, as these could impact future research plans. It is expected that, as for other types of new products, those seeking to bring GDMMs to market will be required to provide sufficient information to allow the regulator(s) to determine whether the product is safe and effective for its proposed use. There already has been much emphasis on developing requirements for the biosafety components of the "safe and effective" benchmark, largely concerned with their regulation as genetically modified organisms. Other potential approval requirements have received little attention, however. Although GDMMs are expected to be implemented primarily in the context of public health programs, any regulatory analogies to other public health products, such as pharmaceuticals, vaccines, or chemical pesticides, must take into account the characteristics of live mosquito products. Typical manufacturing standards related to product identity, potency or quality will need to be adapted to GDMMs. Valuable lessons can be drawn from the regulatory approval processes for other whole organism and genetically modified (GM) organism products. Supply chain requirements, such as scale of production, location and design of production facilities, and methods of distribution and delivery, will be dependent upon the characteristics of the particular GDMM product, the conditions of use, and the region to be served. Plans for fulfilling supply chain needs can build upon experience in the development of other live insect products for use in public health and agriculture. Implementation of GDMMs would benefit from additional research on enabling technologies for long-term storage of mosquito life stages, efficient mass production, and area-wide delivery of GDMMs. Early consideration of these practical requirements for market entry will help to mitigate downstream delays in the development of these promising new technologies.

Development of an automated mosquito pupae counter.

The production of mosquitoes for control programs or basic research is facilitated by the standardization of rearing conditions allowing the daily manipulation of thousands of individuals. It is crucial to develop mechanical or electronic systems for controlling the density of mosquitoes at each development stage with the aim of reducing costs, time, and human errors. We present herein an automatic mosquito counter using a recirculating water system allowing rapid and reliable counting of pupae without detectable increased mortality. Using Aedes albopictus pupae, we determined the density of pupae and the time of counting for which the device is most accurate, and evaluated the time saved using this device. Lastly, we discuss how this mosquito pupae counter can be useful in small-scale or mass-rearing contexts enabling a number of applications for research purposes as well as operational mosquito control programs.

Numerical Simulation on Three-Dimensional Printed Submerged Temephos Larvicide Dispenser for Dengue Prevention

Implementation of computer simulation analysis of proposed Temephos submerged dispensers designated as “Floater 1” and “Floater 2” presented in this study contributes to a body of research on the types of interventions used to prevent mosquito-borne diseases. Floaters 1 and 2 are known as cage and cylindrical design, respectively. Modal analysis conducted on both design enabled the authors to further understand and visualize the deformation and stress distribution which correspond to natural frequency of each design. Obtained natural frequency of these dispensers could avoid destructive frequencies caused by external loads acting on both designs. Furthermore, costs related to destructive testing and manufacturing defects would literally be avoided. Hence, a more robust and affordable mosquito control product will potentially be materialized. Combined usage of these submerged dispensers made of polylactic acid (PLA), an environmentally friendly plastic printed via 3D printing with reused or recycled plastic material will gain a widespread use and contribute to the environmental sustainability.

The Promise and Challenge of Genetic Biocontrol Approaches for Malaria Elimination.

Malaria remains an ongoing public health challenge, with over 600,000 deaths in 2021, of which approximately 96% occurred in Africa. Despite concerted efforts, the goal of global malaria elimination has stalled in recent years. This has resulted in widespread calls for new control methods. Genetic biocontrol approaches, including those focused on gene-drive-modified mosquitoes (GDMMs), aim to prevent malaria transmission by either reducing the population size of malaria-transmitting mosquitoes or making the mosquitoes less competent to transmit the malaria parasite. The development of both strategies has advanced considerably in recent years, with successful field trials of several biocontrol methods employing live mosquito products and demonstration of the efficacy of GDMMs in insectary-based studies. Live mosquito biocontrol products aim to achieve area-wide control with characteristics that differ substantially from current insecticide-based vector control methods, resulting in some different considerations for approval and implementation. The successful field application of current biocontrol technologies against other pests provides evidence for the promise of these approaches and insights into the development pathway for new malaria control agents. The status of technical development as well as current thinking on the implementation requirements for genetic biocontrol approaches are reviewed, and remaining challenges for public health application in malaria prevention are discussed.