Gene-drive mosquitoes could transform malaria control in Africa, but their rapid, autonomous spread requires rigorous post-release monitoring. Most malaria-endemic countries already conduct some entomological surveillance, although it is often limited, fragmented, and externally funded. Molecular diagnostics are also expanding but remain mostly research focused and ad hoc. These imperfect systems offer workable foundations for strategic upgrades to support essential gene-drive monitoring. Priority investments should strengthen field-entomology, high-throughput genotyping for drive alleles and resistance, technical expertise, and integrated data for decision-making. Fortunately, first-generation gene drives already align with common phenotyping and genotyping workflows, avoiding major infrastructure overhauls, and permit simpler evaluation metrics than conventional interventions. This feature review examines key technical and operational considerations for monitoring gene drives and recommends how countries can adapt their vector surveillance systems to effectively monitor gene-drive mosquito releases.

The ecology and biology of mosquito disease vectors of the genus Aedes are highly dynamic, adapting to various climatic and topographic factors which makes their control challenging. Evidence-based control of Aedes mosquitoes requires a detailed understanding of this adaptability, which is greatly influenced by environmental dynamics. Understanding the drivers of their distribution is hence pertinent to predict disease risk. To better understand drivers and dynamics, we studied the distribution of Aedes mosquitoes in Lagos State, Nigeria, and its connection to climatic and human factors. Aedes larvae and adults were collected from eight Local Government Areas (LGAs, four urban and four rural) in Lagos State, resulting in 98 occurrence points. Using 23 environmental variables, we modeled the geographic distribution of Aedes spp. under current climatic conditions. Human population density was overlaid to estimate the risk of arboviral diseases. Although Aedes mosquitoes were found in all the eight LGAs in different proportions, species distribution varied considerably. Both Aedes aegypti and Aedes albopictus were found across the LGAs with evidence of species partitioning. Virtually all the LGAs were predicted to be highly suitable environments for Aedes mosquitoes, with only two LGAs being moderately suitable. Anthropogenic factors including the extensive accumulation of tires contribute to larval habitat availability for both Aedes aegypti and Aedes albopictus. Urban areas with high population density were also associated with increased larval habitat availability when compared with rural areas. Furthermore, the model suggests that LGAs sharing border with Ogun State are highly suitable environments for Aedes spp. Our study highlights that the main contributing factors to Aedes distribution were precipitation and temperature in the coldest quarter. This paper aims to understand how human and climatic factors affect Aedes mosquitoes distribution in Lagos State, which is crucial to prevent disease transmission.

Ticks and tick-borne pathogens (TBPs) are considered a significant public health challenge to dog owners and the public. Tick-infested dogs are more likely to transmit zoonotic diseases, like babesiosis. However, the species of ticks that serve as vectors of babesiosis in Lagos State, Nigeria, are not well-documented. Tick samples from indigenous dogs in Epe Local Government Area of Lagos State were subject to morphological identification using a microscope (Motic SMZ-171) and screened for babesiosis using Polymerase Chain Reaction (PCR). Thirty-four (34) dogs (Males: 19 (55.9%); females 15 (44.1%)) were examined and one hundred and nine (109) ticks, 30 (27.5%) males, 56(51.4 %) females, 10(9.2%) larvae, and 13 (11.9%) nymphs were collected. Some ticks are not engorged, 21 (19.3%), semi-engorged, 29(26.6 %) and engorged 59 (54.1%). The infestation rate was 28/34 (82.4 %), and Rhipicephalus sanguineus was the tick species identified through morphological analysis, while PCR identified Babesia spp. in 19/86 (22.1%) adult ticks. For early detection of potential outbreaks and identifying high-risk areas, this study recommends a larger-scale study to ascertain the prevalence of Babesia spp. and other species in different communities in Lagos State to ascertain the public health significance

Malaria continues to be a public health problem in Nigeria. Effective vector control has been acknowledged as one of the major strategies to combat malaria in Nigeria. In order to inform context-specific policies, there is need to understand the species niche/colonization and geographical distribution of local Anopheles mosquitoes in different geographical areas in Nigeria. Therefore, this study was designed to model the distribution of Anopheles gambiae s.l. in Osun State, Nigeria. Immature stages of Anopheles mosquitoes were collected from 17 Local Government Areas (LGAs) of Osun State between 2022 and 2023, resulting in the identification of over 20,000 Anopheline mosquitoes. Of these, 146 breeding sites were identified. Two sibling species of An. gambiae s.l were later confirmed using molecular techniques (An. gambiae s.s. and An. coluzzii) with 99% of the Anopheles being An. coluzzii in all the 17 LGAs. The results were modelled using Random Forest to predict their potentially suitable habitats across the entire state. A total of 23 environmental variables (19 bioclimatic and four topographic) were used in the model, resulting in maps of the potential geographical distribution of dominant vector species under current climatic conditions. The model suggests that members of the Anopheles gambiae s.l. encountered would be found in the three senatorial districts (from high to moderate), with more suitable areas in the central part of the state. Temperature-related climatic conditions seems to be ranked higher in order of variable importance that contributed to the distribution of these species. Mean diurnal range (monthly temperature fluctuation) and temperature of the coldest month seem to be strongly associated with the presence of these species. Our model suggested areas with higher monthly temperature fluctuations in the state (between 9 and 10 °C) to support the breeding of Anopheles species, and they are likely to be abundant in areas with lower temperature during the coldest month (wet season) of the year (between 18 and 19 °C). The results of this study provide a baseline data allowing decision-makers to monitor the distribution of these species and establish a management plan for future mosquito surveillance and control programs in Osun State.

Culex quinquefasciatus, a vector of lymphatic filariasis and many other arboviral infections, remains a major public health concern, especially in regions lacking access to modern vector control tools. Growing resistance to synthetic insecticides has driven interest in eco-friendly alternatives, including plant-based larvicides such as Citrus sinensis (orange) peels. This study evaluated the larvicidal activity of ethanolic C. sinensis peel extract against Cx. quinquefasciatus larvae under laboratory conditions. Air-dried orange peels were pulverized and subjected to cold maceration in ethanol. Extracts were tested at concentration of 100–8,333 ppm on third to early fourth instar larvae, with four replicates per concentration. Mortality was recorded at 24 and 48 hours. LC₅₀ and LC₉₀ values were determined using linear interpolation. Data were analyzed using one-way ANOVA followed by Tukey’s post hoc test at a 5% significance level. High concentrations (1,667–8,333 ppm) caused complete mortality (25.00 ± 0.00) within five minutes, with no significant difference among treatments (p > 0.05). At moderate concentrations, mortality followed a dose-response trend: 400 ppm resulted in 54% and 57% mortality at 24 and 48 hours, while 800 and 1000 ppm achieved 100% mortality at both time points. Estimated LC₅₀ and LC₉₀ values were 385.2 and 713.0 ppm. No control group mortality was recorded throughout the study. C. sinensis peel extract exhibits potent larvicidal activity against Cx. Quinquefasciatus, particularly at concentrations above 400 ppm. Its efficacy low cost and availability suggest potential as a natural component in integrated mosquito control strategies, particularly in resource-limited settings.

Malaria remains a global public health threat. This study investigated the larval habitat of Anopheles mosquito in Osun State, Nigeria and its public health implication. Four larval habitat types were encountered: Ground pool, gutter, container and abandoned tires. 158 specific larval habitats were identified. Inisa 53(33.5

Effectiveness of currently deployed insecticide-based malaria vector control measures depends on continuous insecticide resistance monitoring and management. Urban malaria is becoming a serious health problem in Africa partly due to vector resistance in urban areas. To provide insecticide resistance trends information for effective resistance management, this study assessed insecticide susceptibility status and occurrence of knock down resistance mutation in Anopheles mosquitoes from urban Ilorin, Nigeria in two different years. Malaria vectors in urban Ilorin were assayed for susceptibility to WHO-recommended insecticides in 2017 and 2020 using WHO test kits. Sub-sets of exposed An. gambiae s.l. mosquitoes were PCR-assayed for sibling species and knock down resistance (kdr) mutation detection. Full mosquito susceptibility (98–100

The present study reports the infectivity of An. gambiae s.l with sporozoite of Plasmodium. falciparum. Adult mosquitoes were caught quarterly in three communities across the state between 1800hr – 0600hr using the Centre for Disease Control light trap and 0600hr – 0700hr for pyrethrum spray catch (PSC) using protocol by the WHO and identified using morphological keys. Molecular analysis for sibling species identification was conducted using Polymerase Chain Reaction. The CDC light trap had a total of ninety (90) catches while the PSC had a relatively low number (1) of catch. A total of 4 samples were positive for P. falciparum. Ido-Osun 2 (50%) recorded the highest infectivity status as compared to Inisa 1(50%) and Ife 1 (50%). Infectivity was found in the first, second and third quarters respectively. The outdoor catch had the highest number of sporozoites detected across the study areas as compared to the indoor catch (p = 0.59; P > 0.05). Similarly, 1 (33.3%) sporozoite was detected in the outdoor catches across all the study areas. The only sporozoite detected indoor was found at Ido-Osun. No sample was positive for P. vivax sporozoite across the study areas. The present study therefore suggests the possibility of an ongoing transmission of falciparum malaria in the state. Therefore, the need to devise proactive control and preventive measures targeted at containing the transmission.

Accurate vector species identification is essential to distinguish the co-existence of primary and secondary vectors of malaria sustaining transmission in different settings. This evaluation reviews the identity, bionomics, and behaviour of malaria vectors where composition shifted in the forest ecological zone in Mkpat-Enin Local Government Area of Akwa Ibom State, Nigeria. Anopheline mosquito samples were collected from pyrethrum spray catch collections and CDC light traps from 2016 through 2022. Samples were morphologically identified and subjected to polymerase chain reaction assays and sequencing analysis to confirm the identity of unamplified and/or misidentified samples. Mosquito bionomics such as abundance, indoor and outdoor human biting rates (HHR), indoor resting density (IRD), biting time, Plasmodium falciparum infection and blood meal sources of the mosquito samples were determined from the 2021 and 2022 samples. Data analysis was performed using one-way ANOVA (analysis of variance) tests and chi-square tests in GraphPad Prism version 9.0. A total of eight Anopheles species were identified: Anopheles coustani, Anopheles funestus group, Anopheles gambiae sensu lato (s.l.), Anopheles maculipalpis, Anopheles marshallii group, Anopheles moucheti, Anopheles nili, and Anopheles obscurus. The outcome of the analysed data confirmed a shift in the composition from An. gambiae s.l. to the An. marshallii group. The IRD, indoor and outdoor HBR of the An. marshallii group were not significantly different from that of An. gambiae s.l. in 2021 (p > 0.05) but significantly higher in 2022 (p < 0.05). The peak indoor and outdoor HBR of the An. marshallii group were observed to be higher than those of An. gambiae s.l. during the dry season. In both years, the An. gambiae s.l. and the An. marshallii group mosquitoes showed comparable preference for bovine blood meal. The preference for human blood meal was not significantly different (p = 0.21) between both species. The An. marshallii group was found to have been infected with Plasmodium falciparum sporozoites (n = 2) alongside An. gambiae sensu stricto (s.s.) (n = 1) and Anopheles coluzzii (n = 2). The An. marshallii group was confirmed as an abundant malaria vector species in. Mkpat-Enin Local Government Area of Akwa Ibom State. While similar indoor vector control interventions are recommended for both species; other interventions may be needed to address the early evening outdoor biting observed in the An. marshallii group.

The presence of mosquitoes in an academic environment is a great threat to both staff and students’ wellbeing due to the possibility of the transmission of mosquito-borne diseases if bitten by infected mosquitoes. Thus, this study surveyed mosquitoes in male students’ hostels in Federal University of Dutse Jigawa State. The study was carried out using the pyrethroid spray catch method from 0600 hours to 0900 hours. A total of nine hundred and eighty-nine mosquitoes were collected. The predominant specie was Culex quinquefasciatus (61.53%) had a mean value of 152.25±0.20 which was significantly higher (P˂0.05) than Culex papien 7.59%, Aedes aegypti (13.0%) and then Anopheles gambiae (s.l) (7.0%) while there was the least with Ae. albopictus with 0.7% value. Mosquitoes’ abundance significantly varied (P<0.05) with the altitude of building floors in favour of ground floor hostel rooms. Transmission indices revealed two (2) mosquitoes/room and as well as one (1) mosquito/student. Up to 50% of mosquitoes caught were from rooms where no insecticide aerosols were used. About 19% of mosquitoes were caught from such rooms where the use of insecticide-treated bed nets and aerosol insecticide were used. Owing to the results recorded in this study, male students living in the hostel should avoid human-vector contact through the informed use of insecticides and treated bed nets.

Information on native mosquito species viz-a-vis the nature of their breeding sites can help determine the epidemiology of mosquito-borne diseases in an environment, hence, species of mosquito in breeding sites were surveyed in Suleja metropolis. All accessible larval habitats were surveyed between June and October, 2023 within Suleja township and New (Sabo) Gwazunu both of which are within Suleja metropolis. A total of five species: An. gambiae s.l, Cx. quinquefasciatus, Aedes albopictus, Aedes aegypti, and Cx. papiens were encountered. The mean values of larvae recovered from transient habits such as rock holes and holes on shrubs and tree bark are significantly (P ˂ 0.05) higher than larvae recovered from run-off and drums in new (Sabo) Gwazunu. Disused wheel tires had the highest species diversity in Suleja township (Shannon-Weiner index=0.60) while the highest species diversity obtained in New Gwazunu is 0.48 Shannon-Weiner index. The contribution of ecosystems, together with the increasing rate of human activity, may give an abundance of breeding grounds for mosquitoes. It is therefore recommended that the human population in Suleja metropolis should maintain environmental sanitation and management.

Mosquito survey and identification are foundational elements of an effective vector management plan. The present study therefore aimed to collect and identify various mosquito species in some selected Area Councils in the Federal Capital Territory (FCT), Nigeria. Larval of various species of mosquitoes were collected and identified in difference breeding sites across selected Area councils in the FCT. The collected larvae were raised to adult stage and were further identified using morphological key. Data obtained were analysed using SPSS version 27.0 and p-value was set at 95%. Samples were collected from Abuja Municipal, Gwagwalada and Bwari area councils. The study identified Anopheles funestus, 150(9.8%), as the least mosquito species collected and Culex quinquefasciatus, 307 (20.1) was the most abundance species in the study areas. Mosquito species co-exist in various breeding sites with Anopheles species mostly associated with temporary breeding. The study provides a baseline data concerning mosquito vector population and composition in the FCT. This information thus informs the public and vector management officials about the risks and the need to scale-up preventive measures against human-vector contact.

A survey of the malaria vectors in an area is a critical component of an effective vector control strategy. This study aimed to investigate the malaria vectors in four communities of Southern Gombe, Northeastern Nigeria. A total of 3200 adult female Anopheles reared from larvae in the four communities from two Local Government Areas (LGAs) in Southern Gombe were identified. Anopheles pretoriensis were dominant 1662 (51.9%) followed by An. gambiae sl 868(27.1%), An. maculipalpis 267(8.3), An. rufipes 252(7.9) and An. coustani 10(0.3%), and the least were An. pharoensis 6(0.2%). The remaining 135(4.3%) were unidentified. Of the 262 An. gambiae sl identified by species-specific PCR method, 135(51.5%) were found to be An. coluzzi, 60(22.9%) An. gambiae and only 1(0.4%) was An. arabiensis whereas hybrid constitutes 16(6.1%). To determine significant differences in species composition, the results from the four study sites were pooled together. Anopheles pretoriensis was significantly different from all the other species identified (p = <0.0001 - 0.0454). An. gambiae sl. was significantly different from An. coustani and An. pharoensis (p = 0.0258, 0.0249 respectively). There was no significant difference between An. maculipalpis, An. rufipes, An. coustani and An. pharoensis (p = 0.9261 - >0.9999). There was a significant difference between the number of species identified as An. coluzzi and An. arabiensis (p = 0.0025). But there was no significant difference between An. coluzzi and An. gambiae (p = 0.1212). The heterogeneity and sympatry of Anopheles species observed is a threat to malaria control as the secondary vectors have behaviour that evades the current vector control interventions. It is expedient to re-strategize the vector control interventions in the study area.

Malaria vector surveillance is required to determine disease transmission dynamics, vector insecticide susceptibility status, suitable control strategies and impact of control interventions. However, capacity and resources for vector surveillance and insecticide resistance monitoring is often inadequate in most countries at risk of vector-borne diseases. Collaborations and linkages between malaria control policy makers and existing research institutions generating vector surveillance research data are often weak, thereby hindering the availability of data for decision-making. A national vector surveillance programme, mobilizing all stakeholders towards quality data generation and policy making, is required for effective data-driven country-wide vector control. This paper provides an analysis and suggested future directions for such synergized national malaria vector surveillance and insecticide resistance monitoring system currently being implemented by all research and policy stakeholders in Nigeria. The harmonized national vector surveillance system described here can be used as a model for the development or improvement of such structures in other countries with high malaria transmission risks.

Enzymes mediated resistance development and their activities are well documented in Anopheles gambiae vectors. However, biological consequences of such resistance development in malaria vectors are obscure. The present study aims to determine the implications of such response in An. gambiae (Kisumu) population following exposure to a concentration of Permethrin selection pressure across multiple generations. Adult Kisumu mosquitoes exposed to 0.2 µg/ CDC bottle over generations were compared with unexposed control populations by way of resistance status, cost of fitness, and correlating metabolic enzymes. Data obtained were analysed using SPSS. Analysis of Variance was employed to determine statistical differences at 95%. Fecundity rates of the mosquito population dropped progressively over generations. With increase in activity of metabolic enzymes, resistance status of the mosquito population progressed significantly (P< 0.05) over generations with 5.0 µg (18.00±0.00; 72%) at f4 generation. Mosquito resistance development is therefore a disadvantage to malaria vectors as it reduces ovipository capability, and increases longevity of immature stages (life cycle) with filial generations.

Background: Edible insects and the act of eating insects (Entomophagy) are common across the globe. Feeding variations and species differences, among other factors, influence these individuals’ chemical and mineral components. The current study elucidated the nutritional composition of house cricket (Acheta do-mesticus) and dung beetle larva (Oryctes boas) collected in Osun State, Southwestern Nigeria. Methods: The nutritional composition of the two species of insects sampled randomly was determined following standard methods of the Association of Official Analytical Chemists. The ground crickets and beetle larvae were digested with HNO3 and HCl in a microwave digestion system; inductively coupled plasma-optical emission was used to determine the amounts of Calcium, Sodium, Potassium, Phosphorus, Magnesium, Iron, Copper, Manganese, and Zinc in the samples. Following a standard procedure, the amino acid profile was performed using a Biochrom30+ amino acid analyzer (Pharmacia-Biotech, Buckinghamshire, UK). Data obtained were expressed as means ± standard deviations of triplicate analyses and compared among the two insect species using Student’s t-test at p < 0.05. Results: Generally, the nutritional components of A. domesticus were higher than that of O. boas. The O. boas was not significantly higher (P> 0.05) in Iron (6. 83 ± 1. 80 mg/100 g dry matter) but significantly high-er (P< 0.05) in Magnesium (730. 94 ± 2. 64 mg/100 g dry matter) than A. domesticus. All Essential Amino Acids (EAAs) and Non-Essential Amino Acids (NEAAs) were present in the two insect species with varying concentrations. House cricket, however, has a significantly higher (P< 0.05) Arginine, Valine, Phenylalanine, Glutamine, and Glutamic Acid than O. boas. Conclusion: The two insects under this study are edible and of great nutritional values. The results of the nutritional composition of Acheta domesticus and Oryctes boas may serve as the basis for improvement in human food and feed formulation in Nigeria

The need for evidence-based data, to inform policy decisions on malaria vector control interventions in Nigeria, necessitated the establishment of mosquito surveillance sites in a few States in Nigeria. In order to make evidence-based-decisions, predictive studies using available data becomes imperative. We therefore predict the distribution of the major members of the Anopheles gambiae s.l. in Nigeria. Immature stages of Anopheles were collected from 72 study locations which span throughout the year 2020 resulted in the identification of over 60,000 Anopheline mosquitoes. Of these, 716 breeding sites were identified with the presence of one or more vector species from the An. gambiae complex and were subsequently used for modelling the potential geographical distribution of these important malaria vectors. Maximum Entropy (MaxEnt) distribution modeling was used to predict their potentially suitable vector habitats across Nigeria. A total of 23 environmental variables (19 bioclimatic and four topographic) were used in the model resulting in maps of the potential geographical distribution of three dominant vector species under current climatic conditions. Members of the An. gambiae complex dominated the collections (98%) with Anopheles stephensi, Anopheles coustani, Anopheles funestus, Anopheles moucheti, Anopheles nilli also present. An almost equal distribution of the two efficient vectors of malaria, An. gambiae and Anopheles coluzzii, were observed across the 12 states included in the survey. Anopheles gambiae and Anopheles coluzzii had almost equal, well distributed habitat suitability patterns with the latter having a slight range expansion. However, the central part of Nigeria (Abuja) and some highly elevated areas (Jos) in the savannah appear not suitable for the proliferation of these species. The most suitable habitat for Anopheles arabiensis was mainly in the South-west and North-east. The results of this study provide a baseline allowing decision makers to monitor the distribution of these species and establish a management plan for future national mosquito surveillance and control programs in Nigeria.

Onchocerciasis caused by infection with Onchocerca volvulus is a disease of public health importance and is highly associated with disability. As Nigeria is aiming at eliminating onchocerciasis by 2030, there is a need to develop newer tools to map disease prevalence and identify environmental factors driving disease prevalence, even in places that have not been previously targeted for preventive chemotherapy. This study produced predictive risk-maps of onchocerciasis in Ogun State. Georeferenced onchocerciasis infection data obtained from a cross-sectional survey at 32 locations between March and July 2015 together with remotely-sensed environmental data were analyzed using Ecological Niche Models (ENM). A total of 107 field occurrence points for O. volvulus infection were recorded. A total of 43 positive occurrence points were used for modelling. ENMs were used to estimate the current geographic distribution of O. volvulus in Ogun State. Maximum Entropy distribution modeling (MaxEnt) was used for predicting the potential suitable habitats, using a portion of the occurrence records. A total of 19 environmental variables were used to model the potential geographical distribution area under current climatic conditions. Empirical prevalence of 9.3% was recorded in this study. The geospatial distribution of infection revealed that all communities in Odeda Local Government Area (a peri-urban LGA) showed remarkably high prevalence compared with other LGAs. The predicted high-risk areas (probability > 0.8) of O. volvulus infection were all parts of Odeda, Abeokuta South, and Abeokuta North, southern part of Imeko-Afon, a large part of Yewa North, some parts of Ewekoro and Obafemi-Owode LGAs. The estimated prevalence for these regions were >60% (between 61% and 100%). As predicted, O. volvulus occurrence showed a positive association with variables reflecting precipitation in Ogun State. Our predictive risk-maps has provided useful information for the elimination of onchocerciais, by identifying priority areas for delivery of intervention in Ogun State, Nigeria.