Control Of Mosquito Larvae Research Articles

Insect growth regulatory and larvicidal activity of chalcones against Aedes albopictus

AbstractWidespread use of chemical insecticides has resulted in development of insect resistance and natural products with biological activities could become an attractive alternative to control insect pests. In order to find more effective insecticides for controlling mosquito, various mosquitocidal compounds are studied. Recently, juvenile hormone antagonists (JHANs) have been found to be to safe and effective insecticides for control of mosquito. In order to identify novel insecticidal compounds with JHAN activity, several chalcones were surveyed on their JHAN activities and larvicidal activities against Aedes albopictus larvae. Among them, 2′‐hydroxychalcone and cardamonin showed high levels of JHAN and mosquito larvicidal activities. These results suggested that chalcones with JHAN activity could be useful for control of mosquito larvae.

Native larvivorous fish diversity as a biological control agent against mosquito larvae in an endemic malarious region of Ranchi district in Jharkhand, India

Mosquitoes are responsible for transmitting several diseases, including malaria, dengue, chikungunya, filariasis, and yellow fever, etc. Release of larvivorous fishes is one of the cheapest method of vector management approach, with long suppression of mosquito population. The present study identifies the native larvivorous fishes and evaluates their potential larvivoracity for biological control of mosquito larvae in an endemic malarious region. During the year 2012-13, an ecological descriptive study was carried out in diverse aquatic habitats of fish species found in different areas of Ranchi district, in Jharkhand state of India. Fishes were captured using fishing nets, and identified and classified according to the available keys. Their larvivorous potential was graded according to their feeding potential. Data on current conservation status as well as their abundance were also recorded and analysed. In total, 30 larvivorous fish species belonging to seven orders, 10 families and 21 genera were identified. Order Cypriniformes and the family Cyprinidae were the most ascendant group constituting 66.7 and 60%, respectively. The grading assessment of larvivorous potential for different fish species revealed that, Colisa fasciatus possess maximum larvivoracity (+ + + + +). According to the conservation, assessment and management plan (CAMP, 1998), 60% species were at lower risk near threat (LRnt), while 86.7% species were at least concerned (LC) as per the IUCN, 2017 categorisation. All fish species preferred to inhabit in freshwater. Maximum species occurrence was found in the river (63.3%). Only 30% species were bottom feeders (BF). The larvivoracity and habitat distribution analysis indicated that C. fasciatus, Oreochromis mossambica, Esomus danricus, Oryzias melastigma, Puntius sophore, P. ticto, Rasbora daniconius, R. elegans, Aplocheilus panchax, and Danio (B) rerio possess high-level larvivorous potentiality in nature and are recommended for malaria control in the study area. There is an increasing pressure on the fish fauna, of facing several threats, such as fishing, human interference, loss of habitat, overexploitation, pollution, siltation, trade, and diseases. Therefore, periodic survey and monitoring of fish biodiversity, demarcation of breeding sites, field level research study on the efficacy of these fishes, and public awareness on establishment of larvivorous fish ponds should be adopted as a part of the vector management approach in the endemic malarious region of Ranchi district in Jharkhand, India.

Field evaluation of the biolarvicide, spinosad 20 per cent emulsifiable concentrate in comparison to its 12 per cent suspension concentrate formulation against Culex quinquefasciatus, the vector of bancroftian filariasis in India.

Background & objectives:Biolarvicides may offer alternatives to chemical larvicides as these are known to be safe to environment and selective against the target species. However, only a limited number of biolarvicides have been approved for mosquito larval control. In the current study, a new formulation of spinosad, 20 per cent emulsifiable concentrate (EC) was tested for its efficacy against Culex quinquefasciatus, in comparison to its 12 per cent suspension concentrate (SC).Methods:Spinosad 20 per cent EC was tested against Cx. quinquefasciatus immature at 25, 50, 100 and 150 mg active ingredient (ai)/m[2] in cesspits, drains and abandoned wells in comparison with spinosad 12 per cent SC at the optimum field application dosage of 50 mg ai/m[2].Results:The 20 per cent EC caused 90-100 per cent reduction of pupal density for 7-14 days in cesspits, 10-17 days in drains and 14-30 days in abandoned wells at all dosages tested. At lower dosages of 25 and 50 mg ai/m[2], >90 per cent reduction of pupal density was observed for one week in cesspits and street drains and for two weeks in abandoned wells. The effective duration of control provided by the higher dosages, 100 and 150 mg ai/m[2] was 1.4 to 2 times greater than the lower dosages, 25 and 50 mg ai/m[2].Interpretation & conclusions:The findings showed that the spinosad 20 per cent EC can be used for larval control against Cx. quinquefasciatus, at the dosage of 25 mg ai/m[2] at weekly interval in cesspits and drains and at fortnightly interval in abandoned wells. Spinosad 20 per cent EC could be one of the options to be considered for larval control under integrated vector management.

The importance of being urgent: The impact of surveillance target and scale on mosquito-borne disease control

With the emergence or re-emergence of numerous mosquito-borne diseases in recent years, effective methods for emergency vector control responses are necessary to reduce human infections. Current vector control practices often vary significantly between different jurisdictions, and are executed independently and at different spatial scales. Various types of surveillance information (e.g. number of human infections or adult mosquitoes) trigger the implementation of control measures, though the target and scale of surveillance vary locally. This patchy implementation of control measures likely alters the efficacy of control.We modeled six different scenarios, with larval mosquito control occurring in response to surveillance data of different types and at different scales (e.g. across the landscape or in each patch). Our results indicate that: earlier application of larvicide after an escalation of disease risk achieves much greater reductions in human infections than later control implementation; uniform control across the landscape provides better outbreak mitigation than patchy control application; and different types of surveillance data require different levels of sensitivity in their collection to effectively inform control measures. Our simulations also demonstrate a potential logical fallacy of reactive, surveillance-driven vector control: measures stop being implemented as soon as they are deemed effective. This false sense of security leads to patchier control efforts that will do little to curb the size of future vector-borne disease outbreaks. More investment should be placed in collecting high quality information that can trigger early and uniform implementation, while researchers work to discover more informative metrics of human risk to trigger more effective control.

Mosquitocidal activity of penfluridol as juvenile hormone antagonist

Juvenile hormone antagonists (JHANs) are known to interfere with the formation of juvenile hormone (JH) receptor complex. JHANs might be effective for control of target pests in larval stages at which stages high level of endogenous JH titer is maintained. In order to identify novel insecticidal compounds, 2352 compounds were surveyed on their JHAN activities using the yeast-two hybrid system. Among 53 compounds with JHAN activities, penfluridol showed high level of insecticidal activity against larvae of Aedes albopictus. JHAN activity was increased in proportion to the concentration of penfluridol. Larvicidal activity of penfluridol was 1.3–2.0 folds higher than that of pyriproxyfen. These results suggested that penfluridol could be useful for control of mosquito larvae.

Pemberian Ekstrak Biji Alpukat (Persea americana Mill.) dan Biji Sirsak (Annona muricata L.) terhadap Mortalitas Larva Nyamuk Culex Sp

Vegetable insecticide is a natural material that is environmentally friendly. This material can be used in the prevention and control of mosquito larvae, especially Culex sp. Culex sp is the main vector of filariasis disease and dengue hemorrhagic fever (DHF). Use of natural materials is very good and environment friendly as insectcide compared with chemicals. Avocado seed extract (Persea americana Mill) is known to have secondary metabolite content of alkaloids, saponins, triterpenoids while soursop extract (Annona muricata L) in the form of acetogenin, squamocin and annonacin. This research needs to use of avocado seed extract (P. americana Mill) and soursop seed extract (A. muricata L) as larvacide of Culex sp. The aim of this research is to know the effect of avocado seed extract (P. americana Mill) and soursop seed extract (A. muricata L) to mortality of Culex sp Instar III mosquito larvae and LC50 for 24 hours. This study was an experimental study using a complete randomized design (RAL) with five treatment concentrations (0, 2, 4, 6, and 8%) avocado seed extract (P. americana Mill) and soursop extracts extract (A. muricata L) as much as five repetitions. The data obtained were analyzed by using One Way ANOVA to show the effect on the treatment. The results showed that giving of avocado seed extract (P. americana Mill) with 8% concentration (23,8 ± 0,45 larvae) was optimal in killing Culex sp mosquito larvae. While giving soursop seed extract (A. muricata L) with 4% concentration (25 ± 0,0 larva) optimal in killing Culex sp mosquito larvae. Avocado seed extract (P. americana Mill) has an effect as a larvacide against Culex sp. instar III with LC50 at concentration 2,486% while soursop extract (A. muricata L) with LC50 value at concentration 1,605%.
 
 Keywords: Larvacide, soursop seed extract, avocado seed extract, Culex sp

Phytochemical Properties and Insecticidal Potential of Volatile Oils from Tanacetum persicum and Achillea kellalensis Against Two Medically Important Mosquitoes

Mosquitoes play a predominant role in the transmission of parasitic and viral diseases which are today among the greatest health problems in the world. Currently, synthetic insecticides are the most commonly used compounds for the control of larval mosquitoes. Nevertheless, the continuous and indiscriminate use of synthetic larvicides has also induced adverse effects. Essential oils obtained from plants can be an alternative to synthetic insecticides because they are highly effective, safe, and environmentally acceptable. In this study, the larval stage of Anopheles stephensi, and Culex quinnquefaciatus were exposed to serial concentrations of essential oils from Tanacetum persicum and Achillea kellalensis for 24 h under laboratory condition. In addition, the chemical composition of essential oils were determined and identified by Gas chromatography (GC) and GC-mass spectrometry (MS) analysis. Both plant oils exerted significant larvicidal activity against An. stephensi and Cx. quinquefasciatus. The LC values of T. persicum and A. kellalensis against An. stephensi larvae were 48.64 and 35.42 ppm, and for Cx. quinquefasciatus were 28.53 and 21.79 ppm, respectively. In A. kellalensis, 36 components were identified, representing 97.26 % of the oil, of which βocimene (17.72 %), linalyl acetate (15.98 %), linalool (10.83 %) and α-pinene (10.3 %) were found to be the major constituents. Twenty components were identified in the oil of T. persicum, making up 89.60 % of total composition. The main constituents were Borneol (26.4 %), chrysanthenone (16.48 %), bornyl acetate (10.68 %) and βfarnesene (9.89 %). Our results suggested that both examined oils may be explored as a natural larvicide to control vector mosquitoes.

Dragonfly (Odonata) Species Diversity in Different Land Use Patterns of Lowland Tropical Wet Zone, Colombo District of Sri Lanka

Many species of Odonates inhabiting in agro-ecosystems, play a crucial role in controlling pest populations and can be considered as a pollution indicator. Damselflies are important bio-control agents especially in the control of mosquito larvae. Individual Odonata species have a wide range of environmental tolerances, and are good indicators of ecosystem health, particularly for wetlands. Odonata are also known to be highly responsive to ecosystem conditions in relation to broad-scale factors such as climate and urbanization. Huge knowledge gap displays in ecology of Odonata species and this preliminary study would provide a considerable knowledge on formulating conservation strategies and ecosystem services of dragonflies. The ecological survey examined the Dragonfly & Damselfly (Odonata) species diversity and habitat preference in different land use types at low country wet zone of Colombo district, Sri Lanka. Five (05) main land use patterns were selected as sub-urban land set up at Waga Area: a natural forest (Indikada Mukalana), a rubber plantation, a paddy field as an agricultural land use; Urban land setup: The Open university premises (OUSL) at Nawala,Colombo and “Diyatha Uyana” Battaramulla. The ecological survey was carried out with layout of belt transect (100m×2.5 ) adjacent (5-15 m distance) to selected water ways in each different sampling areas of different land use patterns which adapting purposive random sampling technique. Visual observations will be carried out adapting internationally accepted techniques for sampling of flying insects to identify and quantify of Dragonflies. Dragonfly and damselfly species specific parameters were recorded in selected sampling sites.Total number of 26 Odonata species including 09 endemics was recorded in all land using patterns all land use patterns. Species diversity (richness and abundance) measured within study sites using Shannon wiener index indicated that the paddy field (2.185), rubber plantation (1.885), natural forest (0.9507), OUSL along polluted Wellawatte canal (0.6745) and Diyatha Uyana (0.619) respectively. The number of dragonfly species and abundance is remarkably higher in urban sites while number of damselfly is higher in sub-urban paddy field and rubber plantation. Neurothemis tulia and Rhyothemis variegata species were recorded at all study sites except natural forest. Brachythemis contaminata is the most abundant species which is only recorded in urban sites. A considerable species diversity and variation of Odonata species among study sites were recognized. As a conclusive remark, further studies on find limiting factors for diversity, distribution and abundance of dragonfly & damselfly species is recommended. Keywords: Dragonfly diversity, Different land uses, Lowland wet zone, Colombo

Risks associated with introduction of poeciliids for control of mosquito larvae: first record of the non-native Gambusia holbrooki in Argentina.

This study confirms the presence of two species of the non-native mosquitofish Gambusia in Argentina. The risks that they represent to native biota, their potential dispersal in the region, and their effectiveness in mosquito larvae control are discussed.

Do Multi-year Applications of Bacillus thuringiensis subsp. israelensis for Control of Mosquito Larvae Affect the Abundance of B. cereus Group Populations in Riparian Wetland Soils?

Bacillus thuringiensis subsp. israelensis (Bti) is a soil-borne bacterium affiliated to the Bacillus cereus group (Bcg) and has been used in biocontrol products against nematoceran larvae for several decades. However, knowledge is limited on whether long-term Bti application can affect the structure of indigenous communities of Bcg and the overall abundance of Bti. Using species- and group-specific quantitative PCR assays, we measured the Bcg- and Bti-abundances in riparian wetlands in the River Dalälven floodplains of central Sweden. On five occasions during one vegetative season, soil samples were collected in alder swamps and wet meadows which had been treated with Bti for mosquito larvae control during the preceding 11years, as well as in untreated control sites and well-drained forests in the same area. The average abundance of Bcg in alder swamps was around three times higher than in wet meadows. Across all sites and habitats, the Bti treatments had no effect on the Bcg-abundance, whereas the Bti-abundance was significantly higher in the treated than in the control sites. However, for individual sampling sites, abundances of Bti and Bcg were not correlated with the number of Bti applications, indicating that added Bti possibly influenced the total population of Bti in the short term but had only a limited effect in the longer term. The findings of this study increase the understanding of the ecology of Bti applications for mosquito control, which can facilitate environmental risk assessment in connection with approval of microbiological control agents.

Larvicidal activity of lignans and alkaloid identified in Zanthoxylum piperitum bark toward insecticide-susceptible and wild Culex pipiens pallens and Aedes aegypti

BackgroundThe yellow fever mosquito, Aedes aegypti, and the common house mosquito, Culex pipiens pallens, transmit dengue fever and West Nile virus diseases, respectively. This study was conducted to determine the toxicity of the three lignans (–)-asarinin, sesamin and (+)-xanthoxylol-γ,γ-dimethylallylether (XDA), and the alkaloid pellitorine from Zanthoxylum piperitum (Rutaceae) bark to third-instar larvae from insecticide-susceptible C. pipiens pallens and Ae. aegypti as well as wild C. pipiens pallens resistant to deltamethrin, cyfluthrin, fenthion, and temephos.MethodsThe toxicities of all isolates were compared with those of mosquito larvicide temephos. LC50 values for each species and their treatments were significantly different from one another when their 95% confidence intervals did not overlap.ResultsXDA was isolated from Z. piperitum as a new larvicidal principle. XDA (LC50, 0.27 and 0.24 mg/l) was 4, 53, and 144 times and 4, 100, and 117 times more toxic than pellitorine, sesamin, and asarinin toward larvae from susceptible C. pipiens pallens and Ae. aegypti, respectively. Overall, all the isolates were less toxic than temephos (LC50, 0.006 and 0.009 mg/l). These constituents did not differ in toxicity to larvae from the two Culex strains. The present finding indicates that the lignans and alkaloid and the insecticides do not share a common mode of larvicidal action or elicit cross-resistance.ConclusionNaturally occurring Z. piperitum bark-derived compounds, particularly XDA, merit further study as potential mosquito larval control agents or as lead compounds for the control of insecticide-resistant mosquito populations.

Three-dimensional structures of the tracheal systems of Anopheles sinensis and Aedes togoi pupae

Mosquitoes act as a vector for the transmission of disease. The World Health Organization has recommended strict control of mosquito larvae because of their “few, fixed, and findable” features. The respiratory system of mosquito larvae and pupae in the water has a weak point. As aquatic organisms, mosquito larvae and pupae inhale atmosphere oxygen. However, the mosquito pupae have a non-feeding stage, unlike the larvae. Therefore, detailed study on the tracheal system of mosquito pupae is helpful for understanding their survival strategy. In this study, the three-dimensional (3D) structures of the tracheal systems of Anopheles sinensis and Aedes togoi pupae were comparatively investigated using synchrotron X-ray microscopic computed tomography. The respiratory frequencies of the dorsal trunks were also investigated. Interestingly, the pupae of the two mosquito species possess special tracheal systems of which the morphological and functional features are distinctively different. The respiratory frequency of Ae. togoi is higher than that of An. sinensis. These differences in the breathing phenomena and 3D structures of the respiratory systems of these two mosquito species provide an insight into the tracheal systems of mosquito pupae.

Phytochemical Profile and Mosquito Larvicidal Activity of the Essential Oil from Aerial Parts of Satureja bachtiarica Bunge Against Malaria and Lymphatic Filariasis Vectors

Mosquitoes play an important role in transmission of large number of diseases including malaria, filariasis and arboviral diseases. Increasing application of synthetic insecticides may be resulted in resistant to insecticides. Furthermore, it may have adverse effects on the environment and human health. Currently, one of the most effective alternative approaches under the biological control programs is using of natural larvicidal agents derived from plants. The larvicidal properties of essential oil obtained from the aerial parts of an indigenous plant, Satureja bachtiarica was evaluated against two mosquito vector, Anopheles stephensi and Culex quinquefasciatus. In addition, the analysis of essential oil was investigated by Gas chromatography-Mass spectrometry (GC-MS). Forty-one compounds, representing 98.42% of the essential oils have been identified. The main constituents were carvacrol (22.66%), p-cymene (15.89%), borneol (14.05 %), 1,8-cineole (10.45%) and thymol (7.27%). Five different concentrations of essential oil were evaluated against the late 3rd and early 4th instars larvae of An. stephensi and Cx. quinquefasciatus. The LC50 and LC90 values against An. stephensi larvae were 24.27 and 54.24 ppm and for Cx. quinquefasciatus were 44.96 and 114.45 ppm after 24 hours of exposure, respectively. In conclusion, results of study clearly indicated that the essential oils of S. bachtiarica possessed remarkable larvicidal properties and could serve as an alternative to synthetic insecticides for control of mosquito larvae.

Control of mosquito larvae in catch basins using pyriproxyfen and the mechanism underlying residual efficacy

Control of mosquito larvae in catch basins using pyriproxyfen and the mechanism underlying residual efficacy

Using an intervention mapping approach for planning, implementing and assessing a community-led project towards malaria elimination in the Eastern Province of Rwanda.

BackgroundActive community participation in malaria control is key to achieving malaria pre-elimination in Rwanda. This paper describes development, implementation and evaluation of a community-based malaria elimination project in Ruhuha sector, Bugesera district, Eastern province of Rwanda.MethodsGuided by an intervention mapping approach, a needs assessment was conducted using household and entomological surveys and focus group interviews. Data related to behavioural, epidemiological, entomological and economical aspects were collected. Desired behavioural and environmental outcomes were identified concurrently with behavioural and environmental determinants. Theoretical methods and their practical applications were enumerated to guide programme development and implementation. An operational plan including the scope and sequence as well as programme materials was developed. Two project components were subsequently implemented following community trainings: (1) community malaria action teams (CMATs) were initiated in mid-2014 as platforms to deliver malaria preventive messages at village level, and (2) a mosquito larval source control programme using biological substances was deployed for a duration of 6 months, implemented from January to July 2015. Process and outcome evaluation has been conducted for both programme components to inform future scale up.ResultsThe project highlighted malaria patterns in the area and underpinned behavioural and environmental factors contributing to malaria transmission. Active involvement of the community in collaboration with CMATs contributed to health literacy, particularly increasing ability to make knowledgeable decisions in regards to malaria prevention and control. A follow up survey conducted six months following the establishment of CMATs reported a reduction of presumed malaria cases at the end of 2014. The changes were related to an increase in the acceptance and use of available preventive measures, such as indoor residual spraying and increase in community-based health insurance membership, also considered as a predictor of prompt and adequate care. The innovative larval source control intervention contributed to reduction in mosquito density and nuisance bites, increased knowledge and skills for malaria control as well as programme ownership.ConclusionThis community-based programme demonstrated the feasibility and effectiveness of active community participation in malaria control activities, which largely contributed to community empowerment and reduction of presumed malaria in the area. Further studies should explore how gains may be sustained to achieve the goal of malaria pre-elimination.

Acoustic Control of Mosquito Larvae In Artificial Drinking Water Containers

Emerging technology designed to kill mosquito larvae with sound waves may present a nonchemical and nonbiological alternative to reduce larval populations of key medically important mosquito species such as Aedes aegypti in containers or catchments of water. These devices could benefit integrated vector management programs facing public resistance to the use of chemical or biological larvicides in stored drinking water. In this study we investigate the efficacy of a Larvasonic SD-Mini Acoustic Larvicide device in reducing larval populations of Ae. aegypti in 3 volumes of water across a range of acoustic exposure durations. We report lethal pulse duration times for 50% and 90% mortality and optimal exposure durations for the tested water volumes.

Repellency and Larvicidal Activity of Essential oils from Xylopia laevigata, Xylopia frutescens, Lippia pedunculosa, and Their Individual Compounds against Aedes aegypti Linnaeus.

In order to find new alternatives for vector control and personal protection, we evaluated the larvicidal and repellent activity of essentials oils from plants found in the Northeast of Brazil against Aedes aegypti Linnaeus mosquitoes. The plants tested include Xylopia laevigata, Xylopia frutescens, and Lippia pedunculosa and their major compounds, piperitenone oxide, and (R)-limonene. The essential oil of L. pedunculosa and its major volatile compounds were shown to be toxic for Ae. aegypti larvae with a LC50 lower than 60ppm. The essential oil of plants from the Xylopia genus, on the other hand, showed no activity against Ae. aegypti, proving to be toxic to mosquito larvae only when concentrations were higher than 1000ppm. All plants tested provided some degree of protection against mosquitoes landing, but only the essential oil of L. pedunculosa and the volatile compound piperitenone oxide suppressed 100% of mosquitoes landing on human skin, in concentrations lower than 1%. Among the plants studied, the essential oil of L. pedunculosa and its volatiles compounds have shown the potential for the development of safe alternative for mosquito larvae control and protection against Ae. aegypti mosquito bites.

Evaluation of Commercial Agrochemicals as New Tools for Malaria Vector Control.

Malaria is a vector-borne and life-threatening disease caused by parasites that are transmitted to people through the bites of infected female Anopheles mosquitoes. The vector control insecticide market represents a small fraction of the crop protection market and is estimated to be valued at up to $500 million at the active ingredient level. Insecticide resistance towards the current WHOPES-approved products urgently requires the development of new tools to protect communities against the transmission of malaria. The evaluation of commercial products for malaria vector control is a viable and cost effective strategy to identify new malaria vector control products. Several examples of such spin-offs from crop protection insecticides are already evidencing the success of this strategy, namely pirimiphos-methyl for indoor residual sprays and spinosad, diflubenzuron, novaluron, and pyriproxifen for mosquito larvae control, a supplementary technology for control of malaria vectors. In our study the adulticidal activities of 81 insecticides representing 23 insecticidal modes of action classes, 34 fungicides from 6 fungicidal mode of action classes and 15 herbicides from 2 herbicidal modes of action classes were tested in a newly developed screening system. WHOPES approved insecticides for malaria vector control consistently caused 80-100% mortality of adult Anopheles stephensi at application rates between 0.2 and 20 mg active ingradient (AI) litre-1. Chlorfenapyr, fipronil, carbosulfan and endosulfan showed the expected good activity. Four new insecticides and three fungicides with promising activity against adult mosquitoes were identified, namely the insecticides acetamiprid, thiamethoxam, thiocyclam and metaflumizone and the fungicides diflumetorin, picoxystrobin, and fluazinam. Some of these compounds certainly deserve to be further evaluated for malaria vector control. This is the first report describing good activity of commercial fungicides against malaria vectors.

Modeling and control of local outbreaks of West Nile virus in the United States

West Nile virus (WNV) was first detected in the United States (U.S.) during an outbreak in New York City in 1999 with 62 human cases including seven deaths. In 2001, the first human case in Florida was identified, and in Texas and California it was 2002 and 2004, respectively. WNV has now been spread to almost all states in the US. In 2015, the Center for Disease Control and Prevention (CDC) reported 2,175 human cases, including 146 deaths, from 45 states. WNV is maintained in a cycle between mosquitoes and animal hosts in which birds are the predominant and preferred reservoirs while most mammals, including humans, are considered dead-end hosts, as they do not appear to develop high enough titers of WNV in the blood to infect mosquitoes. In this article, we propose a deterministic model by including interactions among mosquitoes, birds, and humans to study the local transmission dynamics of WNV. To validate the model, it is used to simulate the WNV human data of infected cases and accumulative deaths from 1999 to 2013 in the states of New York, Florida, Texas, and California as reported to the CDC. These simulations demonstrate that the epidemic of WNV in New York, Texas, and California (and thus in the U.S.) has not reached its equilibrium yet and may be expected to get worse if the current control strategies are not enhanced. Mathematical and numerical analyses of the model are carried out to understand the transmission dynamics of WNV and explore effective control measures for the local outbreaks of the disease. Our studies suggest that the larval mosquito control measure should be taken as early as possible in a season to control the mosquito population size and the adult mosquito control measure is necessary to prevent the transmission of WNV from mosquitoes to birds and humans.

The Eye of the Tiger, the Thrill of the Fight: Effective Larval and Adult Control Measures Against the Asian Tiger Mosquito, Aedes albopictus (Diptera: Culicidae), in North America.

The Asian tiger mosquito, Aedes albopictus (Skuse), is a highly invasive container-inhabiting species with a global distribution. This mosquito, similar to other Stegomyia species such as Aedes aegypti (L.), is highly adapted to urban and suburban areas, and commonly oviposits in artificial containers, which are ubiquitous in these peridomestic environments. The increase in speed and amount of international travel and commerce, coupled with global climate change, have aided in the resurgence and expansion of Stegomyia species into new areas of North America. In many parts of their range, both species are implicated as significant vectors of emerging and re-emerging arboviruses such as dengue, chikungunya, and now Zika. Although rapid and major advances have been made in the field of biology, ecology, genetics, taxonomy, and virology, relatively little has changed in the field of mosquito control in recent decades. This is particularly discouraging in regards to container-inhabiting mosquitoes, because traditional integrated mosquito management (IMM) approaches have not been effective against these species. Many mosquito control programs simply do not possess the man-power or necessary financial resources needed to suppress Ae. albopictus effectively. Therefore, control of mosquito larvae, which is the foundation of IMM approaches, is exceptionally difficult over large areas. This review paper addresses larval habitats, use of geographic information systems for habitat preference detection, door-to-door control efforts, source reduction, direct application of larvicides, biological control agents, area-wide low-volume application of larvicides, hot spot treatments, autodissemination stations, public education, adult traps, attractive-toxic sugar bait methods, lethal ovitraps, barrier-residual adulticides, hand-held ultra-low-volume adulticides, area-wide adulticides applied by ground or air, and genetic control methods. The review concludes with future recommendations for practitioners, researchers, private industry, and policy makers.