RESUMEN
The distribution of container mosquitoes in relation to distances from forests was studied in temperate Japan. Mosquito larvae were collected between May and September in 4 years from tree holes, bamboo stumps, riverine rock pools, and artificial containers; sampling ranged spatially from the mountain forest across the deforested plain developed as agriculture and urban areas to the seacoast. Although tree holes, bamboo stumps, and artificial containers existed throughout the deforested plain area, 10 container species of 6 genera were found virtually only within 5 km from the nearest forest edge. Worldwide invasive Aedes albopictus (Skuse) and Aedes japonicus (Theobald) of Asian origin showed unique occurrence patterns different from other container species and from each other. Ae. japonicus was dominant in artificial containers in and near the forest but minor in forest natural containers and only occurred within 5 km from the forest. Ae. albopictus was minor in the forest irrespective of container types but not bound to the forest and dominant in natural and artificial containers throughout rural and urban areas. The 5-km range was designated as the circum-forest zone for container mosquitoes (except Ae. albopictus) in Japan, and an expanded concept, circum-boundary zone, is proposed. The widths of these zones primarily depend on the dispersal traits of mosquitoes. Whether the relation of Ae. albopictus and Ae. japonicus to forests we observed are common in the native and invasive ranges is discussed. The study of across-ecosystem dispersal is important for mosquito management under anthropogenically changing environments due to either deforestation or green restoration.
Asunto(s)
Aedes , Distribución Animal , Especies Introducidas , Animales , Japón , Aedes/fisiología , Bosques , Culicidae/fisiología , Larva/fisiología , Larva/crecimiento & desarrollo , Ciudades , EcosistemaRESUMEN
In the last 2 decades, there has been an increase in the geographic range and frequency of vector-borne diseases. Management of mosquito populations has become challenging due to increasing rates of resistance to existing insecticidal products and formulations. Several alternative tools have emerged to suppress or replace mosquito populations. One of these tools is the In2Care Mosquito Station (In2Care station). This dual-action station contains the insect growth regulator pyriproxyfen which disrupts the development of immatures and the entomopathogenic fungus Beauveria bassiana (B. bassiana) strain GHA which kills exposed adult mosquitoes. The In2Care stations have previously been shown to effectively control Aedes aegypti in field settings at a density of 6 stations/acre rather than the label-recommended 10 stations/acre. To further test the efficacy of low station density deployment, we deployed In2Care stations in the Pleasant Street Historic District of Gainesville, Florida, at a density of 3 stations/acre over a period of 2 years in the presence or absence of ground larvicidal applications. The deployment of stations resulted in no measurable impact on Ae. aegypti and Culex quinquefasciatus adult or immature abundance suggesting that the low-density deployment of In2Care stations is insufficient to reduce Ae. aegypti and Cu. quinquefasciatus abundance within treatment areas.
Asunto(s)
Aedes , Beauveria , Culex , Control de Mosquitos , Animales , Aedes/crecimiento & desarrollo , Control de Mosquitos/métodos , Culex/crecimiento & desarrollo , Florida , Beauveria/fisiología , Piridinas , Control Biológico de Vectores/métodos , Hormonas Juveniles , Insecticidas , Larva/crecimiento & desarrollo , Densidad de Población , FemeninoRESUMEN
BACKGROUND: With a shortage of effective options for control of Aedes aegypti in Puerto Rico due to widespread resistance to conventional mosquito adulticides, an alternative approach was investigated to reduce vector populations. In two areas (totaling 144 ha) of the municipality of Bayamón, Puerto Rico, Bacillus thuringiensis israelensis (Bti) AM65-52 WDG was applied at a rate of 500 g/ha using vehicle-mounted aqueous wide-area larvicide spray applications weekly for 4 weeks and then every other week for a further 16 weeks. Bioassay jars were placed in the field to monitor for deposition of Bti droplets in open spaces, and under vegetation and building coverage. Autocidal gravid ovitraps were placed throughout the field site to monitor the population of adult female Ae. aegypti in both treatment and control sites. RESULTS: Larvicide spray was successfully deposited into jars in an array of open and covered locations, as confirmed by larval bioassays. After the fourth weekly spraying, differences in autocidal gravid ovitrap densities were observed between treatment and control sites resulting in 62% (P = 0.0001) and 28% (P < 0.0001) reductions in adult female Ae. aegypti numbers. CONCLUSION: Repeated wide-area larvicide spray application of Bti AM65-52 WDG to residential areas in Puerto Rico effectively suppressed dengue vector populations. The success of this trial has led to expansion of the WALS® program to a larger area of Bayamón and other municipalities in Puerto Rico. © 2020 Society of Chemical Industry.
Asunto(s)
Aedes , Bacillus thuringiensis , Animales , Femenino , Larva , Control de Mosquitos , Mosquitos Vectores , Puerto RicoRESUMEN
Container mosquitoes (Diptera: Culicidae) oviposit their eggs in both natural and artificial containers. Many container mosquito species also serve as important vectors of disease-causing pathogens including Aedes aegypti, Ae. albopictus, and Ae. triseriatus. Control of these species can be done through the use of adulticide sprays. The efficacy of these treatments is highly dependent on the insecticide susceptibility status of the local mosquito populations. This paper provides protocols on collecting and rearing container mosquitoes for use in the Centers for Disease Control and Prevention (CDC) bottle bioassay. A brief description of the CDC bottle bioassay is provided as well as a standardized protocol for the incorporation of a 24-h mortality to the CDC bottle bioassay. Results from this 24-h holding addition to the CDC bottle bioassay reveal that some forms of resistance may be missed without the incorporation of the additional mortality reading. These protocols provide a foundation for new laboratories to establish rearing protocols and begin conducting resistance monitoring.
Asunto(s)
Aedes , Entomología/métodos , Control de Mosquitos/métodos , Mosquitos Vectores , Animales , Manejo de Especímenes/métodosRESUMEN
Aedes aegypti and Aedes albopictus are invasive mosquito species with geographic ranges that have oscillated within Florida since their presence was first documented. Local transmission of dengue, chikungunya, and Zika viruses serves as evidence of the public health importance of these two species. It is important to have detailed knowledge of their distribution to aid in mosquito control efforts and understand the risk of arbovirus transmission to humans. Through a partnership involving the University of Florida Institute of Food and Agricultural Sciences Cooperative Extension Service and the Florida Medical Entomology Laboratory; the Florida Department of Health; and mosquito control agencies throughout Florida, a container mosquito surveillance program involving all life stages was launched in the summer of 2016 to detect the presence of Ae. aegypti and Ae. albopictus. Results from this survey were mapped to provide a picture of the current known distribution of Ae. aegypti and Ae. albopictus in Florida. Aedes aegypti and/or Ae. albopictus were detected in the 56 counties that were part of the survey. Only Aedes albopictus was detected in 26 counties, primarily in the panhandle region of Florida. The results of this work underscore the importance of maintaining container mosquito surveillance in a state where chikungunya, dengue, and Zika viruses are present and where there is continued risk for exotic arbovirus introductions.
Asunto(s)
Aedes/virología , Fiebre Chikungunya/prevención & control , Dengue/prevención & control , Control de Mosquitos , Mosquitos Vectores/virología , Infección por el Virus Zika/prevención & control , Animales , Fiebre Chikungunya/transmisión , Fiebre Chikungunya/virología , Dengue/transmisión , Dengue/virología , Entomología , Monitoreo Epidemiológico , Femenino , Florida/epidemiología , Geografía , Humanos , Óvulo , Estaciones del Año , Encuestas y Cuestionarios , Infección por el Virus Zika/transmisiónRESUMEN
Surveillance is not only an important tool to assess the population dynamics of vector mosquitoes, but it can also be used to control vector-borne diseases. Mosquito vectors that belong to several genera such as Anopheles, Aedes, and Culex play a crucial role in the transmission of malaria, dengue, chikungunya, Zika, and elephantiasis diseases worldwide. We tested the efficacy of two commercial-grade oviposition attractant formulations that were developed for the container-inhabiting Aedes aegypti, Aedes albopictus, and Culex quinquefasciatus mosquitoes present in urban or semi-urban environments. These attractants can lure gravid females. Field trials were conducted in residential yards during a post-rainy season in September and October. Our data showed considerable efficacy for both attractants. Aedes-attractant collected 1.6-fold more larvae (101.2 ± 10.5 larvae/trap) than the control, and Culex-attractant collected 1.27-fold more larvae (151.2 ± 12.5 larvae/trap) than the control, resulting in 0.8 and 0.7 oviposition attraction indices (OAIs), respectively. Regression analysis indicated that the Aedes-attractant was more stable than the Culex-attractant. Location and time did not alter the efficacy of these attractants. Our experiment suggests that these attractants can be used for the development of species-specific gravid traps to detect, estimate, and control the mosquito population in urban and semi-urban areas.
Asunto(s)
Aedes/efectos de los fármacos , Fiebre Chikungunya/prevención & control , Culex/efectos de los fármacos , Dengue/prevención & control , Malaria/prevención & control , Oviposición/efectos de los fármacos , Infección por el Virus Zika/prevención & control , Aedes/fisiología , Animales , Fiebre Chikungunya/transmisión , Culex/fisiología , Dengue/transmisión , Femenino , Humanos , Larva , Malaria/transmisión , Control de Mosquitos , Mosquitos Vectores/efectos de los fármacos , Mosquitos Vectores/fisiología , Infección por el Virus Zika/transmisiónRESUMEN
Knowledge about mosquito species diversity at tropical montane cloud forests (TMCFs) in Mesoamerica is scarce. Here, we present data on mosquito species richness from samples biweekly collected, from January to December 2017, in ovitraps installed in a TMCF patch at Vázquez de Coronado County, Costa Rica. Ovitraps were placed at 2.25, 1.50 and 0.75 m at 16 sampling points. During the study period we measured relative humidity and air temperature at each sampling point, and water temperature, volume and pH in each ovitrap. We collected a total of 431 mosquito larvae belonging to five taxonomic units, one identified to the genus level and four to the species level. The most common mosquito species was Culex bihaicolus Dyar & Nuñez Tovar (Diptera: Culicidae), which accounted for nearly 80% (n = 344) of the collected mosquitoes. Culex nigripalpus Theobald (Diptera: Culicidae) was the only medically important species we found and it was collected both in the dry (January to March) and rainy season (April to December). Over 95% (n = 411) of the mosquitoes were collected during the rainy season and 60% (n = 257) at 0.75 m. Among the environmental variables that we measured, only water volume and pH were significantly (P < 0.05) different between the dry and rainy season, the former increasing and the later decreasing during the rainy season. These results suggest that rainfall plays a major role regulating the phenology of the sampled mosquito species and highlight the need to screen for pathogens in Cx. nigripalpus at the study area.
Asunto(s)
Biodiversidad , Culicidae , Bosques , Animales , Costa Rica , ÓvuloRESUMEN
BACKGROUND: Control of the container-inhabiting mosquito, Aedes albopictus, is difficult using conventional methods due to its selection of cryptic peri-domestic habitats. We evaluated whether autodissemination stations can deliver sufficient pyriproxyfen to sentinel containers to produce significant pupal mortality in different habitats such as competing oviposition sites, peri-domestic habitats, junkyards and tire piles. We also tested how far the pesticide could be transferred over a 200-m range. RESULTS: Autodissemination stations performed effectively for 8-12 weeks under field conditions. Pupal mortality was reduced in sentinel cups with high-competing oviposition habitats (5 versus 20) in isolated plots; however, similar results were not seen in residential areas. Increasing the number of stations per plot (from 1 to 4) enhanced the efficacy. Peri-domestic habitat trials showed the highest pupal mortality (50.4%) and site contamination with pyriproxyfen (82.2%) among the trials. Autodissemination stations were able to contaminate habitats in a junkyard (50.0%) and tire piles (40.2%). Pyriproxyfen was detected in sentinel cups up to 200 m from stations. Detection of pyriproxyfen by residue analysis (0.005-0.741 µg L-1 ) in field samples confirmed the transfer of the insect growth regulator. CONCLUSION: Autodissemination stations have shown promising potential as a novel pest management tool against container mosquitoes in field trials in different habitats confronted by mosquito control personnel. © 2017 Society of Chemical Industry.
Asunto(s)
Aedes , Ecosistema , Insecticidas , Control de Mosquitos , Piridinas , Aedes/crecimiento & desarrollo , Animales , Control de Mosquitos/métodos , New Jersey , Pupa/crecimiento & desarrollo , Estaciones del AñoRESUMEN
BACKGROUND: The Asian tiger mosquito, Aedes albopictus (Skuse), transmits important arboviral diseases and displaces native species. This peridomestic mosquito deposits eggs in natural and artificial containers. Container larval habitats tend to be cryptic and, therefore, difficult to reach by conventional insecticide treatments. We have developed an autodissemination station that transfers the insect growth regulator, pyriproxyfen, from the station to oviposition sites. Mosquitoes visiting the station become contaminated with an oil sticker followed by pyriproxyfen powder before exiting. RESULTS: In a room (31 m(3) ) bioassay a single station consistently achieved 100% Ae. albopictus pupal mortality against 10 oviposition containers. In a greenhouse (200 m(3) ) assay with two stations and 12 oviposition cups, 91.7% of the cups had been contaminated as shown, and 57.1% pupal mortality was recorded. Pyriproxyfen transfer was also detected by visualizing mosquito 'tarsal prints' using a fluorescent dye. CONCLUSIONS: The oil and pyriproxyfen powder dual-treatment station enhanced autodissemination efficacy by increasing toxicant attachment and retention on contaminated females. The autodissemination station offers a targeted, less environmentally damaging approach to manage cryptic container species.