RESUMO
Six flit-gun sprayers were tested for possible use in mosquito adulticide programs where inexpensive nonmotorized application technology may be required. An analysis of variance for differences in droplets ≤ 24 microns (µ), droplets ≥ 48 µ, droplets/cm2, volume median diameters, and mosquito mortality is provided. As shown by these data, good results can be achieved with this equipment.
Se pusieron a prueba seis atomizadores de compresión activados a mano a fin de evaluar su utilidad para programas de exterminio de mosquitos adultos en que se necesiten tecnologías no motorizadas de bajo costo. Se hace un análisis de la varianza en cuanto a partículas ≤ 24 y ≥ 48 micras (µ), partículas/cm2, diámetro del volumen mediano, y número de mosquitos muertos. Los datos confirman que pueden obtenerse buenos resultados con aparatos de este tipo.
Assuntos
Controle de Mosquitos/instrumentação , Piretrinas/administração & dosagem , Análise de Variância , Estudos de Avaliação como Assunto , SoftwareRESUMO
In an effort to develop a more effective measure for use in emergency control of the dengue vector Aedes aegypti. applications of a combination of a larvicide (Bacillus thuringiensis israelensis [B.t.i.]) and an adulticide (permethrin) were made using a truck-mounted forced-air generator (Scorpion 20) and evaluated in the Dominican Republic. This method has the potential to simultaneously control adults and larvae. In bioassay cages placed in household water containers at the time of application, larval mortalities were 95.1 and 100% for 2 application rates of permethrin mixed with B.t.i. Adult mortalities were not as impressive, probably because of resistance to permethrin. Higher adult mortality in caged specimens (78.5%) and a substantial reduction in the natural population (68.4%) of Ae. aegypti were obtained following a 2.1-g AI/ha application of deltamethrin alone.
Assuntos
Aedes , Bacillus thuringiensis , Inseticidas , Controle de Mosquitos/métodos , Piretrinas , Animais , República Dominicana , Emergências , Entomologia/métodos , Estudos de Avaliação como Assunto , Larva , Controle de Mosquitos/instrumentação , Permetrina , Controle Biológico de Vetores/métodosRESUMO
To develop a new strategy for control of exophilic/exophagic malaria vectors which rest on peridomestic foliage, Anopheles albimanus was used for laboratory bioassays of mosquito adulticides applied to various vegetation types. Of the three classes of insecticide tested, the pyrethroid (permethrin at 112 g/ha) showed greater foliar persistence than either the carbamate (bendiocarb at 340 g/ha) or the organophosphorus compound (malathion at 277 g/ha). Field evaluation of barrier spraying against An.albimanus was evaluated in rural villages of southwest Dominican Republic during 1989. The pyrethroid deltamethrin was sprayed aerially for ultra-low volume application at treatment rates of 17-19 g a.i./ha in a radius of 500 m around two villages. An.albimanus were monitored by light-traps and human bait collections at both treated villages, compared with two similar untreated villages, up to 9 nights posttreatment. Densities of female An.albimanus were significantly reduced in the sprayed villages for at least 8 or 9 nights. Further evaluation of barrier spraying is recommended to determine optimal pyrethroid formulations and applications rates, their impact on non-target fauna and efficacy against malaria transmission.
Assuntos
Anopheles , Insetos Vetores , Inseticidas , Malária/prevenção & controle , Controle de Mosquitos/métodos , Fenilcarbamatos , Análise de Variância , Animais , Bioensaio , Carbamatos , República Dominicana , Relação Dose-Resposta a Droga , Feminino , Malation , Nitrilas , Permetrina , PiretrinasRESUMO
Determinations on the penetration of ultra-low volume applied insecticide into dwellings was accomplished with a model house in Frederick, MD, USA, and native houses in Santo Domingo, Dominican Republic. Results from the model house tests show that aerosol droplets, with a volume median diameter of 4 microns, penetrated and remained suspended in low recesses of the building during the first 2 min after spraying. Similar results were found with tests in Santo Domingo, where man-made or natural obstructions were determined to be critical factors in aerosol penetration.
Assuntos
Aedes , Dengue/prevenção & controle , Habitação , Insetos Vetores , Malation , Aerossóis , Animais , República Dominicana , Humanos , Maryland , Controle de Mosquitos/métodosRESUMO
A field and laboratory study was conducted to determine some of the parameters relevant to malaria transmission by Anopheles mosquitoes in Dajabon Province, Dominican Republic. Although all 4 species occurring in the area, i.e., An. albimanus, An. crucians, An. grabhamii and An. vestitipennis, were included in the investigations, most of the work focused on the first and last named species because of their abundance. Gonotrophic cycles were determined to be 2.6 and 3.2 days for An. albimanus and An. vestitipennis, respectively. Mean parity rates for the 2 species were 37.3 and 20.7%, respectively, in outdoor samples. The human blood index, as determined by ELISA, was 0.08 for An. albimanus and 0.12 for An. vestitipennis. Only An. albimanus was confirmed positive for Plasmodium falciparum circumsporozoite protein, using ELISA. The vectorial capacity of An. albimanus was determined to be 0.019 and that of An. vestitipennis 0.005.
Assuntos
Anopheles , Insetos Vetores , Malária/transmissão , Animais , Anopheles/anatomia & histologia , República Dominicana , Ensaio de Imunoadsorção Enzimática , Comportamento Alimentar , Feminino , Humanos , Mordeduras e Picadas de Insetos/complicações , Oviposição , ParidadeRESUMO
The insecticide susceptibility of Aedes aegypti adults and larvae from Santo Domingo, Dominican Republic, was investigated using World Health Organization standard procedures. A field strain was more resistant to insecticides than a colony strain that originated from the same place. Larvae produced from ovitrap-collected eggs were resistant to temephos (78.2% mortality on exposure to 0.025 mg/liter). Mortality rates after exposure of adults to discriminating concentrations showed that wild populations were resistant to DDT, malathion, propoxur, permethrin and deltamethrin. The problem of resistance was considered serious enough to warrant consideration of control measures other than the use of chemicals.
Assuntos
Aedes , Inseticidas , Animais , DDT , República Dominicana , Resistência a Inseticidas , Larva , Malation , Nitrilas , Permetrina , Propoxur , Piretrinas , Especificidade da Espécie , TemefósRESUMO
Insecticide susceptibility of Anopheles albimanus and An. vestitipennis in Dajabon Province, Dominican Republic, was investigated. Only 74.3% of An. albimanus exposed to 4% DDT for 1 h died. The mortality in this species following exposure for 1 h to 0.25% permethrin was also 74.3%. However, this species was susceptible to malathion, fenitrothion and propoxur. The mortality obtained following exposure of An. vestitipennis to 4% DDT and 0.1% propoxur, both for 1 h, was 71% and 100%, respectively. However, the number of specimens exposed to propoxur was small.
Assuntos
Anopheles , Inseticidas , Animais , DDT , República Dominicana , Ecologia , Fenitrotion , Resistência a Inseticidas , Malation , Permetrina , Propoxur , Piretrinas , TemperaturaRESUMO
Field studies of Dajabon Province, Dominican Republic, revealed that Anopheles albimanus and An. vestitipennis were the most abundant anopheline species followed by An. crucians and An. grabhamii. Three of the species were collected as adults and larvae whereas An. grabhamii was found only in the adult stage. Perennial ponds and rice fields were the most important larval habitats. The anophelines were predominantly exophilic and exophagic; however, outdoor resting sites could not be identified. Large numbers of mosquitoes were collected from corrals at night and also by using an animal-baited net trap and UV light traps. Man-biting collections showed an early evening peak of biting activity by An. albimanus and An. vestitipennis. Only 23% and 13% of the bites by the 2 species, respectively, occurred indoors.
Assuntos
Anopheles/fisiologia , Animais , República Dominicana , Ecologia , Entomologia/métodos , Comportamento Alimentar , Humanos , Incidência , Mordeduras e Picadas de Insetos/epidemiologia , Larva , Vigilância da População , Especificidade da Espécie , SuínosRESUMO
Baseline field studies were conducted from April 1987 to July 1988 on Aedes aegypti in Santo Domingo, an endemic area for dengue fever. Premise, container and Breteau indices were measured in one treated area and 2 nearby control areas. These indices averaged 69.6, 46.3 and 142.1, respectively. The principal larval habitats of Ae. aegypti were 208-liter (55-gal) concrete-lined drums. The estimated daily adult production was approximately 60 per house. Adult mosquito populations were monitored using oviposition traps and by sweep net collections. There was no correlation between adult abundance and the larval indices. Monitoring the natural adult densities was more efficient for evaluating the impact of ULV malathion application than the use of standard bioassay procedures.
Assuntos
Aedes , Animais , Culex , República Dominicana , Ecologia , Entomologia/métodos , Feminino , Larva , Masculino , Densidade Demográfica , PupaRESUMO
Peripheral blood mononuclear cells (PBMC) obtained from four different primate species were tested for their respective ability to support the "in vitro" replication of the human immunodeficiency viruses, HIV-1, and HIV-2. PBMC of Cebus apella, patas (Erythrocebus patas), green (cercopithecus aethiops sabaeus) and rhesus monkeys (Macaca mulatta) were infected "in vitro" with either HIV-1 or HIV-2. Cultures were assayed weekly for particle-associated reverse transcriptase activity. Both viruses were found to be cytolytic for all these monkey's PBMC. Low levels of HIV-1 and HIV-2 infection were observed in Cebus cells. However, productive infection was only detected in HIV-2 infected rhesus PBMC. The capacity of HIV-2 to replicate in rhesus cells may provide a useful model for evaluating antiviral drugs and vaccines.
Assuntos
HIV-1/fisiologia , HIV-2/fisiologia , Haplorrinos/microbiologia , Leucócitos Mononucleares/microbiologia , Animais , Cebus/microbiologia , Sobrevivência Celular , Células Cultivadas , Chlorocebus aethiops/microbiologia , Erythrocebus patas/microbiologia , Leucócitos Mononucleares/enzimologia , Macaca mulatta/microbiologia , DNA Polimerase Dirigida por RNA/análise , Replicação ViralRESUMO
Efficacy of ground and aerial ultra-low volume (ULV) applications of 91% malathion at 438 ml/ha against Aedes aegypti in the Dominican Republic was evaluated using indoor collections, oviposition trapping and adult sentinel mortality rates. Ground compared to aerial ULV applications in this study were found to have a greater effect on Ae. aegypti when measured by the described sampling techniques. Neither application method provided the level of Ae. aegypti suppression believed necessary for control in the event of a dengue virus epidemic.