Tests of pyrethroid vaporising mats against Aedes aegypti (L.) (Diptera: Culicidae)

1977 ◽  
Vol 67 (4) ◽  
pp. 667-674 ◽  
Author(s):  
P. R. Chadwick ◽  
C. J. Lord

AbstractVaporising mats are used to volatilise small amounts of pyrethroid to prevent mosquito nuisance within houses. A small absorbent mat containing pyrethroid is placed on a 5- to 6-W electric heater. The mat surface temperature is about 125°C. Pyrethroid is released for several hours at a slowly diminishing rate. In tests, no evidence of degradation of bioallethrin was obtained. Vapour from mats inhibited biting by female Aedes aegypti (L.) and caused knockdown and kill. A commercial mat containing 88 mg allethrin was as effective as a mosquito coil containing 0·25% allethrin. In laboratory-made mats, 40 mg bioallethrin or 19 mg S-bioallethrin gave equal or better action than allethrin. Additives, such as piperonyl butoxide, mineral oil or antioxidant slightly reduced the rate of emission of pyrethroid and diminished the bite inhibitory and knockdown effects.

2014 ◽  
Vol 47 (5) ◽  
pp. 579-582 ◽  
Author(s):  
Boscolli Barbosa Pereira ◽  
Jean Ezequiel Limongi ◽  
Edimar Olegário de Campos Júnior ◽  
Denis Prudencio Luiz ◽  
Warwick Estevam Kerr

2002 ◽  
Vol 80 (10) ◽  
pp. 1126-1130 ◽  
Author(s):  
Claudia C López Lastra ◽  
Ann E Hajek ◽  
Richard A Humber

Nine species of entomopathogenic fungi were tested for viability after they had been stored with deionized water, mineral oil, or silica gel or frozen at –20 or –80°C. Species tested included members of the Hyphomycetes, Entomophthorales, Trichomycetes, and Oomycetes. The fungal cultures were maintained up to 1.5 years and were checked at 3, 6, 12, and 18 months. For all species evaluated, Paecilomyces fumosoroseus demonstrated the best results, surviving through 18 months when stored with water or mineral oil and when frozen at –80°C. For the majority of other fungal species tested, except the trichomycete Smittium culisetae and oomycete Leptolegnia chapmanii, freezing at –80°C was the best storage method and storage with silica gel was the worst. In addition to culture viability, infectivity against Aedes aegypti larvae was evaluated after 18 months of storage for L. chapmanii and S. culisetae. The simplest and least expensive methods, using water or mineral oil, were the only successful methods for maintaining viability and infectivity of L. chapmanii and S. culisetae.Key words: entomopathogenic fungi, preservation, storage, viability.


GEOgraphia ◽  
2021 ◽  
Vol 23 (50) ◽  
Author(s):  
Diego de Sousa Ribeiro Fonseca ◽  
Ricardo Alexandrino Garcia

O objetivo deste estudo foi determinar as áreas que têm tido maior propensão para ocorrência de infectados pela dengue na cidade Montes Claros-MG. A metodologia consistiu na aquisição de dados relativos ao número de infectados pela dengue, por bairros, nos anos 2015, 2016 e 2017; obtenção dos Índices Breteaures sobre infestação larvária pelo Aedes aegypti nos respectivos anos; uso de imagens de satélite para estimação da temperatura de superfície (TSE); aquisição de dados sobre elevação do terreno e renda familiar. Posteriormente, foi realizada a organização do banco de dados; emprego da análise descritiva; aplicação da regressão linear múltipla e da interpolação. O uso do modelo regressivo múltiplo, StepWise progressivo, para seleção das variáveis preditoras, com maior poder para explicação dos surtos de dengue ocorridos no período, mostrou-se eficiente, permitindo que fosse operacionalizada a co-krigagem, a qual trouxe as regiões sob maior probabilidade da ocorrência de infectados pela dengue. Genericamente, a infestação larvária pelo Aedes aegypti tem acontecido na porção oeste, enquanto a infecção pela dengue tem maior propensão na porção leste da cidade.Palavras-chave: infectados; infestação larvária; temperatura de superfície; altitude; renda domiciliar. ZONNING AREAS WITH THE BIGGEST PROPENTION TO SICK PEOPLE BY DENGUE IN THE MONTES CLAROS CITY (MG) USING SOCIO ENVIRONMENTAL VARIABLES AND GEOSTATISTICS Abstract: The objective of this work was to delimitation the determinats areas with the most propention to occurrence of sick peoples by dengue in the Montes Claros city, Minas Gerais. The methodology was consists in the acquisition of databases relateded at infects numbers by dengue, by neighborhoods, betwen the years 2015, 2016 and 2017; obtaining of Breteau Index about larval infestation by Aedes aegypti in the related years; use of satelities imagery to estimation of land surface temperature (LST); acquisition of databases about land elevation and familiar income. In the next time, was realize the organization of databases; employing the descriptive analysis; application of multiple linear regretion and interpolation of files. The use of regressive model, progressing StepWise, to selection of predictive variables, with more po explication power to disease outbreaks in the period, showed efficient, and this was permited the operationabilization of the co-kriging, which brought the regions with the more probability to dengue infectation. Overall, the larval infestation by the Aedes aegypti had happened on the west side, while the infectation by dengue have been more propention on the east side of the city, two portions in different economic situations, where the western part concentrates the population with the highest income. This factor denotes the fragility of the low-income population in terms of public health and their greater lack of strategic attention.Keywords: infected; larval infestation; land surface temperature; elevation; familiar income. ZONIFICACIÓN DE UBICACIONES CON MAYOR PROPENSIÓN PARA DENGUE DENTRO DE LA CIUDAD DE MONTES CLAROS (MG) A PARTIR DE VARIABLES SOCIOAMBIENTALES Y GEOSTATISTICAS Resumen: El objetivo de este estudio fue determinar las áreas que han sido más propensas a la ocurrencia de infectados por la dengue en la ciudad Montes Claros-MG. La metodología consistió en adquirir datos sobre el número de personas infectadas por dengue, en los barrios, en los años 2015, 2016 y 2017; obtención de los Índices de Breteaures sobre infestación larvaria por Aedes aegypti en los años respectivos; uso de imágenes de satélite para estimar la temperatura de la superficie (TS); adquisición de datos sobre elevación del terreno e ingresos familiares. Posteriormente, se organizó la base de datos; se hizo uso de análisis descriptivo; aplicación de interpolación y regresión lineal múltiple. El uso del modelo regresivo múltiple, progresivo StepWise, para seleccionar las variables predictoras, con mayor poder para explicar lo fenómeno de la dengue ocurridos en el período, resultó ser eficiente, permitiendo la operacionalización de la co-kriging, lo que llevó a las regiones bajo mayor probabilidad de personas infectadas con dengue. Generalmente, la infestación de larvas por el Aedes aegypti ha ocurrido en la parte occidental, mientras que la infección por la dengue es más probable en la parte oriental de la ciudad, dos partes en situaciones económicas diferentes, donde la parte occidental concentra la población de mayores ingresos. Este factor denota la fragilidad de la población de bajos ingresos en materia de salud pública y su mayor falta de atención estratégica.Palabras Clave: infectado; infestación de larvas; temperatura de la superficie; altitud; ingresos del hogar.


2011 ◽  
Vol 16 (4) ◽  
pp. 492-500 ◽  
Author(s):  
Georgina Bingham ◽  
Clare Strode ◽  
Lien Tran ◽  
Pham Thi Khoa ◽  
Helen Pates Jamet

1948 ◽  
Vol 39 (3) ◽  
pp. 387-397 ◽  
Author(s):  
Alec H. Parker

The reactions of Aëdes aegypti females to certain stimuli normally associated with the human surface body have been investigated. The apparatus used was such that the insects were unable to touch the source of stimulation. Attraction to the latter was indicated by the congregation of females in its vicinity.The following stimuli proved attractive: the intact palm of the hand; collected sweat at room temperature; moisture at room temperature; moisture at body-surface temperature. A warm surface at body-surface temperature produced no apparent effect, either of attraction or of repulsion.The four types of stimulus found to be attractive also had marked activating effects. The magnitude of these effects was much greater for the hand and warm moisture, than for cold sweat and cold moisture.Due allowance for the complication introduced by these differences in activation having been made, cold sweat appeared to be slightly, but significantly, more attractive than cold moisture. A reaction to olfactory stimuli is presumed to have been responsible for this. Such stimuli, however, are not considered to have been of much importance in comparison with warmth and moisture; moisture at body-surface temperature had very nearly, and possibly the same, attractive effect as the intact hand.The results are compared with those of other recent investigations, and the need for caution in applying them where conditions differ from those under which they were obtained is emphasised.


2021 ◽  
Vol 11 (5) ◽  
pp. 363-372
Author(s):  
Ali Habeeb Askar ◽  
Hazim Albedran ◽  
Endre Kovács ◽  
Károly Jármai

Surface temperature distribution on a tube is one of the main factors affecting the calculation of the heat transfer coefficient calculation. When an electric heater heats the tube, a magnetic flux is generated that affects the thermocouples readings; therefore, an efficient fitting technique is needed to represent these readings. This work proposes an interpolated spline method to mathematically represent experimental data of a thermal distribution on a tube with heat flux. Linear regression was compared with a double linear interpolation process with an optimization algorithm and cubic spline curve method on the proposed problem. The results show that the interpolated experimental data can highly improve the regression of the spline curve. Consequently, an interpolated spline curve gives better surface temperature distribution and better estimation for the average temperature. The interpolated points on spline segments are chosen by an optimization algorithm, which is particle swarm optimization, in a way that provides more minor errors.


1995 ◽  
Vol 198 (1) ◽  
pp. 167-174 ◽  
Author(s):  
M G Novak ◽  
J M Ribeiro ◽  
J G Hildebrand

A dense plexus of axons, immunoreactive to antisera against 5-hydroxytryptamine (5-HT, serotonin) and surrounding the proximal medial lobe of the salivary gland of adult female Aedes aegypti mosquitoes, was demonstrated by means of whole-mount fluorescence immunocytochemistry. This innervation originates in the stomatogastric nervous system. 5-HT-immunoreactive innervation is absent in male salivary glands, suggesting that 5-HT is involved in blood-feeding. Furthermore, female mosquitoes treated with the 5-HT-depleting agent alpha-methyltryptophan (AMTP) and then allowed to feed on a rat exhibited a significantly longer mean probing period and a lower blood-feeding success rate than did control mosquitoes. When female mosquitoes were experimentally induced to salivate into mineral oil, AMTP-treated individuals secreted significantly less saliva than did control mosquitoes. These samples of saliva also contained significantly lower concentrations of apyrase, an enzyme important in blood-feeding. Injection of 5-HT into both AMTP-treated and control mosquitoes elicited significant increases in the volume of secreted saliva and/or its apyrase content. We conclude that 5-HT plays an important role in the control of salivation in adult female A. aegypti.


Acta Tropica ◽  
2019 ◽  
Vol 189 ◽  
pp. 76-83 ◽  
Author(s):  
Monthathip Kongmee ◽  
Kanutcharee Thanispong ◽  
Sunaiyana Sathantriphop ◽  
Chutipong Sukkanon ◽  
Michael J. Bangs ◽  
...  

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