Temephos Resistance Status of Aedes aegypti Populations From Havana, Cuba.

Aedes aegypti chemical control remains an indispensable alternative to prevent dengue, Zika, and chikungunya outbreaks in Havana, Cuba. The city of Havana requires constant surveillance because of its bioecological characteristics that favor the proliferation of mosquito vectors of these viruses, which constitutes a high risk to the health of its inhabitants. The goal of this study was to determine the impact of the stopping of temephos applications during the 2 years of the COVID-19 pandemic on the level of susceptibility of Ae. aegypti in 5 municipalities of Havana, Cuba. Larval susceptibility was evaluated by bioassays as described by the World Health Organization. All Ae. aegypti populations tested showed high resistance to temephos. The National Control Program of Ae. aegypti in Cuba will need to promote insecticide rotation policies to prevent the evolution of temephos resistance in Havana.

Aedes albopictus (Skuse) dispersion in Havana City, Cuba, 1995-2018.

Various arboviruses are transmitted to humans by mosquitoes, particularly Aedes aegypti and Aedes albopictus, two invasive and frequently sympatric species. The objective of this study was to evaluate the dispersion and the behavior of Ae. albopictus in relation to houses and its association with other mosquitoes in the province of Havana, Cuba. All water-containing deposits in the houses or vacant lots in urban and peri­urban municipalities of the province of Havana were sampled during the two study periods: 1995-1999 and 2010-2018. The following patterns in the presence of Ae. albopictus in the study area were observed: a persistent absence of Ae. albopictus in one of the municipalities; a rapid dispersion in the second period, staring from the absence of vector in the first period, in tow other municipalities; and a sustained decrease in the dispersion of Ae.albopictus in two other municipalities. The peripheral municipalities noted the highest presence of Ae. albopictus, but few associations with other mosquitoes. However, overall, we found an increase in this association when comparing the period 2010-2018 with the first period. Ae. albopictus was present in 8% (2016) to 21.5% (2013) inside the houses with an average of 15%, which evidences an initial domiciliation of the species. The results obtained in this work show an initiation of domiciliation of Ae. albopictus in the urban area of the province of Havana. This is important to alert the National Control Program to strengthen the entomological monitoring of Ae. albopictus, and not only Ae. aegypti. The follow-up of this domiciliation is important to guide control efforts, knowing its role as a vector of different arboviruses.

High Aedes spp. larval indices in Kinshasa, Democratic Republic of Congo.

BACKGROUND: Dengue, yellow fever, chikungunya and Zika are among the most important emerging infectious vector-borne diseases worldwide. In the Democratic Republic of Congo (DRC), increases in cases of dengue and outbreaks of yellow fever and chikungunya have been reported since 2010. The main vectors of these arboviruses, Aedes aegypti and Aedes albopictus, have been reported in DRC, but there is a lack of detailed information on their presence and spread to guide disease control efforts. METHODS: In 2018, two cross-sectional surveys were conducted in Kinshasa province (DRC), one in the rainy (January/February) and one in the dry season (July). Four hundred houses were visited in each of the four selected communes (N'Djili, Mont Ngafula, Lingwala and Kalamu). Within the peri-domestic area of each household, searches were conducted for larval habitats, which were then surveyed for the presence of Aedes larvae and pupae. A subset of the immature specimens were reared to adults for morphological identification followed by DNA barcoding of the specimens to validate identifications. RESULTS: The most rural commune (Mont Ngafula) had the highest pupal index (number of Aedes spp. pupae per 100 inspected houses) at 246 (20) pupae/100 houses, and Breteau index (BI; number of containers positive for immature stages of Aedes spp. per 100 households) at 82.2 (19.5) positive containers/100 houses for the rainy (and dry) season, respectively. The BI was 21.5 (4.7), 36.7 (9.8) and 41.7 (7.5) in Kalamu, Lingwala and N'Djili in the rainy (and dry) season, respectively. The house index (number of houses positive for at least one container with immature stages of Aedes spp. per 100 inspected houses) was, on average, across all communes, 27.5% (7.6%); and the container index (number of containers positive for immature stages of Aedes spp. per 100 inspected containers) was 15.0% (10.0%) for the rainy (and dry) season, respectively. The vast majority of Aedes-positive containers were found outside the houses [adjusted odds ratio 27.4 (95% confidence interval 14.9-50.1)]. During the dry season, the most productive containers were the ones used for water storage, whereas in the rainy season rubbish and tires constituted key habitats. Both Ae. aegypti and Ae. albopictus were found. Anopheles larvae were found in different types of Aedes larval habitats, especially during the rainy season. CONCLUSIONS: In both surveys and in all communes, the larval indices (BI) were higher than the arbovirus transmission threshold values established by the World Health Organization. Management strategies for controlling Aedes in Kinshasa need to target the key types of containers for Aedes larvae, which are mainly located in outdoor spaces, for larval habitat destruction or reduction.

Melaleuca quinquenervia (Cav.) S.T. Blake (Myrtales: Myrtaceae): Natural alternative for mosquito control.

OBJECTIVE: To evaluate an essential oil with larvicide, adulticide and growth inhibitory activity against Aedes aegypti, Aedes albopictus and Culex quinquefasciatus mosquitoes, of medical importance. METHODS: Standardized methodology by WHO was used to determine the levels of susceptibility of mosquito larvae exposed to the essential oil. To evaluate the adulticide activity with the essential oil at different doses, bottles were impregnated according to the methodology CDC. To determine the development inhibitory activity of Melaleuca quinquenervia (M. quinquenervia) oil in three mosquito species, third instar larvae were exposed to the LC50 and LC90 dose (calculated for each population) of M. quinquenervia oil in glass containers with a capacity of 500 mL. After 24 h exposure, the dead larvae were discarded. The mortality of larvae and pupae were recorded on a daily basis. RESULTS: The calculated LC50 indicates an order of effectiveness of preferential oil for Culex quinquefasciatus (LC50 = 0.0021%), Aedes aegypti (LC50 = 0.0047%) and Aedes albopictus (LC50 = 0.0049%). CONCLUSIONS: The adulticide activity was achieved with impregnated bottles at 40 and 50 mg/mL with the three mosquitoes species. In larvae, a growth inhibition was detected when exposed to sublethal doses. The results indicate that M. quinquenervia is a plant with promising environmentally sustainable source for vector control.

Efecto de la temperatura y salinidad en la eclosión y supervivencia de Aedes aegypti (L) (Diptera: Culicidae) procedentes del occidente de México / Effect of temperature and salinity on the eclosion and survival of Aedes aegypti (L) (Diptera: Culicidae) from Western Mexico

Introducción: Aedes aegypti (L) (Diptera: Culicidae), es una especie cosmopolita y vector de arbovirosis. Las variaciones de la temperatura y salinidad del agua influyen en la eclosión y supervivencia de fases larvales. Objetivo: Evaluar el efecto de diferentes temperaturas y salinidades en la eclosión de huevos y la supervivencia de larvas, pupas y adultos bajo condiciones de laboratorio. Métodos: Se colectaron larvas de Ae. aegypti, de reservorios artificiales en la zona periurbana de Puerto Vallarta, Jalisco, México, y se mantuvieron hasta la fase adulta. Los huevos obtenidos se sometieron a ocho temperaturas (15, 17, 20, 25, 27, 30, 32 y 35 °C). Se colocaron 15 huevos por quintuplicado y se evaluó la eclosión durante 96 h. Se colocaron 100 huevos con agua ajustada a 0.3, 2, 5, 10, 15,18 y 22 ups y se evaluó la eclosión hasta las 96 h. Adicionalmente se utilizaron larvas del estadio IV, por quintuplicado, sometiéndose a las mismas salinidades y se evaluó la supervivencia hasta las 48 h. El efecto de la salinidad en la ovoposición de las hembras se llevó a cabo introduciendo recipientes con las mismas concentraciones salinas, dentro en las jaulas entomológicas. Resultados: Se registró el 100 por ciento de eclosión a las 24 y 48 h; la temperatura de 35° C no registró eclosión. Las salinidades de 22 y 18 ups, provocaron mortalidad del 100 por ciento a las 24 h. En la salinidad de 15 ups, sobrevivió el 50 por ciento. Las concentraciones de 2, 5 y 10 ups demostraron 100 por ciento de supervivencia hasta la fase de adulto. La supervivencia de larvas del estadio IV en los tratamientos 2, 5 y 10 fue del 100 por ciento y en 15,18 y 22 ups disminuyó a 50, 80 y 100 por ciento, respectivamente (p˂ 0,05). Las diferentes concentraciones salinas no afectaron significativamente la ovoposición. La eclosión solo se presentó en las concentraciones de 0,3; 2; 5 y 10 ups. Los huevos ovopositados en concentraciones de 15, 18 y 22 ups no eclosionaron hasta que fueron transferidos a agua dulce con porcentajes de eclosión de entre el 80 y 90 por ciento. Conclusiones: Los embriones de Ae. aegypti poseen una amplia plasticidad para soportar cambios drásticos de temperatura y salinidad. El control efectivo de sus poblaciones debe incluir la revisión de charcas o reservorios que contengan aguas salobres hasta 18 ups(AU)

Introduction: Aedes aegypti (L) (Diptera: Culicidae) is a cosmopolitan species and a vector of arboviruses. Variations in the temperature and salinity of the water affect eclosion and survival during the larval stages. Objective: Evaluate the effect of different temperatures and salinities on the eclosion of eggs and the survival of larvae, pupae and adults in laboratory conditions. Methods: Ae. aegypti larvae were collected from artificial reservoirs in a peri-urban area of Puerto Vallarta, Jalisco, Mexico, and maintained until the adult stage. The eggs obtained were subjected to eight temperatures (15, 17, 20, 25, 27, 30, 32 and 35 °C). Fifteen eggs were placed in quintuplicate and eclosion was evaluated for 96 h. One hundred eggs were placed with water adjusted to 0.3, 2, 5, 10, 15, 18 and 22 psu and eclosion was evaluated until 96 h. Additionally, stage IV larvae were used in quintuplicate, subjecting them to the same salinities and evaluating survival until 48 h. The effect of salinity on oviposition by females was determined by introducing containers with the same salinity into the entomological cages. Results: 100 percent eclosion was recorded at 24 and 48 h, whereas no eclosion occurred at a temperature of 35 °C. Salinities of 22 and 18 psu caused 100 percent mortality at 24 h, whereas 50 percent survived at a salinity of 15 psu. At concentrations of 2, 5 and 10 psu 100 percent of the larvae survived until the adult stage. Survival of stage IV larvae in treatments 2, 5 and 10 was 100%, whereas in 15, 18 and 22 psu it fell to 50, 80 and 100 percent, respectively (p˂ 0.05). The different salinities did not affect oviposition significantly. Eclosion only occurred at concentrations of 0.3, 2, 5 and 10 psu. Oviposited eggs at concentrations of 15, 18 and 22 psu did not eclose until they were transferred to fresh water, where eclosion percentages ranged between 80 percent and 90 percent. Conclusions: Ae. aegypti embryos have great plasticity to endure drastic changes in temperature and salinity. Effective control of their populations should include inspection of ponds and reservoirs containing brackish water of up to 18 psu(AU)

[Segregation of Aedes aegypti and Culex quinquefasciatus (Diptera: Culicidae) niche under laboratory conditions]. / Segregación de nicho de Aedes aegypti y Culex quinquefasciatus (Diptera: Culicidae) en condiciones de laboratorio.

INTRODUCTION: Aedes and Culex are two mosquito genuses of epidemiological importance, being Aedes aegypti and Culex quinquefasciatus the predominant ones in urban areas. It is common to find both of them associated in the same breeding sites where they share a lot of things despite the literature. OBJECTIVE: To determine if there is inter-specific competence between these two species when they co-exist in a single reservoir under lab conditions. METHODS: First staging larvae, which had been kept in the insect storage deposit of the Vector Control Department, were used. The three bioassays used 2 000 mL, 1 000 mL and 500 mL of dechlorinated water. The larvae were daily fed on with 0.7 g of fish flour; temperature was 26 degrees C +/- 2 degrees C. RESULTS: The larval cycle for Aedes aegypti was 6 days in crossbreds and in controls whereas it was 8 days for Culex quinquefasciatus, regardless of variation in the number of individuals of each species and in each bioassay. The larvae of each species completely developed since food was always provided and the living space remained the same. It should be noticed that the water was not totally translucent but no pollution indicators were observed. The sexual index for each species was determined after adult vectors emerged, with 1:1 ratio for both sexes approximately. CONCLUSIONS: Under lab conditions, these species did not compete one against the other for either food or living space and there was segregation of niche that favored their co-existence.

Plantas con actividad insecticida: una alternativa natural contra mosquitos / Insecticidal activity plants: A natural alternative against mosquitoes. Current status of the topic in the America´s region

Resumen El siguiente trabajo pretende reunir la información existente con respecto la evaluación de la actividad insecticida de plantas contra mosquitos realizados en la región de las Américas en los últimos veinte años. Se utilizó Pubmed Central, SCielo regional y BioOne y se acudió a buscadores como Google y Bing. Como criterio de inclusión se introdujeron las categorías: actividad larvicida, adulticida-repelente, ovicida e inhibidora del desarrollo de aceites esenciales y extractos de plantas en condiciones de laboratorio contra mosquitos en el área de las Américas en un período desde 1995-2015. La especie de mosquito más estudiada ha sido Ae aegypti seguido de Cx. quinquefascitus, Ae. albopictus, Cx. tarsalis, Cx. pipiens, An. albimanus. El país a la vanguardia en estudios sobre esta temática es Brasil seguido de Cuba México, Estados Unidos. Estados Unidos se destaca por la evaluación de productos comerciales registrados a base de plantas con actividad repelente. En 239 plantas se evaluó la actividad larvicida. El 64 % de los artículos revisados estudia este tipo de actividad con aceites esenciales. La repelencia es el acápite más estudiado después de la actividad larvicida, dentro de los que se destacan la evaluación de formulaciones comerciales con principios activos naturales. Con escasa representación, se encuentran los estudios sobre la actividad ovicida e inhibidora del desarrollo. Más de 85 plantas se evaluaron en forma de extractos y el extracto mas evaluado fue el etanólico seguido del metanólico y el acuoso.

Abstract The following paper aims to gather the existing information regarding the evaluation of the insecticidal activity of plants against mosquitoes made in the region of the Americas in the last twenty years. Pubmed Central, SCielo regional and BioOne were used and search engines such as Google and Bing were used. As an inclusion criterion, the categories were introduced: larvicidal, adulticidal-repellent, ovicidal activity and inhibitor of the development of essential oils and extracts of plants under conditions of Laboratory in the area of the Americas in a period from 1995-2015. The most studied mosquito species was Ae aegypti followed by Cx. quinquefascitus, Ae. albopictus and Cx tarsalis, Cx. pipiens, An. albimanus. The country at the forefront in studies on this subject is Brazil followed by Cuba Mexico, United States. The United States stands out by evaluating commercially registered herbal products with repellent activity. The larvicidal activity was evaluated in 239 plants. 64% of the reviewed articles study this type of activity with essential oils. The repellency is the most studied section after the larvicidal activity, among which the evaluation of commercial formulations with natural active principles. With little representation, there are studies on ovicidal and developmental inhibitory activity. More than 85 plants have been evaluated in the form of extracts and the most evaluated extract has been ethanolic followed by methanolic and aqueous.

[Chemical composition and lethal effect of essential oil from Pimenta racemosa (Myrtales: Myrtaceae) on Blatella germanica (Dictyoptera: Blattellidae)]. / Composición química y efecto letal del aceite esencial de Pimenta racemosa (Myrtales: Myrtaceae) sobre Blattella germanica (Dictyoptera: Blattellidae).

Gas chromatography test and Gas chromatography/mass spectrometry test allowed examining the essential oil from Pimenta racemosa leaves (Mill.) J.W. Moore (Myrtales: Myrtaceae). A total of 26 volatile compounds representing 99.5% of the whole composition were identified, being ternipen 4-ol and 1.8 cineol those having the largest portions. Lab bioassays were performed with 5 different oil doses on Blattella germanica. DL50, 15.55 and DL95 = 48.16% were estimated by a probit-log analysis as well as diagnostic dose of 2 microg/insect of 50% oil that is recommended for field surveillance of the use of various formulations in insect control programs.

[Identification of breeding sites of Anopheles sp. during part of the dry season in Jigawa, Nigeria]. / Identificación de los sitios de cría de Anopheles sp. durante parte de la estación seca en el estado de Jigawa, Nigeria.

A study was conducted in the state of Jigawa, Republic of Nigeria, from November to December in the dry season, where malaria is one of the main morbidity and mortality causes particularly in under 5 years-old children and pregnant women. This state had two climate seasons: dry from October to May and rainy from June to September. A total of 112 water bodies were sampled and just 18 in nine local governments were positive to mosquitoes. Breeding sites for Anopheles were rice fields, small holes in land, animal footsteps, small ponds, flooded pasture fields and water treatment dam, among others, to amount to 10 sites. Contrary to what has always been reported about the presence of Anopheles in clean waters, they were also breeding in highly polluted waters containing human faeces and garbage and located in open sewers.

Aedes aegypti larval indices and risk for dengue epidemics.

We assessed in a case-control study the test-validity of Aedes larval indices for the 2000 Havana outbreak. "Cases" were blocks where a dengue fever patient lived during the outbreak. "Controls" were randomly sampled blocks. Before, during, and after the epidemic, we calculated Breteau index (BI) and house index at the area, neighborhood, and block level. We constructed receiver operating characteristic (ROC) curves to determine their performance as predictors of dengue transmission. We observed a pronounced effect of the level of measurement. The BI(max) (maximum block BI in a radius of 100 m) at 2-month intervals had an area under the ROC curve of 71%. At a cutoff of 4.0, it significantly (odds ratio 6.00, p<0.05) predicted transmission with 78% sensitivity and 63% specificity. Analysis of BI at the local level, with human-defined boundaries, could be introduced in control programs to identify neighborhoods at high risk for dengue transmission.

[Ecological factors linked to the presence of Aedes aegypti larvae in highly infested areas of Playa, a municipality belonging to Ciudad de La Habana, Cuba]. / Factores ecológicos asociados con la presencia de larvas de Aedes aegypti en zonas de alta infestación del municipio Playa, Ciudad de La Habana, Cuba.

OBJECTIVES: To identify local ecological factors that might have had an impact on the higher infestation rates by the vector mosquito Aedes aegypti seen in four urban health districts of Ciudad de La Habana, Cuba, and to determine the type of containers with the highest number of larvae. METHODS: This is a descriptive study that was carried out in four health areas (Docente, 28 de Enero, 26 de Julio, and 1. degrees de Enero) within Playa, a municipality belonging to Ciudad de La Habana, Cuba. These areas were chosen because of the persistent presence of the dengue vector throughout 2003. All buildings on the selected blocks were inspected between April 2004 and March 2005, and note was taken of existing water deposits (type, number, and location) and of surrounding ecological factors (existence of a patio and shade, the way tanks were covered, the presence of organic matter inside them, and the overall cleanliness of the dwelling). Using filtration, the mosquito larvae and pupae in each deposit were counted. Pupae were typified as to their taxonomic species under a stereoscopic microscope. RESULTS: The types of deposits where larvae and pupae of A. aegypti were most often found in all areas were low tanks and small artificial containers. In three of the study areas the greatest numbers of pupae were found in low tanks (88.6%, 100%, and 56.6%), 90.9% of which were uncovered or only partially covered. On the other hand, in the fourth study area small artificial deposits were the most commonly infested (85.7%). A correlation was noted between the number of deposits in infested houses and the presence of a patio (chi(2) = 29.59; P = 0.0001), partial shade (chi(2) = 4.108; P = 0.0001), shrubbery (chi(2) = 43.59; P = 0.0001) and trees (chi(2) = 101.459; P = 0.0001), as well as poor hygiene (chi(2) = 53.76; P = 0.0001). CONCLUSIONS: Artificial deposits, especially low tanks and small containers, are the most frequent breeding sites for A. aegypti and are therefore risk factors for infestation with this vector species. Uncovered tanks containing organic matter and located in the shade on the outside of homes were found to present the highest risk in this respect.

[Report of habitats used by Aedes aegypti in Havana City, Cuba]. / Reporte de hábitats utilizados por Aedes aegypti en Ciudad de la Habana, Cuba.

50 habitats used by Aedes aegypti in the urban environment of Havana City were reported. 66% corresponded to artificial deposits, of which 57.5% were classified as unuseful by the population. 14% were receptacles of domestic use, whereas 8% were natural breeding places. It calls the attention that 12% of the habitats were represented by pits, sewers and drainages that contain the so-called black waters; a factor that should be considered in the epidemiology of dengue in Cuba and that deserves a study of the ecological factors associated with the specie that may influence on this behavior. It is encouraged the community participation as a tool in the control of this dangerous vector.

Utilización de aceites esenciales de pinaceas endémicas como una alternativa en el control del Aedes aegypti / Use of essential oils from endemic pinaceae as an alternative for Aedes aegypti control

INTRODUCCIÓN: Pinus caribaea y Pinus tropicalis son especies de plantas endémicas de Cuba y en su composición química presentan estructuras que se reportan en otras especies de plantas con fuerte actividad insecticida. OBJETIVO: evaluar el efecto larvicida de dos Pinaceas y sus derivados (aceites de trementina) en, Aedes aegypti, además de determinar el efecto ovicida de estos últimos en huevos de esta especie. MÉTODOS: se utilizó una cepa susceptible de referencia Rockefeller, suministrada por el Centro de Control de Enfermedades de San Juan de Puerto Rico y los bioensayos se realizaron según metodología de la Organización Mundial de la Salud para determinar resistencia y(o) susceptibilidad a insecticidas en mosquitos. El aceite de Pinus tropicalis fue obtenido por hidrodestilación y el aceite de Pinus caribaea se obtuvo por arrastre al vapor. El aceite de trementina (AT01) fue obtenido destilando la resina de pinos y una parte de este fue sometido a un tratamiento fotoquímico (AT02) de izomerización del a-pineno y b-pineno como componentes mayoritarios. RESULTADOS: el aceite de P. tropicalis mostró una concentración letal CL50= 42 mg/L y una CL95= 57 mg/L, y para P. caribaea la CL50= 51 mg/L y CL95= 181 mg/L. Los 2 aceites de trementina utilizados AT01 y AT02 mostraron alta acción larvicida al obtenerse las CL50 más bajas de este estudio (21,4 mg/L y 23,9 mg/L). El mayor efecto ovicida se mostró con la dosis diagnóstico del aceite de trementina AT02, con 94 % de no eclosión. CONCLUSIONES: los aceites foliales y sus derivados son candidatos para el control de esta especie de insecto, tanto por actividad insecticida como por su factibilidad, extracción y escalado.

INTRODUCTION: Pinus caribaea and Pinus tropicalis are endemic plants of Cuba and their chemical composition exhibits structures similar to those reported in other plant species with strong insecticidal action. OBJECTIVE: to evaluate the larvicidal effect of two pinaceae and their derivatives (turpentine oils) on Aedes aegypti in addition to determine the ovicidal effect of the latter on this species' eggs. METHODS: a reference susceptible strain called Rockefeller supplied by the Center of Disease Control in San Juan, Porto Rico was the choice whereas bioassays were conducted according to the World Health Organization methodology to ascertain resistance and (or) susceptibility of mosquitoes to insecticides. Water distillation allowed obtaining Pinus tropicalis oil and vapour dragging. Turpentine oil (AT01) was obtained by distilling pine resin and one part of it (AT02) underwent photochemical treatment of izomerization of a-pinen y b-pinen as main components. RESULTS: P. tropicalis showed lethal concentration LC50= 42 mg/L and LC95= 57 mg/L, and for P. caribaea, LC50= 51 mg/L and LC95= 181 mg/L. The two turpentine oils AT01 and AT02 exhibited high larvicidal action since they recorded the lowest LC50 of this study (21,4 mg/L and 23,9 mg/L). The greatest ovicidal effect went to diagnostic dose of AT02 turpentine oil, with 94% of hatching-deterrent action. CONCLUSIONS: leaf oils and their derivatives are candidates for the control of this species, because of their insecticidal action and also their feasibility, extraction and scaling.

Actividad insecticida de 3 aceites esenciales de plantas en Musca domestica (Diptera: Muscidae) / Insecticidal activity of 3 essential oils from plants on Musca domestica (Diptera: Muscidae)

Introducción: Musca domestica se transforma en vectores mecánicos de diversas enfermedades, transportando diferentes microorganismos patógenos en su morfología externa y en su tracto digestivo. Son numerosos los métodos utilizados para el control de esta especie con insecticidas químicos, tanto adulticidas como larvicidas, a los cuales se ha reportado resistencia. Objetivo: evaluar la acción insecticida de 3 extractos de aceites esenciales aislados de plantas sobre Musca domestica y obtener las dosis diagnóstico respectivas. Métodos: se utilizaron aceites esenciales de las especies botánicas Eugenia melanadenia (Myrtales: Myrtacea); Psidium rotundatum Griseg (Myrtales: Myrtacea) y Piper aduncum (Piperales: Piperacea) en la determinación de actividad insecticida potencial. Los bioensayos de laboratorio se desarrollaron utilizando una cepa procedente de una localidad rural nombrada Bentre. Se prepararon varias concentraciones de cada aceite para evaluar la mortalidades entre 10 y 100 por ciento, aplicando 1 µL en el tórax, según metodología de la OMS para pruebas de susceptibilidad a insecticidas. Resultados: para Eugenia melanadenia se obtuvieron valores de LD50= 0,21 por ciento y LD95= 1,33 por ciento, y una línea de regresión y= 4,82 + 2,05x. Los valores de las dosis letales (LD50 y LD95) para el aceite de Psidium rotundatum correspondieron a 0,18 y 2,4 por ciento, respectivamente, la ecuación de la recta resultó y= 4,92 + 1,49x. El aceite de Piper aduncum mostró LD50= 0, 04 por ciento y LD95= 0,33 por ciento y su ecuación y= 5,19 + 2,10x. Conclusiones: se comprobó la acción insecticida de estos aceites sobre hembras adultas de M. domestica. Se estimaron las dosis diagnóstico para Eugenia melanadenia (2 µg/insecto a 2,88 por ciento); Psidium rotundatum (2 µg/insecto a 7 por ciento) y Piper aduncum (2 µg/insecto a 0,6 por ciento) para su utilización, como método alternativo de control, en la vigilancia de poblaciones adultas de Musca domestica.

Background: musca domestica turns into vectors of several diseases by transporting different pathogenic microorganisms in its external morphology and digestive tract. A number of methods has been used to control this species by means of chemical insecticides both adulticides and larvicides, to which resistance has been reported. Objectives: to evaluate the insecticidal action of 3 essential oil extracts from plants on Musca domestica and to obtain the respective diagnostic doses. Methods: essential oils from Eugenia melanadenia (Myrtales: Myrtacea); Psidium rotundatum Griseg (Myrtales: Myrtacea) y Piper aduncum (Piperales: Piperacea) were used to determine the potential insecticidal action. The lab bioassays used a strain from a rural area named Bentre. Several concentrations of each of these oils were prepared to evaluate mortality from 10 to 100 percent, by applying 1 µL on Musca domestica thorax according to WHO methodology for insecticide susceptibility tests. Results: Lethal dose values for Eugenia melanadenia were LD50= 0.21 percent and LD95= 1.33 percent, being the regression line y= 4.82 + 2.05x. Psidium rotundatum oil had LD50= 0.18 and LD95= 2.4 percent and its line equation y was 4.92 + 1.49x. Piper aduncum oil showed LD50= 0.04 percent and LD95= 0.33 percent and its line equation y= 5.19 + 2.10x. Conclusions: the insecticidal action of these essential oils on M. domestica adult females was confirmed. Diagnostic doses for Eugenia melanadenia (2 µg/insect at 2.88 percent); Psidium rotundatum (2 µg/insect at 7 percent) and Piper aduncum (2 µg / insect at 0.6 percent) were estimated to be used as alternative controlling method in the surveillance of adult Musca domestica populations.

Comportamiento estacional y temporal de Aedes aegypti y Aedes albopictus en La Habana, Cuba / Seasonal and spatial behaviour of Aedes aegypti and Aedes albopictus in the City of Havana, Cuba

Objetivos: por causa de la permanencia de Aedes albopictus en el ecosistema urbano y periurbano de varios municipios, después de su introducción en Cuba en 1995, así como la presencia de poblaciones residuales de Aedes aegypti, se evaluó el comportamiento temporal y espacial de ambas especies en un municipio de Ciudad de La Habana. Métodos: se realizó la inspección de todos los locales del municipio Lisa durante enero-diciembre de 2006, se revisó todo tipo de depósitos con agua así como los criaderos naturales y las larvitrampas, dispositivo utilizado en la vigilancia del vector del dengue. Resultados: se demostró la plasticidad ecológica de Aedes aegypti destacándose su presencia en los tanques bajos y las latas, mientras que Aedes albopictus prevaleció en las latas y las gomas. El mayor número de recipientes positivos para ambas especies se encontró en los meses julio-septiembre, perteneciente a la estación lluviosa en Cuba. Se evidenció una distribución alopátrica entre ambas especies; porque a pesar de estar Aedes aegypti distribuido en todo el municipio, su presencia fue menor en las áreas rurales donde predominó Aedes albopictus; aunque este último se mantuvo durante todo el año con baja positividad en los recipientes. Conclusiones: a pesar de las actividades directas de control contra Aedes aegypti que se desarrollan en Cuba de manera permanente, las cuales hacen que prevalezcan bajas densidades de la especie, Aedes albopictus no la ha desplazado de sus sitios de cría habituales.

Objectives: Because of the permanence of Aedes albopictus in the urban and peri-urban ecosystems of various municipalities after the introduction of this vector in Cuba in 1995, as well as the presence of residual populations of Aedes aegypti, seasonal and spatial behaviour of both species was evaluated in a municipality of the City of Havana. Methods: All the facilities located in Lisa municipality were inspected from January to December 2006 in which all kinds of water storage containers as well as natural breeding sites and larvitraps, a device for dengue vector surveillance, were surveyed. Results: The ecological plasticity of Aedes aegypti was demonstrated, being mainly present in water storage tanks indoors and opened cans whereas Aedes albopictus prevailed in opened cans and water-filled tyres. The highest number of containers positive to both species was found from July to September during the rainy season in Cuba. In spite of the fact that Aedes aegypti was spread throughout the municipality, it was less predominant in rural areas than Aedes albopictus which in turn was less prevalent in containers. Conclusions: Although direct control actions against Aedes aegypti are permanently taken in Cuba, which leads to lower population densities of the species, Aedes albopictus has not been able to move the former away from its regular breeding sites.

Distribución y talla del adulto de Aedes aegypti asociado con los sitios de cría / Distribution and size of adult Aedes aegypti associated with the breeding sites

Introducción: Hoy día se realizan estudios ecológicos con el fin de buscar nuevas estrategias para el control de Aedes aegypti. Objetivos: agrupar los sitios de cría de Ae. aegypti en categorías y determinar el factor de riesgo de estas, establecer la talla de las hembras provenientes de pupas colectadas en el terreno, y conocer sobre la distribución del vector. Métodos: el trabajo se desarrolló en el municipio Playa. Se realizó la inspección de los locales y recipientes de donde se extrajeron las pupas para determinar la talla de las hembras emergidas. Resultados: se clasificaron los depósitos en 5 categorías: depósitos de almacenamiento de agua, depósitos artificiales abandonados en los patios, bebederos de animales, criaderos naturales y gomas. Se revisaron 2 506 locales, de los cuales 57 (2,27 por ciento) resultaron positivos al mosquito para un índice casa de 2,27, un índice de recipiente de 0,53 e índice de Breteau de 2,79. Los mayores valores promedio de longitud del ala de un total de 332 hembras y los mayores valores de factor de riesgo se encontraron en bebederos de animales y gomas con (3,07 ± 0,104 y 3,31 ± 0,95 mm) para un promedio de 2,95 ± 0,25 mm y 2,15 y 5,31, respectivamente. No se encontró diferencia significativa (ANOVA test p= 0,09) al compararse los valores de longitud del ala procedentes de las diferentes categorías de depósitos. Conclusiones: las hembras de Aedes aegypti mostraron variabilidad en su talla. Se encontró este vector distribuido en toda el área estudiada.

Introduction: At present, environmental studies are conducted to find new strategies for the control of Aedes aegypti. Objectives: To classify Aedes aegypti breeding sites into various categories and to determine their risk factors; to determine the size of females from pupas collected in situ and to learn about the vector distribution. Methods: this research work was carried out in Playa municipality. All the premises and water containers were inspected from where the pupas were taken to determine the size of emerged females. Results: Containers were classified into 5 categories: water storage containers, artificial containers left in house yards, troughs for animals, natural breeding sites and tyres. Two thousand five hundred and six premises were visited and inspected and 57 of them (2.27 percent) were positive to the mosquito for a index per house of 2.27; a container index of 0.53 and Breteau´s index of 2.79. The highest average measures in wing length of 332 females and the highest risk factor values were found in troughs for animals and tyres (3.07 ± 0.104 y 3.31 ± 0.95 mm) for an average of 2.95 ± 0.25 mm, and 2.15 and 5.31 respectively. No significant difference was found (ANOVA test, p= 0.09) when comparing the female wing length measurements gathered from the different container categories. Conclusions: Aedes aegypti females showed variable sizes. This vector was spread all over the studied area.

Actividad insecticida de aceites esenciales de plantas en larvas de Aedes aegypti (Diptera: Culicidae) / Insecticidal effect of essential oils from plants in Aedes aegypti larvae (Diptera: Culicidae)

Introducción: la búsqueda de nuevas alternativas y compuestos ambientalmente inocuos y que generen mínima resistencia, como los productos naturales y metabolitos de origen vegetal, constituye una importante línea de investigación en el control integrado de plagas y vectores. Objetivos: evaluar la acción insecticida de aceites esenciales de las plantas Curcuma longa, Melaleuca leucadendron, Artemisia abrotanum en Aedes aegypti. Métodos: para los bioensayos se utilizó una cepa de Aedes aegypti de referencia susceptible a insecticidas y estabilizada en el laboratorio nombrada Rockfeller. Los bioensayos se realizaron según la metodología de la OMS. Resultados: se obtuvieron las dosificaciones y mortalidades obtenidas para el aceite de Curcuma longa. Resultaron la CL50= 0,0025 por ciento(concentración letal que provoca 50 por ciento de mortalidad) y la CL95= 0,0044 por ciento (concentración letal que provoca 95 por ciento de mortalidad) y su línea de regresión Y= 5,56 + 6,60X. Para Melaleuca leucadendron resultó ser CL50= 0,0041 por ciento y la CL95= 0,0051 por ciento y la ecuación de su recta fue Y= 5,20 + 13,90X. El aceite de Artemisia abrotamum mostró una CL50= 0,0193 por ciento y la CL95= 0,0272 por ciento y su línea de regresión fue Y= 5,22 + 11,19X. Conclusiones: con este estudio se comprobó la acción insecticida de estos aceites en larvas de Ae. aegypti, por lo que se recomienda una dosis diagnóstico para Curcuma longa de 113 mg/L= 0,0113 por ciento, para Melaleuca leucadendron una dosis diagnóstico de 120 mg/L= 0,0120 por ciento y para Artemisia abrotamum 620 mg/L= 0,062 por ciento.

Introduction: The search for new alternatives and environmentally-friendly compounds that generate minimal resistance such as natural products and metabolites of vegetal origin constitutes an important research line included in the comprehensive management of plagues and vectors. Objective: To evaluate the insecticidal activity of essential oils from Curcuma longa, Melaleuca leucadendron, Artemisia abrotanum against Aedes aegypti mosquitoes. Methods: An Aedes aegypti reference strain, susceptible to insecticides and stabilized at the laboratory, was used for the bioassays. It was known as Rockefeller. The bioassays were performed following the WHO methodology. Results: Dosing and mortality indexes were obtained for the three essential oils. For Curcuma longa oil, LC50= 0.0025 (lethal concentration that causes 50 percent mortality), LC95= 0.0044 percent (lethal concentration that causes 95 percent mortality) and regression line Y= 5.56 + 6.60X. For Melaleuca leucadendron oil, LC50= 0.0041 percent, LC95= 0.0051 percent and the regression line was Y= 5.20 + 13.90X. Artemisia abrotamun oil showed LC50= 0.0193 percent, LC95m= 0.0272 percent and the regression line was Y= 5.22 + 11.19X. Conclusions: This study verified the insecticidal action of these oils on Aedes aegypti larvae and recommended diagnosis doses of 113 mg/L= 0.0113 percet for Curcuma longa, 120 mg/L= 0.0120 percent for Melaleuca leucadendron, and 620mg/L= 0.062 percent for Artemisia abrotamum.

Factores de riesgo de infestación pupal con Aedes aegypti dependientes de la comunidad en un municipio de Ciudad de La Habana / Risk factors of pupal infestation with community-based Aedes aegypti in a municipality of Havana City

Se identificaron los factores de riesgo de infestación pupal de Aedes aegypti dependientes de la comunidad en 4 áreas de salud del municipio Playa, ubicado en la zona urbana de Ciudad de La Habana. Los depósitos de mayor positividad al vector del dengue correspondieron a los depósitos artificiales y tanques bajos. Se comprobó que 99,03 por ciento de los locales visitados contenían al menos un depósito con agua, y que las 4 áreas presentaron un comportamiento muy similar en la proporción de tanques por locales, porque en todas la frecuencia de agua fue en días alternos, por lo que la diferencia en la positividad se debió a otros factores no ligados al abasto de este líquido. De los depósitos positivos, 87,17 por ciento se ubicó en los patios de los locales y 91,3 por ciento de los tanques bajos positivos se halló sin tapas o parcialmente tapados. Se encontró que en la positividad de los depósitos al vector del dengue solo 8,7 por ciento no depende de la población, por lo que de existir una participación activa de la comunidad dirigida al tapado de los tanques, el recambio de agua en los bebederos de animales y un buen saneamiento de los patios, se hubiera reducido drßsticamente la infestación pupal por Ae. aegypti en las áreas estudiadas.

The risk factors of pupal infestation with community-based Aedes aegypti were identified in four areas of Playa municipality, located in the urban zone of Havana City. The deposits with the highest positivity to the vector were the artificial ones and the low tanks. It was confirmed that 99.03 percent of the sites visited contained at least one deposit with water, and that 4 areas presented a very similar behaviour in ratio of tanks per site, since in all of them the water was supplied every other day. That is why the difference in the positivity was not due to factors related to the water supply. Of the positive deposits, 87.17 percent were located in backyards, and 91.3 percent of the positive low tanks had no cover, or were partially covered. It was found that in the positivity of the deposits to the dengue vector, only 8.7 percent were non-community dependent. If there had had an active participation of the community directed to cover the tanks, to change the water in the water troughs, and to clean the backyards, the pupal infestation due to Aedes aegypti would have drastically increased in the studied areas

Composición química y efecto letal del aceite esencial de Pimenta racemosa (Myrtales: Myrtaceae) sobre Blattella germanica (Dictyoptera: Blattellidae) / Chemical composition and lethal effect of essential oil from Pimenta racemosa (Myrtales: Myrtaceae) on Blatella germanica (Dictyoptera: Blattellidae

Se examinó mediante un análisis GC y GC-MS (cromatografía gaseosa-espectrometría de masa), el aceite esencial extraído de hojas de Pimenta racemosa (Mill.) J.W. Moore (Myrtales: Myrtaceae). Se identificaron un total de 26 compuestos volátiles que representaron 99,5 por ciento de la composición total; los de mayor proporción resultaron el terpinen-4-ol y 1,8-cineol. Se realizaron bioensayos al nivel de laboratorio con 5 dosificaciones de este aceite sobre la cucaracha Blattella germanica, se encontraron valores de DL50= 15,55 por ciento y DL95= 48,16 por ciento mediante un análisis probit-log, así como una dosis diagnóstica de 2 µg/insecto del aceite a 50 por ciento, que se propone para la vigilancia en el terreno del uso de formulaciones en programas de lucha contra este insecto.

Gas chromatography test and Gas chromatography/mass spectrometry test allowed examining the essential oil from Pimenta racemosa leaves (Mill.) J.W. Moore (Myrtales: Myrtaceae). A total of 26 volatile compounds representing 99.5 percent of the whole composition were identified, being ternipen 4-ol and 1,8 cineol those having the largest portions. Lab bioassays were performed with 5 different oil doses on Blattella germanica. DL50=15.55 and DL95=48.16 percent were estimated by a probit-log analysis as well as diagnostic dose of 2 µg/insect of 50 percent oil that is recommended for field surveillance of the use of various formulations in insect control programs.

Bebederos de animales: depósitos a tener en cuenta por el Programa de Control de Aedes aegypti en áreas urbanas de Ciudad de La Habana, Cuba / Drinking troughs for animals: containers that should be taken into account for the Aedes aegypti Control Program in urban areas of the City of Havana, Cuba

Se hizo un estudio de la influencia de los bebederos de animales en la infestación de Aedes aegypti en el área urbana del municipio Playa. En total se revisaron 700, reportándose 5 (0,71 %) positivos al vector del dengue, correspondiendo su totalidad a bebederos de perros. Se detectaron 32 pupas para un promedio de 6,4 por bebedero. No se encontraron diferencias significativas de la productividad pupal en los distintos depósitos positivos a Aedes aegypti durante el estudio (p> 0,05). Los bebederos se caracterizaron por estar preferiblemente a la sombra, en los patios de las viviendas y contenían abundante materia orgánica. Se resaltó la importancia de estos para el programa de control del vector, por las características de su ubicación que favorece la oviposición de las hembras, por no ser objetos de recambio diario de agua por la población y por su potenciabilidad de aportar adultos de gran talla, factor importante en la transmisión del virus del dengue.

A study of the effect of drinking troughs for animals over the infestation by Aedes aegypti in the urban area of Playa municipality was performed. Seven hundred drinking troughs were checked, but only 5 (0.71%) were positive to dengue vector. These five corresponded to drinking containers for dogs. Thirty two pupas were detected for an average of 6.4 per trough. There were no significant differences in pupal productivity among the drinking troughs positive to Aedes aegypti (p>0.05). The drinking troughs were mainly placed at shadowed sites, in the backyard of houses, and characterized by having abundant organic matter. This study underlined the importance of these drinking containers for the dengue vector control program because their above-mentioned location favors egg-laying by female insects, their water content is not daily changed by the population as it1. should be done, and because they can potentially provide large-sized adult vectors, which are an important factor in the transmission of the dengue virus.