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The current study describes the effects of sub-lethal concentrations and constituent compounds (citral and geranyl acetate) of Cymbopogon flexuosus essential oil (EO) on the development of Aedes aegypti. We treated eggs with 6, 18, or 30 mg L−1 and larvae with 3 or 6 mg L−1 of EO and its major compounds (citral and geranyl acetate). Citral and geranyl acetate were evaluated at 18, 30, and 42 mg L−1 and compared with commercial growth inhibitors (diflubenzuron and methoprene). We measured larval head diameter, siphon length, and larval length. Finally, we examined concentrations of molt hormone (MH) and juvenile hormone III (JH III) using high-performance liquid chromatography coupled to mass spectrometry. All geranyl acetate concentrations decreased egg hatching, while EO altered molting among larval instars and between larvae and pupae, with an increase in the larval length (3 mg L−1: 6 ± 0.0 mm; 6 mg L−1: 6 ± 0.7 mm) and head width (3 mg L−1: 0.8 ± 0 mm; 6 mg L−1: 0.8 ± 0.0 mm) compared with the control group. We did not detect chromatographic signals of MH and JH III in larvae treated with C. flexuosus EO or their major compounds. The sub-lethal concentrations C. flexuosus EO caused a similar effect to diflubenzuron, namely decreased hormone concentrations, an extended larval period, and death.

Mosquito borne diseases are on the rise because of their fast spread worldwide and the lack of effective treatments. Here we are focusing on the development of a novel anti-malarial and virucidal agent with biocidal effects also on its vectors. We have synthesized a new quinoline (4,7-dichloroquinoline) derivative which showed significant larvicidal and pupicidal properties against a malarial and a dengue vector and a lethal toxicity ranging from 4.408 µM/mL (first instar larvae) to 7.958 µM/mL (pupal populations) for Anopheles stephensi and 5.016 µM/mL (larva 1) to 10.669 µM/mL (pupae) for Aedes aegypti. In-vitro antiplasmodial efficacy of 4,7-dichloroquinoline revealed a significant growth inhibition of both sensitive strains of Plasmodium falciparum with IC50 values of 6.7 nM (CQ-s) and 8.5 nM (CQ-r). Chloroquine IC50 values, as control, were 23 nM (CQ-s), and 27.5 nM (CQ-r). In vivo antiplasmodial studies with P. falciparum infected mice showed an effect of 4,7-dichloroquinoline compared to chloroquine. The quinoline compound showed significant activity against the viral pathogen serotype 2 (DENV-2). In vitro conditions and the purified quinoline exhibited insignificant toxicity on the host system up to 100 µM/mL. Overall, 4,7-dichloroquinoline could provide a good anti-vectorial and anti-malarial agent.

The aim of this research study was to understand the mechanism of action of Salvia officinalis (Lamiaceae) essential oil (EO) on Aedes aegypti larvae. We evaluated the effect on DNA damage, acetylcholinesterase (AChE) inhibition and mitochondrial enzymatic alterations. The major components were analyzed in silico using OSIRIS and Molispiration free software. Aedes aegypti DNA was extracted from mosquito larvae between third (L3) and fourth (L4) instars to determine the DNA fragmentation or degradation at S. officinalis EO lethal concentrations (LC10, LC20, LC50, and LC90). DNA integrity was assessed in both LCs in larvae treated for 24 h and in larvae homogenized with EO; we also assessed purified DNA larvae by a densitometric analysis. The AChE inhibition was quantified in protein larvae L3-L4 following Ellman's method and the enzymatic activities related to the mitochondrial respiratory chain of mitochondrial proteins was estimated by spectrophotometry. In silico analysis of 1,8-cineol and of α-thujone, major EO components, showed that they were highly permeable in biological membranes without mutagenic risks. Alterations in the integrity of DNA were observed in larvae exposed and homogenized with S. officinalis EO. The EO induced an AChE inhibition of 37 ± 2.6% to IC50. On the other hand, mitochondrial bioenergetics suggest that EO inhibits electrons entry to the respiratory chain, via Complex II. AChE activity alteration causes mortality of individuals, by blocking the insect cholinergic functions. These results indicate that EO affects the integrity of DNA, the mitochondrial respiration chain and the AChE activity.

The current study describes the effects of sub-lethal concentrations and constituent compounds (citral and geranyl acetate) ofCymbopogon flexuosusessential oil (EO) on the development ofAedes aegypti(L.) eggs and larvae. To demonstrate the ovicidal activity of EO, we treated embryonated eggs with 6, 18, and 30 mg.L-1and larvae with 3 and 6 mg.L-1EO concentrations. Citral and geranyl acetate were evaluated at 18, 30, and 42 mg.L-1and compared with commercial growth inhibitors (diflubenzuron and methoprene) at 3 and 6 mg.L-1concentrations. For each treatment, we measured larval head diameter, siphon length, and body length. To complement the morphological analysis, we examined concentrations of moult hormone (MH) and juvenile hormone III (JH III) using high-performance liquid chromatography (HPLC) coupled to mass spectrometry. The EO decreased egg hatching at all concentrations: 6 mg.L-1in 45.3%; 18 mg.L-1in 23.3%, and 30 mg.L-1in 34.6%. EO also altered molting among larval instars and between larvae and pupae, with an increase in the length (3 mg.L-1: 6 ± 0.0 mm; 6 mg.L-1: 6 ± 0.7 mm) and head width (3 mg.L-1: 0.8 ± 0 mm; 6 mg.L-1: 0.8 ± 0.0 mm) compared with the control group (length: 5.3 ± 0 mm; head width: 0.7 ± 0.0 mm). We did not detect chromatographic signals of MH and JH III in larvae treated withC. flexuosusEO or their major compounds. The sub-lethal concentrationsC. flexuosusEO caused a similar effect to diflubenzuron, decreasing hormone concentration, extending the larval period, and death.

To generate an impact on the suppression of diseases such as Zika, it is necessary that vector control activities converge in a smart system exclusive for this goal. Chemical compounds collected from natural sources could contribute to such a control system in a powerful way, because they contain multieffect molecules useful to design and develop future insecticides and repellents. Here, we present information focused on our understanding of the utility of molecules from natural sources to control mosquito populations, aiming to promote their use by those involved in the field of mosquito control. We aim to convey this information in a way that can be useful to both the specialist in the topic and those whose interest in the topic is to avoid the bites of urban mosquitoes like Aedes aegypti or Ae. albopictus.

In mosquitoes of medical importance, wing shape and size can vary with altitude, an aspect that can influence dispersion and, consequently, their vector capacity. Using geometric morphometry analysis, Aedes aegypti wing size and shape variation of males and females was studied in four altitudes in the second-smallest department in Colombia: 1.200 m (Tebaida), 1.400 m (Armenia), 1.500 m (Calarcá), and 1.700 m (Filandia). Wing shape in males (P < 0.001) and females (P < 0.001) was significantly different through the altitudinal gradient; in turn, wing size in males followed the altitudinal gradient (Males R2 = 0.04946, P = 0.0002), Females (R2 = 0.0011, P = 0.46). Wing allometry for males (P < 0.001) and females (P < 0.001) was significant. Likewise, the shape and size of the wings of males (P < 0.001) and females (P < 0.001) had significant fluctuating asymmetry. It is concluded that, in a small scale with an altitudinal variation of 500 meters, it is detected that the size and shape of the wings varied in A. aegypti, principal vector of dengue, chikungunya, and Zika. The fluctuating asymmetry is present in the individuals studied and could be associated with environmental effects caused by vector control campaigns present in some sampling locations.

Resumen Introducción: Las zonas urbanas tropicales favorecen la presencia de Aedes aegypti en el continente americano. Otros culícidos pueden compartir la misma área de distribución con este mosquito, lo cual justifica que se deban monitorear. Objetivo: Conocer la dinámica de oviposición de A. aegypti, evaluar su estado gonadotrófico y determinar taxonómicamente la presencia de otros culícidos en el área metropolitana de Bucaramanga. Metodología: Para este propósito fueron instaladas trampas de oviposición (N=960) cebadas con infusión de heno (10%) durante un año en cuatro localidades (Norte, Girón, Piedecuesta y Floridablanca). Las ovitrampas permanecieron instaladas durante cinco días en intradomicilio y peridomicilio, paralelamente se colectaron larvas en plantas como bromelias y depósitos de agua en cada lugar de colecta. En el mes de mayo de 2014 fueron capturadas con un aspirador eléctrico y trampas StegTrap hembras de A. aegypti y Cx. quinquefasciatus a las cuales se les estimó su estado gonadotrófico. Datos ambientales como precipitación y temperatura fueron correlacionados con índices de oviposición. Resultados: Se obtuvieron 25.254 huevos de A. aegypti (Girón 39,1%, Bucaramanga 36,8% Floridablanca 15,2% y Piedecuesta 8,9%) en general los índices de oviposición fueron mayores en peridomicilio con correlaciones positivas (> 0. 5) entre los índices NOP, NH e IPO en peridomicilio y IPO y IDH en intradomicilio con la precipitación y la humedad. En cuanto al estado gonotrófico se determinó que las hembras de A. aegypti presentaron hasta dos ciclos gonadotróficos en las áreas examinadas. En las colectas activas en peridomicilio se encontró, Culex spissipes, Culex quinquefasciatus, Limatus durhamii, Toxorhynchites spp y Wyeomyia davisi. Conclusión: A. aegypti fue presente en todas localidades y se reportan otros culícidos potenciales vectores en el área metropolitana. Abstract Introduction: Tropical urban areas favor the presence of Aedes aegypti in the American continent. Other mosquitoes can share the same geographic distribution with this mosquito, which justifies that they must be monitored. Objective: It is to know the dynamics of oviposition of A. aegypti, evaluate its gonadotrophic state and determine taxonomically the presence of other culicidae in the metropolitan area of Bucaramanga. Methodology: Oviposition traps (N = 960) were baited with hay infusion (10%) for one year in four locations (Norte, Girón, Piedecuesta and Floridablanca). The ovitraps were kept for five days indoors and outdoors, while larvae were collected in plants such as bromeliads and water reservoirs from each collecting site. In the month of May 2014, were captured with an electric aspirator and traps to catch females of A. aegypti and Culex quinquefasciatus to which were estimated their gonadotrophic state. Environmental data such as precipitation and temperature were correlated with the collected eggs and their oviposition indices. Results: 25,254 eggs of A. aegypti were obtained (39.1% Girón, 36.8% Bucaramanga, 15.2% Floridablanca and 8.9% Piedecuesta). In general, oviposition rates were higher outdoors. As for the gonotrophic state, it was detected that females of A. aegypti can have for over two gonadotrophs cycles. In the active catch outdoors were found Culex spp., Culex quinquefasciatus, Limatus durhamii, Toxorhynchites spp and Wyeomyia davisi. Conclusion: A. aegypti was present in all localities and other mosquitoes are reported in the metropolitan area.

espanolIntroduccion: Analogos del alcaloide girgensohnina, disenados y sintetizados para inhibir a la enzima acetilcolinesterasa, han presentado efecto insecticida sobre insectos vectores de enfermedades. Objetivo: Determinar la actividad insecticida de 12 analogos sinteticos de gingersohnina sobre ninfas del primer estadio de Triatoma dimidiata. Materiales y Metodos: Se tomo como referencia el protocolo de la OMS 2005. Ninfas del primer estadio de T. dimidiata fueron expuestas a los analogos por aplicacion topica y exposicion a superficies para determinar las dosis letales (DL50 y DL95) y verificar alteracion en la locomocion mediante el software Videomex V. Resultados: El analogo 6 presento la mayor actividad insecticida a las 72h con una mortalidad del 20,8% ± 3,57 para el tratamiento de topicacion 25% ± 0,00 para las superficies no porosas. Las dosis letales de la molecula 6 fueron: DL50 1036,8 ± 0,38 ng/insecto y DL95 3991,4 ± 0,50 ng/insecto respectivamente. Con respecto a la locomocion, el analogo indujo un comportamiento similar al insecticida comercial deltametrina. EnglishIntroduction: Analogs of the girgensohnine alkaloid, designed and synthesized to inhibit acetylcholinesterase enzyme, have presented an insecticidal effect on vectors insects of diseases. Objective: To determine the insecticidal activity of 12 synthetic analogs of gingersohnine in first stage nymphs of Triatoma dimidiata. Materials and methods: WHO protocol 2005, using exploratory doses, was used to determine the best molecule according to its mortality. First stage nymphs of T. dimidiata were exposed to different doses of the analogs by topical application and surface exposure. Lethal doses (LD50 and DL95) and alterations in locomotion using Videomex V software were determined. Results: Analog 6 presented the highest insecticidal activity at 72 h with a mortality of 20.8% ± 3.57 for topical treatment and 25%±0,0 for non-porous surfaces evaluation. Analog 6 lethal doses were LD50 1036.8 ± 0.38 ng/insecto and DL95 3991.4 ± 0.508 ng/insecto, respectively. With regard to locomotion, analogue 6 induced a similar behavior to that observed for commercial insecticide deltametrin.

Aedes aegypti is the principal vector of arboviral pathogens that may cause diseases as dengue fever, chikungunya and zika. The harmful environmental effects of commercial pesticides coalesced with the development of insecticide-resistant populations encourage the discovery and generation of new alternative products as a tool to reduce the incidence of vector-borne diseases. In this work, through the classic three component Strecker reaction of commercial benzaldehydes, cyclic secondary amines and KCN, a new series of nine α-amino nitriles, girgensohnine analogs, has been synthetized and screened for larvicide and adulticide properties against A. aegypti, one of the dominant vectors of dengue, chikungunya and zika in tropical and subtropical areas all over the world. Molecules 3 and 4 were identified as potential larvicidal agents with LC50 values of 50.55 and 69.59 ppm, respectively. Molecule 3 showed 100% of mortality after 2 h of treatment when a concentration of 30 ppm in adulticidal assays was evaluated. Additionally, in order to elucidate the mode of action of these molecules, their acetylcholinesterase (AChE) inhibitory properties were evaluated using the Ellman assay. It was found that the molecules possess a weak AChE inhibitory activity with IC50 values between 148.80 and 259.40 μM, indicating that AChE could not be a principal target for insecticide activity. Keywords: Arthropod-borne diseases, Girgensohnine analogs, Strecker reaction, Insecticidal activity, Vector control

Compounds having insecticidal activity can be used to control Aedes aegypti mosquitoes, a major worldwide vector, and several plants have a source of such molecules. A principal component analysis (PCA) was carried out to determine the criterion to select larvicidal metabolites. The insecticidal activity of seven selected metabolites by PCA was validated by determining its lethal concentrations 50 (LC50) by probit analysis. Six of the seven evaluated molecules presented LC50 values

In mosquitoes of medical importance, wing shape and size can vary with altitude, an aspect that can influence dispersion and, consequently, their vector capacity. Using geometric morphometry analysis, Aedes aegypti wing size and shape variation of males and females was studied in four altitudes in the second-smallest department in Colombia: 1,200 m (Tebaida), 1,400 m (Armenia), 1,500 m (Calarcá), and 1,700 m (Filandia). Wing shape in males (P < 0.001) and females (P < 0.001) was significantly different through the altitudinal gradient; in turn, wing size in males followed the altitudinal gradient males (R2 = 0.04946, P = 0.0002), females (R2 = 0.0011, P = 0.46). Wing allometry for males (P < 0.001) and females (P < 0.001) was significant. Likewise, the shape and size of the wings of males (P < 0.001) and females (P < 0.001) had significant fluctuating asymmetry. It is concluded that, in a small scale with an altitudinal variation of 500 meters, it is detected that the size and shape of the wings varied in A. aegypti, main vector the agents that cause dengue, chikungunya, and Zika. The fluctuating asymmetry is present in the individuals studied and could be associated with environmental effects caused by vector control campaigns present in some sampling locations.

We examined the pupicidal, adulticidal, repellent, and oviposition-deterrent activities of essential oils (EOs) from Lippia alba, L. origanoides, Eucalyptus citriodora, Cymbopogon citratus, Cymbopogon flexuosus, Citrus sinensis , Cananga odorata , Swinglea glutinosa, and Tagetes lucida plants against Aedes aegypti under laboratory conditions. Pupicidal and adulticidal activities were assessed at exploratory concentrations of 250, 310, and 390 parts per million (ppm); and 30, 300, and 1,000 ppm, respectively. The greatest pupicidal activity was exhibited at 390 ppm with a 24-h exposure by L. origanoides, and 390 ppm with a 48-h exposure by Citrus sinensis . Lippia origanoides killed all adult mosquitoes at 300 ppm after 120 min of exposure. Only L. origanoides and E. citriodora EOs, applied at 1,000 ppm to human skin, produced the greatest repellency (100%) to host-seeking Ae. aegypti after 2 min of exposure; the repellency decreased between 12% and 10% after 15 min. Complete oviposition deterrence by gravid Ae. aegypti was observed for E. citriodora EOs at 200 ppm with an oviposition activity index of -1.00. These results confirm that the EOs assessed in this study have insecticidal, repellent, and oviposition-deterrent activities against the dengue vector, Ae. aegypti.

Oils of Carapa guianensis and Copaifera spp. are well-known in the Amazonian region as natural insect repellents, and studies have reported their efficiency as larvicide against some mosquito species. However, toxicity persistence and effect on mosquito development have not yet been evaluated. Thus, the objective of this study was to evaluate the initial time of larvicidal activity, residual effect, and the effect of very low concentrations of these oils on Aedes aegypti. Different concentrations of the oils were used to evaluate the initial time of larval mortality and residual effect, as well as, the development of larvae, pupae, and adults. Results demonstrated that the lethal effect started mainly between the first 2 and 3 h of larvae exposure to oils, when using concentrations which ranged from 500 mg/L of C. guianensis and 90 mg/L of Copaifera sp. The toxic effect remained with total efficiency (100% mortality) until the sixth day for Copaifera sp. and 12th day for C. guianensis. When using sublethal dosages (ranging from 140 mg/L of C. guianensis to 26 mg/L of Copaifera sp.) mortality was observed after the larval molt. Also, imperfection of pupae and adult development and unsuccessful emergence of adults were observed. A product of botanical origin that could break the development of immature stage of mosquitoes and inhibit the emergence of adults should be essential in vector control. Thus, our results provide new information for a better understanding in using C. guianensis and Copaifera sp. oils with a potential to be used as a natural insecticide.

Bites from the recluse or brown spiders (genus Loxosceles) can cause necrotic lesions and systemic effects in humans throughout the world. In the state of Parana, Brazil, loxoscelism is considered a serious public health problem, and Loxosceles intermedia Mello-Leitao (Araneae: Sicariidae) is associated with the majority of reported accidents. In the present research we evaluated the susceptibility of L. intermedia to pyrethroid insecticides currently used for the control of spiders in both field and laboratory conditions. In laboratory tests, the most active pesticides in descending order were microencapsulated lambda-cyhalothrin (LC50 = 0.023 mg/kg), nonmicroencapsulated lambda-cyhalothrin (LC50 = 0.047 mg/kg), deltamethrin (LC50 = 0.26 mg/kg), and Cypermethrin (LC50 = 1.38 mg/kg). Cockroaches, Phoetalia circumvagans (Burmeister) (n = 30), killed with microencapsulated lambdacyalothrin, were offered to the spiders. L. intermedia fed on 63.3% of the dead cockroaches during the first 6 h of experiment; none of the spiders died during the subsequent 15 d. Microencapsulated lambdacyalothrin was chosen for application in two contiguous houses. The mean volume applied was 22.8 mg (AI) /m2. Dead spiders were found during all the inspections up to 60 d after the initial application. In total, 297 dead spiders were collected; 65.7% in the attic shared by the two homes, 10.8% inside the house that had most cracks and crevices sealed and 23.6% in the control house. The use of lambda-cyhalothrin-based products for L. intermedia control is discussed.

The choice for suitable places for female mosquitoes to lay eggs is a key-factor for the survival of immature stages (eggs and larvae). This knowledge stands out in importance concerning the control of disease vectors. The selection of a place for oviposition requires a set of chemical, visual, olfactory and tactile cues that interact with the female before laying eggs, helping the localization of adequate sites for oviposition. The present paper presents a bibliographic revision on the main aspects of semiochemicals in regard to mosquitoes' oviposition, aiding the comprehension of their mechanisms and estimation of their potential as a tool for the monitoring and control of the Culicidae. A seleção de locais adequados pelas fêmeas de mosquitos para depositarem seus ovos é um fator chave para a sobrevivência de seus imaturos (ovos e larvas). O conhecimento das relações ecológicas implicadas neste processo é de grande importância quando se refere a vetores de agentes patogênicos. A determinação do local de oviposição pelas fêmeas grávidas envolve uma rede de mensagens químicas, visuais, olfativas e táteis que facilitam a localização de lugares adequados para depositarem seus ovos. Neste trabalho é apresentada uma revisão bibliográfica dos principais aspectos relacionados com semioquímicos presentes na oviposição dos mosquitos auxiliando no entendimento dos mecanismos de atuação dos mesmos e potencializando a aplicação destes semioquímicos como uma possível ferramenta de monitoramento e controle de Culicidae.

Avaliou-se a abundância e agregação dos ovos de Aedes aegypti L. e Aedes albopictus Skuse em Cambé, Ibiporã, Jacarezinho, Maringá e Paranavaí, PR, utilizando-se armadilhas de oviposição. De 225 armadilhas instaladas, 100 registraram-se positivas para ovos. Coletaram-se 4140 ovos, demonstrando distribuição altamente agregada. Ambas as espécies foram encontradas em Cambé, Jacarezinho, Maringá e Paranavaí. Ae. albopictus não foi detectado em Ibiporã, porém onde esteve presente foi menos abundante. A relação entre sexos aproximou-se de 1:1, para Ae. aegypti. Na comparação dos números de adultos coletados entre as duas espécies, obteve-se correlação negativa nas amostras de Maringá e Cambé, o que foi atribuído à sazonalidade dessas populações. A coexistência dessas espécies indica que elas estão sobre pressão dos programas de controle, sendo, portanto necessárias avaliações específicas. The abundance and aggregation of eggs of Aedes aegypti L. and Aedes albopictus Skuse was evaluated in the municipalities of Cambé, Ibiporã, Jacarezinho, Maringá and Paranavaí, in the State of Paraná, Brazil by means of oviposition traps. Of the 225 installed traps, 100 were registered as positive for eggs; 4140 eggs were collected, thus demonstrating an highly aggregate distribution. Both species were registered in Cambé, Jacarezinho, Maringá and Paranavaí. Ae. albopictus was generally less abundant and was not present in Ibiporã nor in the oviposition traps of a second collection of Maringá. The relation between sexes for Ae. aegypti was approximately 1:1. In the comparison of the number of adults collected between the two species, a negative correlation was obtained in the samples of Maringá and Cambé, what was attributed the seasonality of these populations. The coexistence of these species indicates that both are under pressure by the control programs, therefore specific evaluations are necessary.

Mosquito control prevails as the most efficient method to protect humans from the dengue virus, despite recent efforts to find a vaccine for this disease. We evaluated insecticide resistance and genetic variability in natural populations of Aedes aegypti (Linnaeus, 1762) from Colombia. This is the first Colombian study examining kdr mutations and population structure. Bioassays with larvae of three mosquito populations (Armenia, Calarcá and Montenegro) were performed according to the World Health Organization (WHO) guidelines, using Temephos. For the analysis of the Val1016Ile mutation and genetic diversity, we sampled recently-emerged adults from four mosquito populations (Armenia, Calarcá, Montenegro and Barcelona). Following the WHO protocol, bioassays implemented with larvae showed resistance to Temephos in mosquito populations from Armenia (77% ± 2) and Calarcá (62% ± 14), and an incipient altered susceptibility at Montenegro (88% ± 8). The RR95 of mosquito populations ranged from 3.7 (Montenegro) to 6.0 (Calarca). The Val1016Ile mutation analysis of 107 genotyped samples indicates that 94% of the specimens were homozygous for the wild allele (1016Val) and 6% were heterozygous (Val1016Ile). The 1016Ile allele was not found in Barcelona. Genetic variability analysis found three mitochondrial lineages with low genetic diversity and gene flow. In comparison with haplotypes from the American continent, those from this study suggest connections with Mexican and North American populations. These results confirm that a continuous monitoring and managing program of A. aegypti resistance in the state of Quindío is required.

Introducción. El alcaloide natural girgensohnina se ha usado como modelo en la síntesis de nuevos análogos de alcaloidales alfa-aminonitrílicos con efecto insecticida en vectores de enfermedades.Objetivo. Evaluar la actividad biocida de análogos de girgensohnina y de aceites esenciales de las plantas Cymbopogon flexuosus, Citrus sinensis y Eucalyptus citriodora en ninfas de estadios I y V de Rhodnius prolixus.Materiales y métodos. Se empleó la aplicación tópica en terguitos, esternitos y superficies tratadas con diferentes dosis exploratorias de cada una de las moléculas y aceites esenciales para determinar las dosis letales (LD50 y LD95).Resultados. El análogo 3 tuvo la mayor actividad insecticida, con una mortalidad de 83,3±16,7% en los terguitos, de 38,9±4,8 % en los esternitos y de 16,7±0 % a las 72 horas en ninfas de estadio I expuestas a superficies tratadas y 500 mg.L-1. En las ninfas de estadio V solo se presentó mortalidad en los esternitos (11,1±9,6 % con el análogo 6 y 5,5±4,7 % con los análogos 3 y 7 a las 72 h y 1.500 mg.L-1). Las dosis letales para la molécula 3 en los terguitos de ninfas de estadio I fueron las siguientes: DL50, 225,60 mg.L-1y DL95, 955,90 mg.L-1. En cuanto a los aceites esenciales, el efecto insecticida solo se presentó con C. flexuosus (11,1±4,8%) en los esternitos de ninfas de estadio I expuestas a superficies tratadas; con C. sinensis (5,6±4,8%) en los terguitos y en los esternitos (8,3±0%) a las 72 horas y 1.000 mg.L-1.Conclusión. Los análogos sintéticos del alcaloide girgensohnina y los aceites esenciales de C. flexuosus y C. sinensis exhibieron actividad insecticida en R. prolixus. El análogo 3 exhibió la mayor actividad insecticida de todas las moléculas evaluadas bajo las condiciones de laboratorio.

We provide eight new mosquito species records for Santa Catarina (Limatus flavisetosus Oliveira Castro 1935, Mansonia flaveola (Coquillett 1906), Ma. titillans (Walker 1848), Psorophora forceps Cerqueira 1939, Sabethes xyphydes Harbach 1994, Toxorhynchites bambusicolus (Lutz & Neiva 1913), Tx. theobaldi (Dyar & Knab 1906) and Wyeomyia lassalli Bonne-Wepster & Bonne 1921) and three for Paraná (Ochlerotatus argyrothorax Bonne-Wepster & Bonne 1920, Uranotaenia pallidoventer Theobald 1903 and Wyeomyia pilicauda Root 1928). Additionally, we list all species in these eight genera recorded previously in the two states. The known distribution and possible epidemiological implications of the new species records are discussed. Relatamos o primeiro encontro de oito espécies de mosquitos para Santa Catarina (Limatus flavisetosus Oliveira Castro 1935, Mansonia flaveola (Coquillett 1906), Ma. titillans (Walker 1848), Psorophora fórceps Cerqueira 1939, Sabethes xyphydes Harbach 1994, Toxorhynchites bambusicolus (Lutz & Neiva 1913), Tx. theobaldi (Dyar & Knab 1906) e Wyeomyia lassalli Bonne-Wepster & Bonne 1921) e três para o Paraná (Ochlerotatus argyrothorax Bonne-Wepster & Bonne 1920, Uranotaenia pallidoventer Theobald 1903 e Wyeomyia pilicauda Root 1928). Adicionalmente, apresentamos lista de todas as espécies destes oito gêneros com registro nos dois estados. A distribuição conhecida das espécies e sua possível importância epidemiológica são discutidas.

The dynamics of the control of Aedes (Stegomyia) aegypti Linnaeus, (Diptera, Culicidae) by Bacillus thuringiensis var israelensis has been related with the temperature, density and concentration of the insecticide. A mathematical model for biological control of Aedes aegypti with Bacillus thuringiensis var israelensis (Bti) was constructed by using data from the literature regarding the biology of the vector. The life cycle was described by differential equations. Lethal concentrations (LC50 and LC95) of Bti were determined in the laboratory under different experimental conditions. Temperature, colony, larvae density and bioinsecticide concentration presented marked differences in the analysis of the whole set of variables; although when analyzed individually, only the temperature and concentration showed changes. The simulations indicated an inverse relationship between temperature and mosquito population, nonetheless, faster growth of populations is reached at higher temperatures. As conclusion, the model suggests the use of integrated control strategies for immature and adult mosquitoes in order to achieve a reduction of Aedes aegypti. Foi elaborado um modelo matemático do controle biológico de Aedes aegypti com foco em Bacillus thuringiensis var israelensis (Bti). Na construção do modelo foram utilizados dados da literatura sobre a biologia do vetor, no qual o ciclo de vida foi descrito através de equações diferenciais. As concentrações letais (CL50 e CL95) do Bti foram determinadas no laboratório sob diferentes condições experimentais. As variáveis temperatura, colônia, densidade de larvas e concentração do bioinseticida acusaram diferenças significativas quando analisadas no modelo geral, porém quando analisadas individualmente, apenas a temperatura e concentração apresentaram diferenças. As simulações do modelo indicam que a temperatura afeta inversamente a produção de indivíduos e que os pontos máximos de produção de mosquitos são atingidos mais rápido a temperaturas maiores. Concluímos, com a simulação do modelo, que estratégias integradas de controle de imaturos e adultos devem ser utilizadas para atingir redução expressiva da população de Aedes aegypti.

Presentamos la construcción y la simulación de un modelo matemático, del tipo SIRS (SusceptibleInfeccioso Removido-Susceptible). Se utilizaron cuatro ecuaciones diferenciales para mostrar los parámetros más relevantes que deben ser seguidos en lucha contra vectores del dengue: θ (tasa de control cultural) y ϕ (tasa de protección de los criaderos con la aplicación de tratamiento biológico o químico por un tiempo determinado), dentro del control de criaderos que influencian directamente el número de mosquitos que está relacionado con los aspectos ambientales representados por la función Sen2. Intengrando el control cultural y el tratamiento convencional, se puede mantener el número de criaderos en niveles bajos y con ello, la población de mosquitos. Debe utilizarse un control integrado para disminuir el número de criaderos de mosquitos y así reducir la cantidad de los mismos

Se determino la susceptibilidad de larvas de Aedes albopictus en condiciones de laboratorio de origen del "Vale do Ribeira llha Cumprida" Sao Paulo, Brasil. El producto utilizado fue Bacillus thuringiensis var israelensis H-14 Vectobac-AS con 1.200 unidades internacionales de toxicidad (UIT) por miligramo. Como parametro de comparacion se empleo la colonia Aedes aegypti Rockefeller CDC (Center for Disease Control) de Puerto Rico. Las concentraciones letales obtenidas de Ae. albopictus fueron LC50= 0.12 ppm y LC90= 0,28 ppm y para la especie referenda Ae. aegypti fue CL50 de 0,07 ppm y CL95 de 0,17 ppm. Se puede concluir que Ae. albopictus presento una respuesta al bioinsecticida diferente a Ae. aegypti. The susceptibility of Aedes albopictus larvae, originating from "Vale do Ribeira llha Cumprida" Sao Paulo, Brasil. was determined under laboratory conditions. The product used was Bacillus thuringiensis var israelensis H-14 Vectobac-AS with 1,200 internacional toxic units (TU) per milligram. An Aedes aegypti Rockefeller colony from CDC (Center for Disease Control) of Puerto Rico was used as a reference. Lethal concentrations determined for Ae. albopictus were LC50= 0.12 ppm and LC95= 0.28 ppm and for the reference species Ae. aegypti they were LC(50)0.07 ppm and LC95 0.17 ppm. It is concluded that Ae. albopictus presented a different response to the bioinsecticide than Ae. aegypti.

Bioassays were performed in order to detect the susceptibility of Aedes aegypti to the chemical insecticides temephos and cypermethrin. The results showed that this species is susceptible to temephos and presents resistance to cypermethrin.

Ethanolic extracts from the kernels of ripe fruits from the Indian Lilac Melia azedarach and from the well-known Neem tree, Azadirachta indica were assayed against larvae of Aedes aegypti, the mosquito vector of dengue fever. The lethality bioassays were carried out according to the recommendations of the World Health Organization. Extracts were tested at doses ranging from 0.0033 to 0.05 g% in an aqueous medium for 24 and 48 h, at 25 or 30 degrees C, with or without feeding of the larvae. LC50, LC95 and LC99 were determined. Both seed extracts proved lethal for third to fourth instar larvae. Non-fed A. aegypti larvae were more susceptible to Azadirachta extracts at both temperatures. Under a more realistic environmental situation, namely with fed larvae at 25 degrees C, the death rates caused by the Melia extract were higher, although at 30 degrees C the extract of Azadirachta had an even higher lethality. Inter allia, the LC50 values for the crude extracts of these two members of the Meliaceae ranged from 0.017 to 0.034 g% while the LC99 values ranged from 0.133 to 0.189 g%. Since no downstream processing was undertaken to purify the active agents in the extracts, our findings seem very promising, suggesting that it may be possible to increase the larvicidal activity further by improving the extraction and the fractionation of the crude limonoids, for instance removing the co-extracted natural fats.

A model describing malaria behavior through a system of ordinary differential equations.In order to construct the model, the interaction between man and the malaria vector was taken into account in different infectivity and immunity states. We also considered the vaccination effect by means of an infection blocking vaccine and parameters representing larval and adult vector control.The model developed enables simulation of malaria disease behavior in various settings: in a natural manner without intervention, with either vector control or vaccination, and considering vector control and vaccination together.We obtained numerical conditions for the existence of a non-trivial equilibrium state, conditioned to the existence of a single real positive root of a fourth degree polynomial. This is a problem that remains unsolved.

Realizaram-se bioensaios para detectar a susceptibilidade de Aedes aegypti aos inseticidas químicos, temefós e cipermetrina. Os resultados mostraram que esta espécie é suscetível a temefós e apresenta resistência a cipermetrinae.Bioassays were performed in order to detect the susceptibility of Aedes aegypti to the chemical insecticides temephos and cypermethrin. The results showed that this species is susceptible to temephos and presents resistance to cypermethrin.