Ivoneide M. Silva

Evaluation of the sticky MosquiTRAP™ for detecting Aedes (Stegomyia) aegypti (L.) (Diptera: Culicidae) during the dry season in Belo Horizonte, Minas Gerais, Brazil

MosquiTRAP is a sticky trap specifically designed to capture gravid females of Aedes aegypti (L.) and allows the identification of the mosquito in the field during the inspection of the trap. This study aims to compare this sticky trap to larval and ovitrap surveys for field monitoring of A. aegypti during the dry season. The study was conducted from March to June of 2003 in 20 blocks of the district of Itapoã, Belo Horizonte, MG. The traps were monitored every week while the larval survey was conducted on a monthly basis. The larval index: Premise Index (PI) and Breteau Index (BI) had equal values throughout the experiment (1.72 in the first two months and zero in the last two). The container index (CI) during the first two months was 0.09 and 0.1%, respectively and zero in the last two. The Ovitrap Positive Index (OPI) ranged from 16.7 to 76.9%, and the MosquiTRAP Positive Index (MPI) ranged from 0 to 31.5%. The Egg Density Index (EDI) ranged from 26.6 to 82.8, while the Adult Density Index ranged from 0 to 1.6 throughout the experiment. Temperature and rainfall did not affect the Positive and Density Indices, although these environmental variables seemed to have affected the larvae indices. Although the MosquiTRAP caught a low number of Aedes mosquitoes during the study, it was more sensitive than the larval survey to detect the presence of Aedes mosquitoes.

LABORATORY EVALUATION OF MOSQUITO TRAPS BAITED WITH A SYNTHETIC HUMAN ODOR BLEND TO CAPTURE AEDES AEGYPTI

ABSTRACT A synthetic blend of chemicals comprising volatiles released by the human body has been shown to be an effective attractant for female Aedes aegypti in olfactometer bioassays with laboratory-reared mosquitoes. We report the laboratory evaluation of Ae. aegypti response to a synthetic blend tested with 4 types of mosquito traps (CDC model 512, CDC model 1012, CFG, and Fay–Prince traps). Aedes aegypti females were attracted significantly by the blend. The higher release rate of attractant (320.2 ± 10.71 mg/h) more efficiently attracted mosquitoes than the lower release rate (42.0 ± 2.3 mg/h). Although both the Fay–Prince and CFG traps caught higher number of mosquitoes than the other traps, only the CFG trap caught a statistically significant greater number of mosquitoes. The results suggest that the synthetic blend is effective in attracting Ae. aegypti females under controlled laboratory conditions (i.e., a closed system). Further studies are needed to evaluate the efficacy of this blend in baited traps under field conditions.

Development of the BG-Malaria trap as an alternative to human-landing catches for the capture of Anopheles darlingi.

Although the human-landing catch (HLC) method is the most effective for collecting anthropophilic anophelines, it has been increasingly abandoned, primarily for ethical considerations. The objective of the present study was to develop a new trap for the collection of Anopheles darlingi . The initial trials were conducted using the BG-Sentinel trap as a standard for further trap development based on colour, airflow direction and illumination. The performance of the trap was then compared with those of the CDC, Fay-Prince, counterflow geometry trap (CFG) and HLC. All trials were conducted outdoors between 06:00 pm-08:00 pm. Female specimens of An. darlingi were dissected to determine their parity. A total of 8,334 anophelines were captured, of which 4,945 were identified as An. darlingi . The best trap configuration was an all-white version, with an upward airflow and no required light source. This configuration was subsequently named BG-Malaria (BGM). The BGM captured significantly more anophelines than any of the other traps tested and was similar to HLC with respect to the number and parity of anophelines. The BGM trap can be used as an alternative to HLC for collecting anophelines.

A comparison of larval, ovitrap and MosquiTRAP surveillance for Aedes (Stegomyia) aegypti

In Brazil, the entomological surveillance of Aedes (Stegomyia) aegypti is performed by government-mandated larval surveys. In this study, the sensitivities of an adult sticky trap and traditional surveillance methodologies were compared. The study was performed over a 12-week period in a residential neighbourhood of the municipality of Pedro Leopoldo, state of Minas Gerais, Brazil. An ovitrap and a MosquiTRAP were placed at opposite ends of each neighbourhood block (60 traps in total) and inspections were performed weekly. The study revealed significant correlations of moderate strength between the larval survey, ovitrap and MosquiTRAP measurements. A positive relationship was observed between temperature, adult capture measurements and egg collections, whereas precipitation and frequency of rainy days exhibited a negative relationship.

Development of a New Mosquito Retention System for the BG-Malaria Trap To Reduce The Damage To Mosquitoes.

Abstract The BG-Malaria trap was recently modified from the BioGents BG-Sentinel trap to collect Anopheles species, including Anopheles darlingi. However, the captured mosquitoes often lose their hind legs in the collector bag, making them difficult to identify. To develop a new collector system that is capable of maintaining the integrity of the mosquitoes collected in the BG-Malaria trap, we conducted a study in the municipalities of Belém (Pará State [PA]) and Porto Velho (Rondônia State [RO]), Brazil, using carbon dioxide–baited BG-Malaria traps with 4 different mosquito collector systems: standard, no bag, rigid short, and rigid long. Results indicated significant differences among the numbers of mosquitoes captured in the 4 different collectors (P < 0.05). Additionally, significantly fewer insects (P < 0.05) were damaged using the rigid short and rigid long collectors than by using the standard and no-bag collectors. We observed that the longer the insects remained in the collector, the higher the number of damaged insects; this effect was the greatest in the standard collector. The results of this study indicate that rigid long collectors were the best suited for use in the BG-Malaria trap.

Avaliação da operacionalidade da armadilha MosquiTRAP no monitoramento de Aedes aegypti

Endereço para correspondência: Avenida Antônio Carlos 6627, Belo Horizonte-MG, Brasil. CEP: 31270-901 E-mail: resendemarcelo@ig.com.br, marcelo.resende@funasa.gov.br Marcelo Carvalho de Resende Laboratório de Ecologia Química de Insetos Vetores, Departamento de Parasitologia, Universidade Federal de Minas Gerais, Belo Horizonte-MG, Brasil Coordenação Regional, Fundação Nacional de Saúde, Ministério da Saúde, Belo Horizonte-MG, Brasil

Periodicidade de captura de Anopheles darlingi Root (Diptera: Culicidae) em Porto Velho, RO

Anopheles darlingi Root is the principal malaria vector in Amazonia region. The objectives of this work were to study the periodicity of Anopheles darlingi Root, the host preference for peri or extra-domestic environments and the parous rate in four field sites in Porto Velho (RO) by human-landing. All of the Anopheles specimens collected were identified, but only A. darlingi was dissected for the parous study. The results showed that human-landing colleted a total of 985 anophelines, with A. darlingi (972) being the most abundant species. Female mosquitoes were more abundant at extra-domestic environments in two of the locations studied (Sao Joao e Candeias do Jamari) (P < 0.05). The parous rate was 96% and no periodicity was observed for captures of females of A. darlingi in the field sites.

Evaluating the Adaptation Process of Sandfly Fauna to Anthropized Environments in a Leishmaniasis Transmission Area in the Brazilian Amazon

Abstract Phlebotomines (Diptera: Psychodidae) are vectors of several etiological agents of human and animal diseases, including protozoans of the gender Leishmania. Precarious socioeconomic conditions and uncontrolled population growth directly influence the transmission risk of parasites and the urbanization of vector species, previously restricted to wild environments. The Marajó Archipelago is considered a high incidence area of leishmaniasis in the Brazilian Amazon. However, it is poorly studied. The aim of this study was to assess the adaptation processes of phlebotomine species to anthropized environments in this region. For this purpose, the phlebotomine fauna was compared between three municipalities of the Marajó Archipelago: Anajás, Portel, and São Sebastião da Boa Vista. To survey the phlebotomine fauna, CDC (Center for Disease Control) light traps were installed in the wild areas and in the intra and peridomiciliary areas of rural and urban environments. The environments studied presented a diversified phlebotomine fauna, with higher richness in the wild environment (15 species), followed by the rural (seven species), and finally, the urban environment (three species). A migration of wild fauna to the adjacent anthropized areas (rural environment) and to urban areas was observed, evidencing the adaptation process of this vector to anthropized environments in the studied region. Thus, our study evidenced that the disorganized human occupation and utilization of the landscape might cause the invasion of urban areas by wild populations of phlebotomines, in this way enabling the settlement of urban leishmaniasis transmission cycles.

Fauna of Culicidae in rural areas of Porto Velho and the first record of Mansonia (Mansonia) flaveola (Coquillet, 1906), for the state of Rondônia, Brazil

INTRODUCTION Knowledge concerning the fauna of Culicidae in the Brazilian Amazon States contributes to current understanding of the bionomics of the insects collected and makes it possible to observe changes in the fauna over time. METHODS The Culicidae were captured with a BG-Sentinel® trap in extra-domiciliary area of two rural regions of Porto Velho in June and July of 2007 and 2008. RESULTS A total of 10,695 Culicidae was collected, belonging to nine genera: Coquillettidia, Culex, Mansonia, Psorophora, Aedes, Aedeomyia, Anopheles, Uranotaenia and Wyeomyia. CONCLUSIONS The presence of Mansonia (Mansonia) flaveola was recorded in the State of Rondônia for the first time.