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.

Capture of Triatoma arthurneivai (Hemiptera: Reduviidae) using a new luminous trap in Southeast Brazil / Captura de Triatoma arthurneivai (Hemiptera: Reduviidae) por nova armadilha luminosa no sudeste do Brasil

INTRODUÇÃO: As capturas de triatomíneos em meio silvestre são laboriosas e demoradas. Algumas armadilhas podem auxiliar nessa tarefa. Relata-se novo modelo de armadilha e captura de exemplar de espécie de triatomíneo raramente encontrada. MÉTODOS: Duas armadilhas luminosas foram instaladas em Diamantina, Estado de Minas Gerais e acompanhadas, semanalmente, durante um ano. RESULTADOS: Uma fêmea de Triatoma arthurneivai foi capturada além de outros triatomíneos. CONCLUSÕES: Um novo modelo de armadilha poderá ser empregado na captura de triatomíneos principalmente em áreas de baixa densidade. Presume-se que o centro de endemismo de Triatoma arthurneivai seja a Cordilheira do Espinhaço.

INTRODUCTION: Triatomine bug captures in the wild are laborious and time-consuming. Some traps may assist in this task. We report a new trap design and the capture of a specimen of a triatomine rarely found. METHODS: Two luminous traps were installed in the city of Diamantina, State of Minas Gerais, and surveyed weekly for a year. RESULTS: A Triatoma arthurneivai female and other triatomine bugs were caught. CONCLUSIONS: A new trap design may be used in triatomine bugs field captures, mainly in low density areas. We assume the center of endemism of Triatoma arthurneivai is the Espinhaço Mountain range.

SECTAB: a new device for tabanid storage in field collections / SECTAB: um novo instrumento para armazenamento de tabanídeos em coletas de campo

O artigo descreve a construção de um novo aparato simples, para o armazenamento e transporte de tabanídeos vivos durante as coletas realizadas em campo, evitando a perda de espécimes.

The article describes the construction of a simple new device, for the storage of live tabanids during field collections and their transportation to the laboratory, avoiding the loss of specimens.

Validação da armadilha adultrap® para capturade dípteros muscoides / Validation of the adultrap® trap for capture of muscoids dipterans

O potencial da armadilha adultrap® para captura de dípteros muscoides foi avaliado por comparação com a armadilha descrita por Ferreira (1978) e adaptada por Fraga e d' Almeida (2005). Iscas de sardinha foram utilizadas em ambas as armadilhas. O teste de Wilcoxon para duas amostras não pareadas foi empregado para comparação das armadilhas. Capturou-se um total de 8.909 dípteros muscoides, sendo 57,51 por cento desses pela adultrap®, mas sem diferença significativa (p = 0,147) entre as armadilhas. Do total de sarcofagídeos, califorídeos, muscídeos e de outras famílias de dípteros muscoides 79, 68, 29 e 31 por cento, respectivamente, foram capturados pela adultrap® com diferença estatística (p = 0,002) entre as armadilhas apenas para a família Sarcophagidae. Os resultados da adultrap® foram similares ao modelo modificado por Fraga e d' Almeida (2005). Entretanto, adultrap® foi mais eficiente na captura de dípteros da família Sarcophagidae.

The potential of adultrap® for capture of muscoid dipterans was evaluated by comparison with the trap described by Ferreira (1978) and adapted by Fraga and d' Almeida (2005). Sardine baits were used in both traps. The Wilcoxon two-sample test was used for trap comparison. A total of 8,909 muscoid dipterans was caught, 57.51 percent of them by the adultrap®. However, there was no significant difference (p = 0.147) between trap efficiency. From the total of sarcophagids, calliphorids, muscids and other families of muscoid flies, 79, 68, 29 and 31 percent were caught by adultrap®, respectively. Statistical difference (p = 0.002) between traps was found only for Sarcophagidae. The results of adultrap® were similar to the model used by Fraga and d'Almeida (2005), thus validating its use for seasonal fluctuation studies of muscoid dipterans. However, adultrap® has the highest efficiency in capturing Sarcophagidae flies.

Calibration and evaluation of field cage for oviposition study with Aedes (Stegomyia) aegypti female (L.) (Diptera: Culicidae) / Calibração e avaliação de semi-campo para estudos de oviposição para fêmeas de Aedes (Stegomyia) aegypti (L.) (Diptera: Culicidae)

Differences among results gathered from insect behavior studies conducted in laboratory and field situations are due to ambient variables that differ greatly between both environments. In laboratory studies the environmental conditions can be controlled whereas in field temperature, humidity and air velocity vary uncontrollably. The objective of this study was to calibrate and evaluate an experimental area (field cage) (14 x 7 x 3.5 m) subdivided into eight test cages (2.5 x 2.5 x 2 m) for use in behavioral oviposition tests of Aedes aegypti (L.) mosquitoes for developing a new methodology to assess attractants and oviposition traps. Test cage calibration involved: (1) minimal experiment duration tests; (2) optimal female release number per traps test and (3) trap placement tests. All tests used gravid A. aegypti females; 3-4 days post blood meal and the sticky trap MosquiTRAP® to catch adults. Ninety percent of the females released were recaptured 2h after the beginning of the experiment, and this allowed up to 32 test repetitions/day to be conducted in the field cage. The minimum number of females necessary to conduct statistical analyses was 20 females/trap/test per cage. No significant difference was found in the behavioral response of gravid females to four different trap positions within test cages. Field trapping results with attractant were similar to those in the field cage. Therefore, the field cage could replace field trapping for evaluating at least mosquito traps and oviposition attractants for A. aegypti.

Discrepâncias entre resultados de estudos de comportamento de insetos em laboratório e em campo ocorrem devido a variáveis encontradas entre os ambientes. Enquanto em laboratório as condições são controladas, em campo os insetos são avaliados em condições variáveis de temperatura, umidade e velocidade do ar. O objetivo deste trabalho foi calibrar e avaliar uma área experimental (14 x 7 x 3,5 m) contendo oito gaiolas de teste (2,5 x 2,5 x 2 m), para estudos comportamentais de oviposição para Aedes aegypti (L.) visando desenvolver uma nova metodologia para avaliar atraentes e armadilhas de oviposição em semi-campo. A calibração consistiu na (1) determinação do tempo de realização dos experimentos e no (2) número de fêmeas liberadas por teste e na (3) avaliação das posições das armadilhas no interior das gaiolas de teste. Fêmeas de A. aegypti de 3-4 dias após repasto sangüíneo e MosquiTRAP® foram utilizadas nos experimentos. Noventa por cento das fêmeas liberadas foram recapturadas após 2h do início dos experimentos, permitindo a realização de até 32 repetições/dia. A amostra mínima de fêmeas por experimento para a realização de análises estatísticas foi limitada a 20 fêmeas/armadilha/gaiola. Não foi observada diferença na resposta comportamental das fêmeas nas diferentes posições avaliadas. Resultados com MosquiTRAP em área urbana foram semelhantes aos do semi-campo. Portanto, a metodologia pode substituir os testes de campo para avaliar pelo menos armadilhas e atrativos de oviposição para A. aegypti.

Field evaluation of effectiveness of the BG-Sentinel, a new trap for capturing adult Aedes aegypti (Diptera: Culicidae)

In recent years, the development of new tools to gather field information about vector ecological parameters has increased. This report evaluated the BG-Sentinel Trap (BGS-Trap), a promising new attempt to improve collection of the dengue vector, Aedes aegypti. The efficacy of the BGS-Trap was compared with the CDC backpack aspirator, one of the commonest used methods for capturing adult mosquitoes. BGS-Traps captured significantly more Ae. aegypti males (chi2 = 21.774, df = 1, P < 0.05) and females (chi2 = 56.007, df = 1, P < 0.05) than CDC aspirator during all days of field collection. However, CDC aspirator was significantly more efficient to capture Culex quinquefasciatus males (chi2 = 5.681, df = 1, P < 0.05) and females (chi2 = 6.553, df = 1, P < 0.05). BGS-Traps captured host-seeking females (varying between 68.75 to 89.8 percent) in detriment of females in other behavioral and physiological stages. BGS-Traps proved to be efficient and can be used for monitoring adult mosquito populations.

HP: um modelo aprimorado de armadilha luminosa de sucção para a captura de pequenos insetos / HP: an improved model of sucction light trap for the capture of small insects

Descreve-se um novo tipo de armadilha, resultado do aprimoramento de um modelo muito utilizado, conhecido como CDC. A nova armadilha, denominada HP, apresenta como vantagens alta eficiência, facilidade no manuseio e transporte, além de ser confeccionada quase que exclusivamente com material nacional, o que reduz consideravelmente seu custo final.

Effect of selected chemicals on mosquito larval orientation behaviour using a new apparatus.

An apparatus was designed and fabricated for studying the effects of aromatic chemicals on the IV instar larvae of Aedes aegypti (L.). The test chemicals (essential oils and monoterpenoids) were incorporated in agar along with yeast and dog biscuits which formed an attractant food source (bait). A fairly rapid decrease in the migration of larvae towards the bait cum chemical source was observed during the first hour after which a steady state was observed. Minimum migration (9.67%) was seen with terpeneol anhydrous and maximum (15.0%) with beta-citronellal as compared to control (65.67%), at the end of a 4 hr exposure period. Food particles were also detected on microscopic examination.