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.

A survey of the entomofauna associated with the inflorescences of pejibaye (Arecaceae: Bactris gasipaes Kunth) in the Ribeira Valley, SP, Brazil / Levantamento da entomofauna associada às inflorescências de pupunheira (Arecaceae: Bactris gasipaes Kunth) no Vale do Ribeira, SP

The cultivation of pejibaye (Bactris gasipaes Kunth) has been expanding in Brazil, especially in the Vale do Ribeira, SP, where the edaphoclimatic condition is compatible with its production. With the purpose of learning about insects that visit the inflorescence of pejibaye, a survey was conducted at Polo Regional do Vale do Ribeira, located in the municipality of Pariquera-açu, SP, Brazil, and on a private property located in the municipality of Registro, SP, areas where selected pejibaye palm trees from Yurimaguas, Peru, are grown. During the month of January of 2006 and 2007, yellow sticky insect traps were placed at the inflorescences of different pejibaye matrices, soon after the bracts opened. The traps were kept throughout female and male anthesis, and removed at the end of the cycle, which lasted for about 72 hours. The 9,743 insects collected were then separated, counted, and identified according to their orders. It was observed that the most frequent insects on the inflorescence of pejibaye palms in the Vale do Ribeira, SP are Diptera, Coleoptera, and Hymenoptera.

Levantamento da entomofauna associada às inflorescências de pupenheira (Arecaceae: bactris gasipaes kunth) no vale do Ribeira, SP. A cultura da pupunheira (Bactris gasipaes Kunth) vem se expandindo no Brasil, especialmente no Vale do Ribeira, SP, onde encontra condição edafoclimática compatível à sua produção. Com o objetivo de conhecer os insetos visitantes da inflorescência da pupunheira, foi realizado levantamento em duas áreas de coleção de pupunheiras selecionadas originárias de Yurimaguas, Peru, no - Polo Regional do Vale do Ribeira – APTA/SAA-SP, localizado no Município de Pariquera-açu, SP, e em uma propriedade particular no Município de Registro, SP. Durante o mês de janeiro de 2006 e 2007, foram instaladas armadilhas adesivas entomológicas amarelas em inflorescências de diferentes matrizes de pupunheira logo após a abertura de suas brácteas, as quais foram mantidas durante a antese feminina e masculina e retiradas no término do ciclo, cerca de 72 horas. Efetuou-se a separação, contagem e identificação ao nível de ordem dos 9.743 insetos totais coletados. Verificou-se que os insetos mais frequentes na inflorescência da pupunheira no Vale do Ribeira, SP, pertencem às ordens Diptera, Coleoptera e Hymenoptera.

Field optimisation of MosquiTRAP sampling for monitoring Aedes aegypti Linnaeus (Diptera: Culicidae)

A sticky trap designed to capture gravid Aedes (Stegomyia) aegypti mosquitoes, MosquiTRAP, has been evaluated for monitoring this species in Brazil. However, the effects of trap densities on the capture rate of Ae. aegypti females and the sensitivity of vector detection are still unknown. After a preliminary study has identified areas of high and low female mosquito abundance, a set of experiments was conducted in four neighbourhoods of Belo Horizonte (state of Minas Gerais, Brazil) using densities of 1, 2, 4, 8, 16, 32 and 64 traps per block. Trap sensitivity (positive MosquiTRAP index) increased significantly when 1-8 MosquiTRAPs were installed per block in both high and low abundance areas. A strong fit was obtained for the total number of mosquitoes captured with increasing trap densities through a non-linear function (Box-Lucas) (r² = 0,994), which likely exhibits saturation towards an equilibrium level. The capacity of the Mean Female Aedes Index to distinguish between areas of high and low Ae. aegypti abundance was also investigated; the achieved differentiation was shown to be dependent on the MosquiTRAP density.

Avaliação da operacionalidade da armadilha MosquiTRAP no monitoramento de Aedes aegypti / Operational evaluation of a sticky trap in the monitoring of Aedes aegypti

Objetivo: avaliar a capacidade dos agentes de saúde para identificar corretamente os mosquitos capturados pela MosquiTRAP e comparar o tempo gasto na pesquisa larvária, ovitrampa e MosquiTRAP. Metodologia: aspectos operacionais do monitoramento de Aedes aegypti foram avaliados em doze municípios das cinco regiões geográficas do Brasil. Resultados: o tempo gasto pelos agentes de saúde na vistoria da MosquiTRAP foi semelhante ao da ovitrampa (8,0 e 6,8 min., respectivamente) e ambos foram inferiores a pesquisa larvária (24,8 min.). Os agentes de saúde identificaram A. aegypti (mínimo de 97,4 por cento de acerto) e Aedes albopictus (100 por cento de acerto) em cinco dos seis municípios onde esta espécie foi registrada. O índice de pendência da MosquiTRAP em todos os municípios variou entre 0,20 por cento e 4,43 por cento. Conclusão: os resultados indicam que a ovitrampa e MosquiTRAP apresentaram vantagens em relação a pesquisa larvária com redução do tempo de vistoria das casas, implicando uma redução de custos.

Objectives: to assess the capacity of health workers to correctly identify mosquitoes captured by MosquiTRAP, and to compare the time spent on larval survey, egg trap (ovitrap) and MosquiTRAP. Methodology: operational aspects of monitoring of the Aedes aegypti were assessed in twelve municipalities in five geographic regions of Brazil. Results: time spent by health workers to inspect the MosquiTRAP was similar to ovitrap (8.0 and 6.8 minutes, respectively) and both took less than larval survey (24.8 minutes). Health workers identified A. aegypti (minimum of 97.4 percent hit) and A. albopictus (100 percent hit) in five of the six municipalities where this species was recorded. MosquiTRAP pendency index in all municipalities varied from 0.20 percent to 4.43 percent. Conclusion: results indicate that ovitrap and MosquiTRAP have advantages over larval survey in terms of reduced time spent at residences, implying cost reduction.

Population dynamics and damage caused by the leafminer Liriomyza huidobrensis blanchard (Diptera: Agromyzidae), on seven potato processing varieties grown in temperate environment

The leafminer Liriomyza huidobrensis Blanchard is considered a key pest for potatoes in Argentina. Population dynamics and leaf damage caused by the leafminer on seven selected potato processing varieties were assessed at Balcarce during the 2002 and 2003 growing seasons. Adult population dynamic was monitored using yellow sticky traps, while leaf damage (punctures and mines) was assessed using a damage index scale from low to severe. Liriomyza huidobrensis adults were present throughout the growing season and the population increased along crop development. The same was true for all varieties regarding larval damage, being low on early crop stages and severe late in the season. Varieties were grouped in two different categories according to damage scale index. Shepody, Kennebec, Frital and Innovator showed a higher damage index when compared with Santana, Ranger Russet and Russet Burbank, which exhibited a lower damage. Moreover, it could be assumed that damage was related to the foliage greenness, with light green colored varieties (Shepody, Kennebec, Frital and Innovator) being more attractive and affected by L. huidobrensis.

Evaluación del color y la posición de trampas en la captura de cicadélidos en Gaultheria phillyreifolia (Ericaceae) afectadas por fitoplasmas / Evaluation of trap color and position on the capture of cicadellids in Gaultheria phillyreifolia (Ericaceae) affected by phytoplasmas

Color sticky traps are one of the main alternatives to collect insect vectors, as they are easy to handle and are inexpensive. We aimed to compare the effect of color and height of the traps on the attractiveness to potential cicadellids vectors of plant pathogens. Yellow and green colored stick traps were placed at two different heights in plant of Gaultheria phillyreifolia. Seventeen leafhopper species were identified, with Ribautiana tenerrima Herrich-Shãffer (49 percent), Carelmapu ramosi Linnavuori & DeLong (33 percent), Carelmapu aurionitens Linnavuori (5 percent) and Atanus sp. (6 percent) being the most common. All these species were significantly attracted by yellow sticky traps. Ribautiana tenerrima was the only species affected by the height of the sticky traps. However, this was also dependent on the sampling season. The phytoplasma vector candidate, C. ramosi, showed two population peaks in early and late summer, which may indicate two different generations. Males of this species were more abundant than females on sticky traps, but were both similarly attracted to yellow sticky traps. No differences were detected in the capture efficiency of both sexes at any height of the traps. The high proportion of C. ramosi captured suggests that the yellow sticky traps can be an important element for monitoring this species.

Las trampas pegajosas de colores son una de las principales alternativas en la captura de insectos vectores, debido a su bajo costo y su fácil implementación. El objetivo fue comparar las preferencias a los colores y la altura de colocación de trampas para los posibles cicadélidos vectores de fitopatógenos. Trampas pegajosas amarillas y verdes fueron colocadas en plantas de Gaultheria phillyreifolia a dos distintas alturas. Se diferenciaron 17 especies de cicadélidos, siendo Ribautiana tenerrima Herrich-Shãffer (49 por ciento), Carelmapu ramosi Linnavuori & DeLong, Carelmapu aureonitens Linnavuori (33 y 5 por ciento), Atanus sp. (6 por ciento) las especies más comunes. Todas estas especies se vieron significativamente atraídas por trampas de color amarillo. Ribautiana tenerrima fue la única especie afectada por la altura de las trampas pegajosas, aunque este efecto fue influenciado por la temporada de colecta. La especie candidato a vector, C. ramosi, presentó dos curvas de crecimiento al inicio y finales del verano, lo cual puede representar la emergencia de dos generaciones distintas. Machos de esta especie fueron más abundantes que las hembras en las trampas pegajosas, pero ambos con una similar preferencia hacia el color amarillo. Además, no se detectaron diferencias en la posición de las trampas en la captura de ambos sexos. La alta proporción capturada de C. ramosi, sugiere que trampas de color amarillo pueden ser um elemento importante en el monitoreo de esta especie.