RESUMO

Light-Emitting Diodes (LEDs) have been effective light sources in attracting Anopheles mosquitoes, but the broad-spectrum white light, even with a wide-ranging application in lighting, have not been evaluated yet. In this study, the white light was field evaluated against the green one in the light trapping of anopheline mosquitoes by using two non-suction Silva traps and two CDC-type suction light traps. Anopheline mosquitoes were captured for two 21-night periods of collecting (2022 and 2023). In the first period, two LEDs were used per Silva trap, but three were used in the second one to increase the luminance/illuminance at traps. A CDC-type suction light trap equipped with an incandescent lamp was used in 2022 and a CDC-type suction light trap equipped with a 6 V-white light (higher luminance/illuminance) in 2023. A total of eight species and 3,289 specimens were captured in both periods. The most frequent species were Anopheles triannulatus s.l., An. goeldii, An. evansae and An. argyritarsis. In 2022, white LEDs were less attractive to anopheline mosquitoes than the other light sources, but without statistical difference among treatments (F = 2.703; P = 0.0752; df = 2). In 2023, even with an increased luminance/illuminance at traps, no statistical difference was found between the two LED-baited Silva traps (F = 6.690; P = 0.0024; df = 2), but rather between the 6 V-white-baited CDC-type suction light trap and green-baited Silva traps. Due to some drawbacks and the lower abundance of individuals caught by using white LEDs, the narrow-banded green LEDs is preferable to white ones for attracting anophelines.

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Studies on the timing of anopheline host-seeking are important for understanding mosquito ecology, behaviors, and possible role in disease transmission. To study the evening crepuscular host-seeking activity of anophelines and the effects of moonlight, anopheline mosquitoes were collected with light traps settled in a livestock area in the Brazilian Cerrado region. Traps (Silva traps) were placed next to animal enclosures at 1.5 m asl. The research was divided in 2 experiments: the first experiment (12 nights) comprised 2 trapping periods, one from 6 PM to 7 PM and one from 7 PM to 6 AM, and the second experiment (16 evenings) divided in three 20-min intervals based on the 3 twilight phases (civil: 6-6:20 PM; nautical: 6:20-6:40 PM; and astronomical: 6:40-7 PM). A total of 2,815 anopheline mosquitoes and 9 species were found. The main species were Anopheles triannulatus s.l., An. argyritarsis, An. goeldii, and An. evanse. Host-seeking mosquitoes were more frequently active during the first hour after sunset, with a significant peak in the second 20-min interval. After that, a decrease in the number of individuals was observed from the astronomical twilight onwards. Moonlight did not affect the evening flight activity of anophelines. By using LED-based passive light traps, the evening arrival time of anophelines at blood-feeding sites was demonstrated, and it may be a key time window for malaria vector control interventions.

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Light traps have been widely used for monitoring malaria vectors, although drawbacks remain. In this context, new tools and attractants are always becoming available to perform monitoring tasks, like the Silva trap, a passive and low-cost LED-light trap for host-seeking anopheline mosquitoes. In this work, the effectiveness of the Silva trap by using UV-LED and at different heights as well as a comparison with the conventional CDC-type (HP) light trap was studied. A total of 9009 mosquitoes and nine species were caught, Anopheles triannulatus, An. argyritarsis, and An. goeldii being the most frequent species. The green (520 nm) and blue (470 nm) LEDs attracted almost equal numbers of anopheline mosquitoes, but UV LEDs (395 nm) attracted a significantly lower number of individuals (Kruskal-Wallis = 19.68, P = 0.0001). Even with the predominance of mosquitoes trapped at the height of 1.5 m, no significant statistical difference was found among the four heights tested (0.5 m; 1.0 m; 1.5 m; 2.0 m). Green-baited Silva traps collected significantly more individuals than incandescent-baited CDC-type traps (U = 60.5; P = 0.0303). LEDs have been useful as light sources for attracting insect vectors and together with a low-cost trap, as the Silva trap, a feasible alternative to conventional trap-based monitoring Anopheles mosquitoes that can be implemented in the field.

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One strategy to identify transmission foci is based on vector monitoring, and efficient methods are important for vector control. Our study evaluated different light sources (red, green, ultraviolet, blue, and incandescent light) to capture sand fly in Porto Velho, Brazil. We also evaluated Leishmania and blood meal sources in females. A total of 1,943 individuals were identified in 45 species level-taxa, with Trichophoromyia ubiquitalis (Mangabeira) (n = 364), Nyssomyia antunesi (n = 241), Bichromomyia flaviscutellata (Mangabeira) (n = 222), and Psychodopygus davisi (Root) (n = 148) being the most abundant. Incandescent light captured most individuals (n = 589), followed by blue (n = 471), green (n = 452), ultraviolet (n = 281) and red (n = 150). No significant difference was observed between the species composition and lights (PERMANOVA: Pseudo F = 1.29, p = 0.14, NMDS: Stress 0.18). The Shannon and Simpson indices demonstrated a high diversity captured using all lights. Our data demonstrated that LEDs are alternative devices for sand fly capture, with blue and green LEDs presenting similar results to incandescent light. 53 pools were analyzed, only one pool was positive for kDNA and hsp70 targets [Nyssomyia fraihai (Martins, Falão & Silva)] and identified as Endotrypanum spp., suggesting that other trypanosomatids may circulate in the locality. Choloepus hoffmanni (two-toed sloth) Peters, Homo sapiens Linnaeus, Proechimys gardneri (Gardner's spiny rat) Da Silva, and Tamandua tetradactyla (lesser anteater) (Linnaeus) were blood meal sources identified in females, increasing the knowledge about sources used by these insects.

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The species of the Culicoides genus are hematophagous, and some of them are vectors of important human and animal diseases. This group of insects is distributed worldwide, varying according to local species. Knowledge of the geographic distribution of specific species is crucial for the development and implementation of control strategies. The aim of this work was to investigate the occurrence of Culicoides in the state of Alagoas in northeast Brazil. Midges were captured with CDC light traps, and their identification and morphological analyses were performed by the Ceratopogonidae Collection of the Oswaldo Cruz Foundation (FIOCRUZ/CCER) in Rio de Janeiro, Brazil. Morphological analyses were performed using the key to Culicoides from the guttatus group and comparison with other deposited specimens. DNA sequencing, genetic analysis and comparison with sequences in the Genbank database, confirmed the identification of the flies as Culicoides insignis. This was the first formal report of C. insignis being found in Alagoas.

RESUMO

Automated species identification based on data produced with metabarcoding offers an alternative for assessing biodiversity of bulk insect samples obtained with traps. We used a standard two-step PCR approach to amplify a 313 bp fragment of the barcoding region of the mitochondrial COI gene. The PCR products were sequenced on an Illumina MiSeq platform, and the OTUs production and taxonomic identifications were performed with a customized pipeline and database. The DNA used in the PCR procedures was extracted directly from the preservative ethanol of bulk insect samples obtained with automatic light traps in 12 sampling areas located in different biomes of Brazil, during wet and dry seasons. Agricultural field and forest edge habitats were collected for all sampling areas. A total of 119 insect OTUs and nine additional OTUs assigned to other arthropod taxa were obtained at a ≥97% sequence similarity level. The alpha and beta diversity analyses comparing biomes, habitats, and seasons were mostly inconclusive, except for a significant difference in beta diversity between biomes. In this study, we were able to metabarcode and HTS adult insects from their preservative medium. Notwithstanding, our results underrepresent the true magnitude of insect diversity expected from samples obtained with automatic light traps in Brazil. Although biological and technical factors might have impacted our results, measures to optimize and standardize eDNA HTS should be in place to improve taxonomic coverage of samples of unknown diversity and stored in suboptimal conditions, which is the case of most eDNA samples.

RESUMO

This study aimed to investigate the effectiveness of ultraviolet (UV) insect light traps for mosquito control and to study the relationship between this effect and weather factors in coastal areas of Samut Songkhram province, Thailand. The study sites were divided into two areas, approximately 2 and 4km from the sea. The trap was placed less than one meter away from the house, where it could reach electrical plugs. The effectiveness of UV light trap was tested from September to October 2017 between 6: 00 p.m. and 6: 00a.m., for a total of 30days. A total of 2,605 adult mosquitoes within four species belonging to two genera were collected, including Anopheles epiroticus Linton & Harbach, Culex quinquefasciatus Say, Cx. sitiens Wiedmann and Cx. gelidus Theobald. The effectiveness of UV insect light traps in area 2 km from the sea trapped 45.96 ± 42.13 mosquitoes per night and area 4 km from the sea trapped 40.83 ± 33.61 mosquitoes per night. While, effectiveness comparison of the UV insect light traps 2 and 4 km from the sea of were shown to be statistically significantly different (p < 0.05). These results of this study are useful for planning and application of UV light traps to control mosquito populations in coastal areas of Samut Songkhram province, Thailand and other coastal areas.

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This study aimed to investigate the effectiveness of ultraviolet (UV) insect light traps for mosquito control and to study the relationship between this effect and weather factors in coastal areas of Samut Songkhram province, Thailand. The study sites were divided into two areas, approximately 2 and 4km from the sea. The trap was placed less than one meter away from the house, where it could reach electrical plugs. The effectiveness of UV light trap was tested from September to October 2017 between 6: 00 p.m. and 6: 00a.m., for a total of 30days. A total of 2,605 adult mosquitoes within four species belonging to two genera were collected, including Anopheles epiroticus Linton & Harbach, Culex quinquefasciatus Say, Cx. sitiens Wiedmann and Cx. gelidus Theobald. The effectiveness of UV insect light traps in area 2 km from the sea trapped 45.96 ± 42.13 mosquitoes per night and area 4 km from the sea trapped 40.83 ± 33.61 mosquitoes per night. While, effectiveness comparison of the UV insect light traps 2 and 4 km from the sea of were shown to be statistically significantly different (p < 0.05). These results of this study are useful for planning and application of UV light traps to control mosquito populations in coastal areas of Samut Songkhram province, Thailand and other coastal areas.(AU)

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Phlebotominae are the vectors of Leishmania parasites. It is important to have available surveillance and collection methods for the sand fly vectors. The objectives of the present study were to evaluate and compare traps for the collection of sand fly species and to analyze trap catches along months and transects. Field evaluations over a year were conducted in an endemic area of leishmaniasis in the state of Quintana Roo, Mexico. A randomized-block design was implemented in study area with tropical rainforest vegetation. The study design utilized 4 transects with 11 trap types: 1) Centers for Disease Control and Prevention (CDC) light trap with incandescent bulb (CDC-I), 2) CDC light trap with blue light-emitting diodes (LEDs) (CDC-B), 3) CDC light trap with white LEDs (CDC-W), 4) CDC light trap with red LEDs (CDC-R), 5) CDC light trap with green LEDs (CDC-G), 6) Disney trap, 7) Disney trap with white LEDs, 8) sticky panels, 9) sticky panels with white LEDs, 10) delta-like trap, and 11) delta-like trap with white LEDs. A total of 1,014 specimens of 13 species and 2 genera (Lutzomyia and Brumptomyia) were collected. There were significant differences in the mean number of sand flies caught with the 11 traps; CDC-I was (P  =  0.0000) more effective than the other traps. Other traps exhibited the following results: CDC-W (17.46%), CDC-B (15.68%), CDC-G (14.89%), and CDC-R (14.30%). The relative abundance of different species varied according to trap types used, and the CDC-I trap attracted more specimens of the known vectors of Leishmania spp., such as like Lutzomyia cruciata, Lu. shannoni, and Lu. ovallesi. Disney trap captured more specimens of Lu. olmeca olmeca. Based on abundance and number of species, CDC light traps and Disney traps appeared to be good candidates for use in vector surveillance programs in this endemic area of Mexico.

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In South America, cutaneous leishmaniasis is the most frequent clinical form of leishmaniasis. Bolivia is one of the countries with higher incidence, with 33 cases per 100,000 individuals, and the disease is endemic in 70% of the territory. In the last decade, the number of cases has increased, the age range has expanded, affecting children under 5 years old, and a similar frequency between men and women is found. An entomological study with CDC light traps was conducted in three localities (Chipiriri, Santa Elena and Pedro Domingo Murillo) of the municipality of Villa Tunari, one of the main towns in the Chapare province (Department of Cochabamba, Bolivia). A total of 16 specimens belonging to 6 species of the genus Lutzomyia were captured: Lu. aragaoi, Lu. andersoni, Lu. antunesi, Lu. shawi, Lu. yuilli yuilli and Lu. auraensis. Our results showed the presence of two incriminated vectors of leishmaniasis in an urbanized area and in the intradomicile. More entomological studies are required in the Chapare province to confirm the role of vector sand flies, the intradomiciliary transmission of the disease and the presence of autochthonous cases of cutaneous leishmaniasis.

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The objective of the project was to study the entomofauna associated to the sugar-cane commercial cultivation in União region, state of Piauí, Brazil. The insects were collected with light traps, model Luiz de Queiroz supplied with fluorescent lamps, ultraviolet, model F15 T8 BL posicioned in a height of 1,5m, at the geographic coordinates 21 22 30 S and 48 13 0 W. The traps were turned on at 18:00 and turned of 6:00 of the day after, from December, 2006 to December, 2007, coming down 52 samples. Weekly 287 species that were evaluated by using faunistic analysis of dominance, frequency, constancy and abundance, with 30 species distinguishing in these indexes. Astaena sp with 3.313 specimen collected in 44 from the 52 samples, Cyclocephala sp2 with 2415 collected in 51 from the 52 samples and Linepithema humile with 2299 in 18 samples.

O presente trabalho teve como objetivo estudar a entomofauna associada ao cultivo comercial de cana-de-açúcar, no município de União, Estado do Piauí. Os insetos foram coletados com armadilha luminosa, modelo Luiz de Queiroz, provida de lâmpada F 15 T 8 BL. As coletas foram realizadas uma vez por semana, com a armadilha sendo ligada às 18:00 horas e desligada às 6:00 horas do dia seguinte, no período de dezembro de 2006 a dezembro de 2007, totalizando 52 coletas. Foram coletadas 287 espécies, submetidas à análise faunística de dominância, freqüência, abundância e constância, com 30 espécies se sobressaindo nestes índices. Astaena sp, apresentando 3.313 indivíduos, coletados em 44 das 52 coletas, Cyclocephala sp2 com 2.415 coletados em 51 das 52 e Linepithema humile com 2.299 presentes em 18 coletas.

RESUMO

The objective of the project was to study the entomofauna associated to the sugar-cane commercial cultivation in União region, state of Piauí, Brazil. The insects were collected with light traps, model Luiz de Queiroz supplied with fluorescent lamps, ultraviolet, model F15 T8 BL posicioned in a height of 1,5m, at the geographic coordinates 21 22 30 S and 48 13 0 W. The traps were turned on at 18:00 and turned of 6:00 of the day after, from December, 2006 to December, 2007, coming down 52 samples. Weekly 287 species that were evaluated by using faunistic analysis of dominance, frequency, constancy and abundance, with 30 species distinguishing in these indexes. Astaena sp with 3.313 specimen collected in 44 from the 52 samples, Cyclocephala sp2 with 2415 collected in 51 from the 52 samples and Linepithema humile with 2299 in 18 samples.

O presente trabalho teve como objetivo estudar a entomofauna associada ao cultivo comercial de cana-de-açúcar, no município de União, Estado do Piauí. Os insetos foram coletados com armadilha luminosa, modelo Luiz de Queiroz, provida de lâmpada F 15 T 8 BL. As coletas foram realizadas uma vez por semana, com a armadilha sendo ligada às 18:00 horas e desligada às 6:00 horas do dia seguinte, no período de dezembro de 2006 a dezembro de 2007, totalizando 52 coletas. Foram coletadas 287 espécies, submetidas à análise faunística de dominância, freqüência, abundância e constância, com 30 espécies se sobressaindo nestes índices. Astaena sp, apresentando 3.313 indivíduos, coletados em 44 das 52 coletas, Cyclocephala sp2 com 2.415 coletados em 51 das 52 e Linepithema humile com 2.299 presentes em 18 coletas.