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Chagas disease is caused by the protozoan parasite Trypanosoma cruzi (Chagas, 1909). One of the primary vectors of T. cruzi in South America is Triatoma infestans (Klug, 1834). This triatomine species is distributed across a huge latitudinal gradient, inhabiting domiciliary , peridomiciliary , and wild environments. Its wide geographic distribution provides an excellent opportunity to study the relationships between environmental gradients and intraspecific morphological variation. In this study, we investigated variations in wing size and shape in T. infestans across six ecoregions. We aimed to address the following questions: How do wing size and shape vary on a regional scale, does morphological variation follow specific patterns along an environmental or latitudinal gradient, and what environmental factors might contribute to wing variation? Geometric morphometric methods were applied to the wings of 162 females belonging to 21 T. infestans populations, 13 from Argentina (n = 105), 5 from Bolivia (n = 42), and 3 from Paraguay (n = 15). A comparison of wing centroid size across the 21 populations showed significant differences. Canonical Variate Analysis (CVA) revealed significant differences in wing shape between the populations from Argentina, Bolivia, and Paraguay, although there was a considerable overlap, especially among the Argentinian populations. Well-structured populations were observed for the Bolivian and Paraguayan groups. Two analyses were performed to assess the association between wing size and shape, geographic and climatic variables: multiple linear regression analysis (MRA) for size and Partial Least Squares (PLS) regression for shape. The MRA showed a significant general model fit. Six temperature-related variables, one precipitation-related variable, and the latitude showed significant associations with wing size. The PLS analysis revealed a significant correlation between wing shape with latitude, longitude, temperature-related, and rainfall-related variables. Wing size and shape in T. infestans populations varied across geographic distribution. Our findings demonstrate that geographic and climatic variables significantly influence T. infestans wing morphology.

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BACKGROUND: Chagas Disease (CD) affects 6-7 million people worldwide and is related to poverty-promoting conditions. Chronic asymptomatic cases are mostly invisible to health systems. Aiming (1) to translate CD discoveries into education/information practices to raise alertness and empowerment of affected people; and (2) to perform an active search of CD cases, articulating intersectoral actions to improve the access of infected people to the local health service for the treatment of CD; our research group developed and tested under field conditions as innovative social technology: an itinerant education interdisciplinary setting named "Chagas Express XXI" (CE21). METHODOLOGY: CE21 was created as an "imaginary train" with ~40 ArtScience workshops, games, laboratory activities and conversation circles. An entry/exit plus six activity modules combined associations of affected people, microscopic observations, One Health education, and wellness activities. CE21 was conceived as a social technology, since all the processes were co-created with CD patients and inter-sector local partners. Descriptive statistics showed quantitative data collected throughout the expeditions (CD knowledge, serological results). Qualitative data accessed the public perceptions about the education activities. PRINCIPAL FINDINGS: CE21 was exhibited in local educational institutions (schools, universities) in four cities, engaging 2,117 people that evaluated the 41 activities carried out. Citizens and health professionals enjoyed acquisition of information related to blood, parasites, vectors, reservoirs, environmental changes, and social determinants of CD. Further, local legacies of 600 participants volunteer for health promotion groups and CD associations, local empowerment groups to fight for better health conditions, and 05 mural paintings. We observed that 81% of the participants ignored the possibility of treating CD while 52% of the participants requested a blood test for CD showing seropositivity in 20% of them. CONCLUSIONS: CE21 is a social technology potentially useful for health and science education and active search of asymptomatic CD chronic cases. Moreover, this technology may be adapted to understand and to cooperate in other potentially epidemic situations, especially NTDs related.

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Morphology of cimicid eggs are scarce, and this is the first record for the genus Ornithocoris Pinto, 1927 (Hemiptera: Cimicidae), using scanning electron microscopy (SEM). This genus comprises two species: Ornithocoris toledoi Pinto, 1927 (Hemiptera: Cimicidae) and Ornithocoris pallidus (Usinger, 1959). The eggs of O. pallidus are ellipsoid, and an evident 'lateral flattening', which may give clear asymmetry from the longitudinal axis. The exochorion of the body of the egg and operculum of O. pallidus present spherical or polygonal structures in relief, and pseudomicropyles on the border of the operculum, both differing from Cimex lectularius. The internal face of the operculum is smooth and the border also presented three layers. It was not possible to observe micropyles in the egg of O. pallidus. Bed bugs have a great psychological impact on people, and some people can develop a more or less severe allergic reaction against the bite. Successful control of bed bugs needs serious organization. Studies on egg morphology will add more information to assist in taxonomy studies of O. pallidus and can serve as a basis for control studies because eggs are resistant to insecticides.

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Triatoma sherlocki Papa, Jurberg, Carcavallo, Cerqueira & Barata was described in 2002, based on specimens caught in the wild in the municipality of Gentio do Ouro, Bahia, Brazil. In 2009, nymphs and adults were detected inside homes and sylvatic specimens were positive for Trypanosoma cruzi (Chagas). No information on the bionomics of T. sherlocki exists, although such data are considered essential to estimate its vector and colonization potential in domestic environments. Herein, the biological cycle of T. sherlocki was studied based on 123 eggs, with nymphs and adults fed on Mus musculus (Linnaeus). Nymphal development time phases, number of meals consumed, and stage-specific mortality rates were analyzed. Survival time under starvation conditions was measured between ecdysis and death among 50 nymphs (first to fifth instar) and 50 male and female adults. The median development time from egg to adult was 621.0 (CI: 489-656) d. The number of meals consumed ranged from 1 to 20 for nymphs of the first to fifth instar. The fifth instar showed the greatest resistance to starvation, with a mean of 156.5 d. The high number of meals consumed by T. sherlocki favored infection with and transmission of T. cruzi. The full development of this species under laboratory conditions with a low mortality rate indicates that this vector presents biological characteristics that may contribute to its adaptation to artificial human ecotopes. Its high resistance to starvation emphasizes the importance of entomological surveillance for this species.

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Because of the morphological and morphometric variation of testicular follicles in different genera of the subfamily Triatominae, it was of interest to associate those parameters with the different medial pronotal band patterns (wide and narrow) found in Rhodnius brethesi (Matta) (Hemiptera: Reduviidae). This is a wild species often associated with Leopoldina piassaba Wallace (Arecales: Arecaceae) palm, with a geographical distribution restricted to the Amazon region. The specimens used were from the state of Amazonas, and were kept under conditions of 29 ± 1 °C, 80 ± 5% RH, 12:12 L:D photoperiod, and were fed weekly on blood from Swiss mice. Three-day-old fasting males were separated in accordance with the patterns of the medial pronotal band, dissected, and the testicles removed. After removal of the testicular membrane, the follicles were spread, drawn by camera lucida, and measured. The results showed that the testis of R. brethesi consists of seven follicles, divided into two groups by length; two long and five short. In specimens with a wide medial pronotal band, the long follicles were 5.4 mm in length, but in specimens with a narrow medial band, the long follicles were 5.64 mm in length. The difference was significant. The short follicles were not different in length, suggesting the presence of a possible complex "brethesi" in the Amazon region.

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The bedbugs Cimex lectularius and Cimex hemipterus are obligate hematophages in all their nymphal instars as well as in the adult stage. The efficiency with which the insects obtain blood from their hosts is directly related to their population dynamics. In the present study we compared the feeding process and salivary content in individuals of these two species when fed on different blood sources or host sites, using a cibarial pump electromyogram. Females ingested more blood than males but needed longer contact time with the host to complete the meal. The bedbug C. lectularius was more efficient than C. hemipterus in obtaining blood from mice and pigeons. With regard to the feeding site on mice, it was easier for the insects to obtain blood from the skin of the belly than that of the back. Individuals of C. hemipterus were able to maintain the cibarial pump functioning at higher frequencies for longer periods when fed on pigeons treated with anticoagulant. Although saliva from C. lectularius contained more hemeproteins and showed more anti-clotting activity its total protein content was similar to that of C. hemipterus. Overall, C. lectularius obtains a bloodmeal more efficiently from its hosts, which may have enabled this species to reach higher levels of infestation than C. hemipterus.

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Megaselia scalaris (Loew) is a cosmopolitan and synanthropic scuttle fly, eclectic in its feeding habits and acts as detritivore, parasite, facultative parasite, and parasitoid. Here we report for the first time M. scalaris infesting laboratory colonies of Triatoma brasiliensis Neiva, the most important Chagas disease vector in semiarid areas of Brazil. M. scalaris larvae were found feeding inside bugs; pupae were found in the esophagus and intestinal regions of T. brasiliensis through dissection. Other relevant information about this finding is also described in this note, including some preventive measures to avoid laboratory colonies infestations.

Megaselia scalaris (Loew) é uma mosca cosmopolita, sinantrópica e eclética quanto aos seus hábitos alimentares, tendo sido descrita como detritívora, parasita, parasita facultativa e parasitóide. Nesta nota, registra-se pela primeira vez, M. scalaris infestando colônias de laboratório de Triatoma brasiliensis Neiva, o mais importante vetor da doença de Chagas no semi-árido brasileiro. Larvas de M. scalaris foram encontradas alimentando-se dos órgãos internos dos triatomíneos; pupas foram encontradas na região intestinal e esofagiana de exemplares de T. brasiliensis dissecados. Outras informações relevantes sobre o achado são descritas nesta nota, bem como medidas preventivas para evitar infestações por M. scalaris em colônias de triatomíneos.

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Megaselia scalaris (Loew) is a cosmopolitan and synanthropic scuttle fly, eclectic in its feeding habits and acts as detritivore, parasite, facultative parasite, and parasitoid. Here we report for the first time M. scalaris infesting laboratory colonies of Triatoma brasiliensis Neiva, the most important Chagas disease vector in semiarid areas of Brazil. M. scalaris larvae were found feeding inside bugs; pupae were found in the esophagus and intestinal regions of T. brasiliensis through dissection. Other relevant information about this finding is also described in this note, including some preventive measures to avoid laboratory colonies infestations.

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