Triatoma infestans is the main vector of Chagas disease in the southern cone of South America. This species is well adapted to living in rural houses and structures used for housing domestic animals (peridomestic habitats). In this study, we evaluated the relationship between the source of blood consumed by adults of T. infestans collected from different peridomestic habitats from two localities from Cruz del Eje department (Córdoba, Argentina) and their nutritional and reproductive status. In each individual, the ratio between body weight and total body length was used as an indicator of nutritional status (NS). The presence of sperm in spermathecae and the number of chorionated oocytes in ovaries and oviducts were considered indicators of reproductive status (RS) of females. The feeding source in the promesenteron of male and female insects was identifed using anti-chicken, anti-goat, anti-human and anti-dog antisera. Chicken coops were the main peridomestic structure present in the study area as well as the peridomestic sites with the highest percentage of T. infestans. Insects collected from the different peridomestic structures showed a NS between 8 and 15 mg/mm. Of the evaluated females, 35.7% presented chorionated oocytes. Food profle analyses revealed that chicken was the main blood source. Independently of the blood source, the triatomines presented a NS between 8 and 15 mg/mm. No specimens feeding exclusively on human blood were found; nevertheless, of 31.48% of insects feeding on mixed blood sources, 59% included human blood. All T. infestansspecimens that included human blood in the mixed blood source were collected from chicken coops and storerooms located in a 12-m area around domiciles. Human blood present in mixed blood meal of adult insects suggests that T. infestansmoves from domiciles to peridomicilies and vice versa.

Triatoma infestans es el principal vector de la enfermedad de Chagas en el Cono Sur de Sudamérica. Esta especie está bien adaptada a vivir en el domicilio y estructuras utilizadas para albergar animales domésticos (hábitats peridomésticos). En este trabajo evaluamos la relación entre la fuente de sangre consumida por los adultos de T. infestans recolectados de diferentes hábitats peridomésticos de dos localidades del departamento de Cruz del Eje (Córdoba, Argentina) y su estado nutricional y reproductivo. En cada individuo, la relación entre el peso y la longitud corporal total se utilizó como un indicador del estado nutricional (EN). La presencia de espermatozoides en espermatecas y el número de ovocitos corionados en ovarios y oviductos se consideraron indicadores del estado reproductivo (ER) de las hembras. La fuente de alimentación en el promesenterón de insectos machos y hembras se identifcó utilizando antisueros anti-gallina, anti-cabra, anti-humano y anti-perro. Los gallineros fueron las principales estructuras peridomésticas presentes en el área de estudio, así como los sitios con el mayor porcentaje de T. infestans. Los insectos recolectados en las diferentes estructuras peridomésticas mostraron un EN entre 8 y 15 mg / mm. De las hembras evaluadas, el 35,7% presentó ovocitos corionados. Los análisis del perfl alimentario revelaron que las gallinas fueron la principal fuente de sangre. Independiente de la fuente de sangre los triatominos presentaron EN entre 8 y 15 mg / mm. No se encontraron ejemplares alimentados exclusivamente con sangre humana; sin embargo, del 31,48% de los insectos que se alimentaron de fuentes de sangre mixtas, el 59% incluía sangre humana. Todas las muestras de T. infestans que incluían sangre humana en la fuente de sangre se recolectaron en gallineros y depósitos ubicados en un área de 12 m alrededor de los domicilios. La sangre humana presente en las fuentes de alimentación mixta sugiere que T. infestans se mueve de los domicilios a los peridomicilios y viceversa.

The metabolism of lipids and carbohydrates related to flight activity in Panstrongylus megistus was investigated. Insects were subjected to different times of flight under laboratory conditions and changes in total lipids, lipophorin density and carbohydrates were followed in the hemolymph. Lipids and glycogen were also assayed in fat body and flight muscle. In resting insects, hemolymph lipids averaged 3.4 mg/ml and significantly increased after 45 min of flight (8.8 mg/ml, P < 0.001). High-density lipophorin was the sole lipoprotein observed in resting animals. A second fraction with lower density corresponding to low-density lipophorin appeared in insects subjected to flight. Particles from both fractions showed significant differences in diacylglycerol content and size. In resting insects, carbohydrate levels averaged 0.52 mg/ml. They sharply declined more than twofold after 15 min of flight, being undetectable in hemolymph of insects flown for 45 min. Lipid and glycogen from fat body and flight muscle decreased significantly after 45 min of flight. Taken together, the results indicate that P. megistus uses carbohydrates during the initiation of the flight after which, switching fuel for flight from carbohydrates to lipids.

Lipids and glycogen in fat body as well as the modifications in the wet weight of this organ were evaluated in an unfed insect, Dipetalogaster maximus, on day 5 after adult ecdysis (time 0) and during a 30-day period after ingestion of blood meal. Total lipids, high density lipophorin (HDLp), carbohydrates, total proteins and uric acid were determined in the hemolymph during the same period. Fat body wet weight was maximum on day 10 post-feeding and represented on day 30 only 42% of the maximum weight. Lipids stored in the fat body increased up to day 15 reaching 24% of the total weight of tissue. Glycogen was maximum on day 20, representing approximately 3% of the fat body weight. HDLp represented at all times between 17-24% of the total proteins, whose levels ranged between 35 and 47 mg/ml. Uric acid showed at 20, 25 and 30 days similar levels and significantly higher than the ones shown at days 10 and 15. Hemolymphatic lipids fluctuated during starvation between 3-4.4 mg/ml and carbohydrates showed a maximum on day 15 after a blood meal, decreasing up to 0.26 mg/ml on day 25. The above results suggest that during physiological events such as starvation, the availability of nutrients is affected, involving principally the fat body reserves