Thermal preferences and limits of Triatoma brasiliensis in its natural environment - Field observations while host searching

• Published in: Memórias do Instituto Oswaldo Cruz Vol. 110; no. 6; pp. 793 - 796
• Main Authors: Catalá, Silvia, Bezerra, Claudia Mendonça, Diotaiuti, Lileia
• Format: Journal Article
• Language: English
• Published: Brazil Fundação Oswaldo Cruz, Fiocruz 01.09.2015; Instituto Oswaldo Cruz, Ministério da Saúde; Fundação Oswaldo Cruz (FIOCRUZ)
• Subjects: Animals; Body Temperature - physiology; Brazil; Chagas disease; Chagas Disease - transmission; Ecosystem; Feeding Behavior - physiology; Geologic Sediments - classification; Hot Temperature; Infrared Rays; Insect Vectors - classification; Insect Vectors - physiology; PARASITOLOGY; Photoperiod; Rural Population; Seasons; Sunlight; thermal limits; Triatoma - classification; Triatoma - physiology; Triatominae; TROPICAL MEDICINE; Brazil; Chagas disease; Triatominae; thermal limits
• ISSN: 1678-8060; 0074-0276; 0074-0276; 1678-8060
• DOI: 10.1590/0074-02760150234

The goal of this work was to explore the thermal relationship between foraging Triatoma brasiliensis and its natural habitat during the hottest season in the state of Ceará, Brazil. The thermal profiles were determined using infrared analysis. Although the daily temperature of rock surfaces varied in a wide range, T. brasiliensis selected to walk through areas with temperatures between 31.7-40.5ºC. The temperature of T. brasiliensis body surface ranged from 32.8-34.4ºC, being higher in legs than the abdomen. A strong relationship was found between the temperature of the insect and the temperature of rock crevices where they were hidden (r: 0.96, p < 0.05). The species was active at full sunlight being a clear example of how the light-dark rhythm may be altered, even under predation risk. Our results strongly suggest a thermal borderline for T. brasiliensis foraging activity near 40ºC. The simultaneous determination of insect body and rock temperatures here presented are the only obtained in natural habitats for this or other triatomines.