title: Circadian rhythm of behavioural responsiveness to carbon dioxide in the blood-sucking bug Triatoma infestans (Heteroptera: Reduviidae).
abstract: The temporal modulation of the behavioural response to carbon dioxide and its chronobiological basis were investigated in larvae of Triatoma infestans. We analysed the orientation towards CO(2) of insects kept under three different illumination regimes: (1) 12 h light/12 h darkness cycles (L/D), (2) constant darkness (D/D) and (3) constant light (L/L). When maintained under L/D conditions, insects exhibited an oriented response towards airstreams added with 1500 ppm of CO(2) during the first hours of the scotophase only. Bugs maintained under D/D also showed a positive orientation response towards CO(2) during the first hours of the subjective night, while bugs kept under L/L did not show a rhythmic oriented behaviour. Thus, T. infestans displayed a daily rhythm of orientation towards CO(2) (i.e. a potential food source) only at the beginning of the scotophase. The persistence of the rhythm under constant darkness reveals the existence of an endogenous circadian control of this behaviour.
authors.affiliation: Laboratorio de Fisiología de Insectos, Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, C1428EHA Buenos Aires, Argentina. rbarrozo@bg.fcen.uba.ar
authors.forename: Romina B
authors.initials: RB
authors.lastname: Barrozo
authors.forename: Sebastián A
authors.initials: SA
authors.lastname: Minoli
authors.forename: Claudio R
authors.initials: CR
authors.lastname: Lazzari
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D002245:Carbon Dioxide; D002633:Chemotaxis / Q000502:physiology; D002940:Circadian Rhythm / Q000502:physiology* / Q000528:radiation effects; D005247:Feeding Behavior / Q000502:physiology* / Q000528:radiation effects; D006790:Host-Parasite Interactions / Q000502:physiology / Q000528:radiation effects; D006801:Humans; D008027:Light; D009949:Orientation / Q000502:physiology; D010465:Perception / Q000502:physiology*; D014224:Triatoma / Q000502:physiology*
chemical_list: D002245:Carbon Dioxide