Reload capacity of Brindley´s glands and its relationship with the degree of fasting in the blood-sucking bug Triatoma infestans

PALOTTINI F.; MANRIQUE, G.

Viçosa

Encuentro; VI Encontro Brasileiro de Ecología Química; 2009

Reload Capacity of Brindley´s Glands and its Relationship with the Degree of Fasting in the Blood-Sucking Bug Triatoma infestans Palottini F1., Manrique G1. 1Laboratorio de Fisiología de Insectos. Dpto. Biodiversidad y Biología Experimental. Universidad de Buenos Aires. Ciudad Universitaria. Pabellón II. florpal@bg.fcen.uba.ar When Triatoma infestans adults are disturbed, metasternal and Brindley’s glands discharge their volatiles. During disturbance, it is possible to observe the secretion from Brindley´s glands and to smell a characteristic pungent odour. The aim of this study was to determine whether the capacity to release the secretion from Brindley’s glands is related to the degree of fasting. T. infestans females and males with different degree of fasting, were fed or not and disturbed weekly by pressing one of their legs with forceps. When disturbed, each bug was observed under a stereomicroscope and the glands’ state was inferred qualitatively as: full, partially full or empty. We considered that the glands were filled when the secretion was observed near its opening, partially filled when no secretion was observed but the presence of odour was perceived and empty when both secretion and odour were not observed nor perceived. Results showed that 87% of 1-week old, unfed adults presented filled glands and 13% partially filled ones (without differences between sexes). As fasting time increased, the amount of unfed insects with filled glands decreased (from 37.5 to 0%), while the proportion of insects with empty glands increased (from 2.8 to 73.7%). On the other hand, the week per week estimation of glands´ filling dynamics showed that unfed adults were not able to reload their glands and during each disturbance the occurrence of secretion or odour emission decreased. On the contrary, up to 71.4% of fed insects probably reloaded their glands since further secretion was observed. These results suggest that glands filling dynamics depend on feeding. The lengthy fasting of adults would restrict the reload capacity of Brindley`s glands for an eventual secretion release during a new disturbance event. Acknowledgements: ANPCyT (PICT 01191), CONICET and Universidad de Buenos Aires.