The pleasure of eating in haematophagous insects.

BARROZO RB

Huerta Grande Cordoba

Simposio; II Latin American Association of Chemical Ecology; 2012

Food taste delivers reliable information about the quality of feeding sources. In phytophagous animals, for example, bitter substances are generally toxic and poorly sweetened sources indicate poor nutritious diets. So, food quality recognition followed by an associated decision making will have important physiological consequences for animals. Triatomine insects feed on blood from vertebrates. Once they find a potentially suitable host (followed by olfactory and thermal cues principally), they pose over the host skin (skin recognition phase) and pierce it by moving their mouthparts until a venule or arteriole is found. Next, they pump a small quantity of blood initiating the sampling phase of food. If the sampled diet fulfils bug’s feeding requirements, the insect will continue with the ingestion of food. Up to now, no information is available in literature about fine discrimination of gustatory preferences in triatomines and how different cues might be modulating the decision making during the skin recognition phase and the sampling phase. We started filling a gap of knowledge on the ultrastructure of taste organs and their physiological and behavioural responses to relevant substances of bugs’ diet. Taste receptors located in the antenna and in the epipharingeal organ (internal receptors placed in the alimentary canal) seems to become crucial in terms of recognition and assessment of food quality. Taste perception in triatomine bugs leading to aversiveness or acceptance of a food source is dependent on chemical identity (salts, alkaloids “bitter” compounds, ATP) and other chemical qualities like concentration, osmolarity, pH, ionic composition.