Abstract

RUBIO G, JOSÉ DAVID  and  ACUNA Z, JOSÉ RICARDO. Comparative anatomy of the digestive tract in imagos of the weevil complex (Coleoptera: Curculionidae) associated with plantain plantations. . Rev. Colomb. Entomol. [online]. 2006, vol.32, n.1, pp.67-72. ISSN 0120-0488.

Using optical microscopy, the digestive tract of imagos of Cosmopolites sordidus Germar, Metamasius hemipterus sericeus L. and Metamasius hebetatus Gyllenhal, which are considered pests of plantain and banana, was studied. These beetles have a typical digestive system divided into three regions: stomodeum, mesenteron and proctodeum. These regions have a tubular form and are associated with numerous tracheae that facilitate gas exchange. The stomodeum initiates in the preoral cavity and continues with the pharynx and the esophagus, with little morphological differentiation, but with the presentation of external muscles. The crop is a stretched esophageal region, covered by circular muscles. Adjacent to this is the proventriculus that has cuticular internal projections that occlude the lumen. The mesenteron is divided into two ventricles, the anterior with an ovoid shape and the posterior with a stretched shape, each presenting abundant gastric caeca. The proctodeum initiates in the pyloric valve, continuing with the ileum and colon with a duct leading to the anus; this region has various folds in which the reproductive organs are inserted. In all three species, six long Malpighian tubules were observed, which initiate in the pylorus and extend to the middle region of the colon, tightly adhered to the alimentary canal. This work contributes to a better understanding of the structure and function of the digestive tract, describing and analyzing the morphology in these curculionid species.

Keywords : Cosmopolites ; Metamasius ; pest of plantain; internal morphology.

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