Abstract

The morphological features of the columnar epithelial cell in the midgut of Diatraea saccharalis larvae were studied by transmission electron microscopy. There are ultrastructural differences in the columnar cell morphology depending on their localization along the midgut. The apical columnar cell surface exhibit protrusions besides the conspicuous microvilli related to microapocrine vesicles; these cytoplasmic protrusions contain many organelles and they increase in number and size from the anterior to the posterior midgut regions. The mitochondria distribution is also variable. They are few in the apical surface of the anterior región and numerous in the posterior one; the opposite is observed in the basal cytoplasm, where the mitochondria are more abundant in the anterior region. Our results show that the morphological variations in the columnar cell morphology along the midgut of the sugarcane borer are similar to the ones described for other Lepidoptera species. The secretion carried out by the midgut columnar cell may be related to both the microapocrine process and cytoplasmic protrusion release.