Department of Zoology, University College, Trivandrum-695 034, Kerala (India).
Endocrine cells reminiscent of α and β cells of the islets of Langerhans in vertebrates were identified in the midgut epithelium of the larvae of Oryctes rhinoceros Linn. employing conventional staining techniques. They occur singly, interspersed among the columnar and regenerative cells of the epithelium. They are a few in number as compared to other cells and are mostly present in the anterior part of the midgut. The anterior midgut epithelium is found to be the source of a factor, probably hormone, stimulating digestive enzyme release from the midgut tissue.
