The Anatomy and Ultrastructure of the Digestive Tract and Salivary Glands of Hishimonus lamellatus (Hemiptera: Cicadellidae).

In recent years, we found that Hishimonus lamellatus Cai et Kuoh is a potential vector of jujube witches'-broom phytoplasma. However, little is known about the anatomy and histology of this leafhopper. Here, we examined histology and ultrastructure of the digestive system of H. lamellatus, both by dissecting and by semi- and ultrathin sectioning techniques. We found that the H. lamellatus digestive tract consists of an esophagus, a filter chamber, a conical midgut and midgut loop, Malpighian tubules, an ileum, and a rectum. Furthermore, both the basal region of the filter chamber epithelium and the apical surface of the midgut epithelium have developed microvilli. We also identify the perimicrovillar membrane, which ensheaths the microvilli of midgut loop enterocyte, and the flame-like luminal membrane, which covers the microvilli of the conical midgut epithelium. In addition, H. lamellatus has the principal and accessory salivary glands. Our observations also showed that the endoplasmic reticulum, mitochondria, and secretory granules were all highly abundant in the secretory cells of the principal salivary glands, while the accessory glands consist of only one ovate or elbow-like acinus. We also briefly contrast the structure of the gut of H. lamellatus with those of other leafhopper species. These results intend to offer help for the future study on the histological and subcellular levels of phytopathogen-leafhopper relationships, including transmission barriers and the binding sites of pathogens and other microorganisms within their leafhopper vectors.