Abstract
The salivary secretions of leafhoppers are considerably important for their toxic effect on the host plant, and concerning the transmission of plant viruses. In the present paper morphological and histological studies were made on the salivary glands of the rice plant leafhoppers in order to help to throw light on their functions. Results obtained were summarized as follows: -
(1) The salivary glands were consisted of a pair of principal gland and accessory gland, and their conducting parts. In N. cincticeps and I. dorsalis, the principal gland was a compact mass made up of six kinds of secretory cells, and bilobed. It was characterized by the much smaller anterior lobe and the six large III-cells of the posterior lobe. The accessory gland was extremely short and bent tubular gland. In L. striatellus, S. furcifera and N. lugens, the principal gland was an aggregate body consisted of eight kinds of follicle that were made up of a small number of secretory cell. The accessory gland was a bi-cellular gland being somewhat constricted spherical in shape.
(2) With histological staining it was demonstrated that each kind of secretory cells in N. cincticeps and follicle of L. striatellus had distinctly different cytological structures suggesting their different functions (Text-Figs. 2 and 4; Tables 1 and 2). It was considered at least that the IV-cells of N. cincticeps and the A-follicle of L. striatellus produced digestive enzymes, and that the V-cells of N. cincticeps served as one of the sources of the sheath material.
(3) In N. cincticeps the accessory gland was divided into two portions, the head and tail portions. The tail portion was resembled in structure to the Malpighian tubules, and it was hypothetically assumed that this portion absorbed selectively certain non-protein solutes from hemolymph. In L. striatellus the accessory gland was regarded as a main source of the sheath material.
(4) Both the principal as well as the salivary ducts seemed to perform some function other than a mechanical transport of the secretions.
