| The present study use the light and transmission electron microscope to study the salivary gland, alimentary canal and Malpighian tubule of Cicadomorpha adults and the associations between these organs and their related functions respectively, based on the comparative morphology of 13 species representing three superfamilies. The morphology, function and enlightenment significance of the phylogeny is discussed; and the results are listed as follows:1. The salivary glands of Cicadomorpha consist of principal and accessory glands, and the morphology of them exhibit great variations among superfamilies:(1) The principal glands of the salivary glands of Membracoidea are acinous, and the duct of the accessory salivary gland is short and thick. The shape, thickness and length of the pricinpal glands vary among species.(2) The principal glands of salivary glands of the representatives among different subfamilies (Cryptotympana atrata, Platypleura kaempferi, Meimuna mongolica, Hyalessa maculaticollis, Karenia caelatata and Leptopsalta sp.) comprise of anterior and posterior lobes. One duct connects the anterior and the posterior lobes. The accessory gland consists of accessory salivary tube (AST), gular gland and accessory salivary duct (DAS). The accessory gland connects the efferent salivary duct at the base of the posterior lobe. Two efferent salivary ducts merge into a common duct, which connecting with the salivary syringe. However, there is also great variations on the morphology of the salivary glands among subfamilies: the salivary glands of the Leptopsalta sp. are dissimilar to those of the aformentioned species, the former with fewer lobes of principal glands than those of the latter, and the anterior lobes are long, thick and straight, while the posterior lobes are short, thin and round.(3) The salivary glands of Clovia conifer in Cercopoidea also comprises of principal and accessory gland. All the anterior lobes of the principal gland are acinous, and the posterior lobes with two types of lobes: one is acinous, and the other is rod-like. The duct of accessory gland is very long and connects with efferent salivary duct, which combine to be a common salivary duct and connects with salivary syringe. All the cells of the anterior lobes contain numerous secretory granules and well developed rough endoplasmic reticulum. Some lobes of anterior and posterior lobes contain microorganisms. The cell of the accessory gland duct with well developed basal infoldings. The accessory gland body contains lots of secretory vesicles and rough endoplasmic reticulum. The cell of the common duct of salivary gland has numerous secretory vesicles.2. The alimentary canal of Cicadomorpha comprises of foregut (pharynx, esophagus), filter chamber, midgut (conical segment and tubular midgut) and hindgut (ileum and rectum). The esophagus is an elongate tube with thick intima. The anterior midgut, posterior midgut, base of Malpighian tubule and ileum are enveloped by membranous sheath, thus form filter chamber, which is the specialized structure of alimentary canal. The cell of the filter chamber contains large amounts of mitochondria, well developed basal infoldings and microvilli. The conical segment inflates to be a well developed sac, the cell of which with well developed basal infoldings. The cell of the tubular midgut with microorganisms and well developed basal infoldings. The hindgut comprises of long ileum and inflated rectum. Muscles of the hindgut are well developed, and the cell of hindgut with contains numerous microorganisms, and the basal membrane is thin. The ileum and the Malpighian tuules are zigzagged in layout. The cell of the Malpighian tubules contains lots of mitochomdria, and the microvilli are well developed. Although the morphology and layout of the alimentary canal in Cicadomorpha are very similar, the morphology of filter chamber, conical segment, rectum and the location of ileum connecting with the filter are vary among families:(1) Cicadoidea: the filter chamber is rod-like in shape and bent to some extent; the conical segment inflates into a sac, which is 1.5 to 2.0 times longer than filter chamber; the ileum emerges at the apical part of the filter chamber; the rectum is well inflated, and there is a membranous sac at the base of the rectum.(2) Cercopoidea: the filter chamber inflates into a big sac, which is not bent; the conical segment is inflated, and the length of which is about 1.5 times of filter chamber; the ileum arises at the halfway along the filter chamber; the rectum inflated a bit, and at the base of which with membranous sac.(3) Membracoidea: the filter chamber is small and round in shape; the conical segment is extremely developed, and about 4.0 times of the filter chamber; the ileum emerges at the distal end of the filter chamber; the rectum inflated to be a pear-shaped structure, and without membranous sec at the base of the rectum.The alimentary canal of the Cicadomorpha could be divided into two types, according its morphology: Cicadoidea and Cercopoidea share the same type, and Membracoidea the other (diagrams are provided for each type)3. The morphology and number of Malpighian tubules exhibit certain similarity in Cicadomorpha. And the morphology of the Cicadoidea and Cercopoidea is much similar. But there are also some differentiations of each segment of the Malpighian tubules among families:(1) Cicadoidea and Cercopoidea: the MT1 and MT2 are smooth, and the latter is thinner and longer than that of the foemer. The MT3 is the longest and the thickest one among the four segments, and nudulose in appearance. The MT4 is wavy in appearance.. (2) Membracoidea: the MT1 is short and smooth. The MT2 is long and nodulose in appearance. The MT3 inflates to be a glandular obviously. The MT4 constricts at the base, and thinner than that of the MT2, and wavy in appearance.The Malpighian tubule of the Cicadomorpha could be divided into six segment, based on the comparative study of morphology of the Malpighian tubules of the three families.i.e., filter chamber Malpighian tubule, terminal Malpighian tubule, and the other four regions between the aforementioned two regions (four diagrams are provided for the partition of the Malpighian tubules in Cicadomorpha adults).The results of this investigation suggests that the differentiation and similarities among salivary glands, alimentary canals and Malpighian tubules within different taxa of Cicadomorpha adults and the association between these organs and their related functions not only provide support proofs and identification characteristics to monophyletic of each group in Cicadomorpha, but also provide meaningful implication and proofs of morphology, ethology, ecology and biology to the phylogeny of Cicadomorpha, i.e., Cicadoidea is the sister group to Cercopoidea, due to their certain structural and functional similarities, especially displayed by their salivary glands, Malpighian tubules and alimentary canals, which is closely related to the distinct cryptobiotic life modes of their immatures. |
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