title: [Histology of the larval intestinal tract of the goat warble fly Przhevalskiana silenus].
abstract: The goat warble fly from Afghanistan studied in the present paper should be named Przhevalskiana silenus (Brauer) (=Crivellia silenus Brauer) according to recent studies (Wetzel 1972). In the present paper the histology of the gut of all three larval stages is described. Pharynx and oesophagus are well developed in L1. There are no important histological differences to L2 and L3. In contrast to L2 and L3 in L1 the mid gut runs down in a straight line without any looping. There is a cell clot in the first stage which is not present in the second and third one. While in L1 the lumen of the gut is filled with a fine astructural mass there are many blood cells to be found in the gut lumen of L2 beside other nutritive substances. The mid gut in this stage shows a clear histological and functional differentiation in three main sections. The cells of the first and third section secernate, while the second section does not possess secernating cells at all. In L3 there is no secretory activity in the first section of the mid gut at any time, while the cells of all the rest of the mid gut show a merocrine secretion. Neither in L2 nor in L3 any of the two types of cells differing in size in the mid gut's (ED2) epithelium ever secernates. In the mid gut of L1 unspecific esterases have been found. In L2 the same enzymes are produced in the same place. In addition proteins are produced in the salivary glands. They obviously get secernated by the second portion of the salivary glands, which are developed in this stage.
mesh_terms: D000346:Afghanistan; D000818:Animals; D004175:Diptera / Q000033:anatomy & histology* / Q000254:growth & development; D007422:Intestines / Q000033:anatomy & histology*; D007814:Larva / Q000033:anatomy & histology / Q000254:growth & development
vernacular_title: Die Histologie des larvalen Darmtraktes der Ziegendasselfliege Przhevalskiana silenus