Electron Microscopic studies on the antennal sensilla and the pheromone-producing glands of two important oil seed pests

Author(s):  
Kaiser Jamil ◽  
K.N. Jyothi ◽  
A.L. Prasuna

Sensory mechanisms underlying insect chemical communication have been given considerable attention in recent years. A study on the ultrastructural details of the antennal appendages and the pheromone producing structures of Achoea janata L. and Ophiusa algira were studied with scanning electron microscope in order to understand the mechanisms of olfactory perception and pheromone release.For fixation of pheromone producing glands of A.Janata and O.Algira the posterior region of the abdomen was pressed sufficiently and flooded with carnoys fluid for complete excedation of the 9th abdominal along with the ovipositor. The above specimens as well as the antennal appendages were then fixed in 4% glutaraldehyde in phosphate buffer of 7.2 pH dehydrated in increasing grades of ethylalcohol and critical point dried. The specimens were then coated with gold in vacuum evaporator and observed in a Hitachi S-520 evaporator and observed in a Hitachi S-520 SEM operated at 20KV.

Author(s):  
Chelladurai Stella ◽  
Packiam Paul ◽  
Chelladurai Ragunathan

Scanning electron microscopic studies (SEM) revealed that the radula of Muricanthus kuesterianus resembled that of Muricanthus virgineus in most details. But there were some apparent differences. In Muricanthus kuesterianus rachidian tooth have a broad base than that of Muricanthus virgineus. The base of the median cusp was broad, short, stout and pointed straight towards the anterior end. The left  lateral cusp elongated,  sharp, slightly bent and pointed outwards and the right lateral cusp dorso ventrally flattened and the anterior end small, slightly pointed. In between the median and left lateral cusps, a sharp and pointed denticle is present where as the right laterals and median cups there is no denticle. The lateral teeth which are two in numbers flanked median rachidian.Keywords: Scanning Electron Microscope, Radula, Gastropoda, Muricidae, Muricanthus kuesteianus,


Author(s):  
M.D. Graham

The recent development of the scanning electron microscope has added great impetus to the study of ultrastructural details of normal human ossicles. A thorough description of the ultrastructure of the human ossicles is required in order to determine changes associated with disease processes following medical or surgical treatment.Human stapes crura were obtained at the time of surgery for clinical otosclerosis and from human cadaver material. The specimens to be examined by the scanning electron microscope were fixed immediately in the operating room in a cold phosphate buffered 2% gluteraldehyde solution, washed with Ringers, post fixed in cold 1% osmic acid and dehydrated in graded alcohol. Specimens were transferred from alcohol to a series of increasing concentrations of ethyl alcohol and amyl acetate. The tissue was then critical point dried, secured to aluminum stubs and coated with gold, approximately 150A thick on a rotating stage in a vacuum evaporator. The specimens were then studied with the Kent-Cambridge S4-10 Scanning Electron Microscope at an accelerating voltage of 20KV.


1982 ◽  
Vol 53 (2) ◽  
pp. 510-515 ◽  
Author(s):  
W. G. Guntheroth ◽  
D. L. Luchtel ◽  
I. Kawabori

We examined latex casts of the pulmonary microcirculation with the scanning electron microscope (SEM). Mature rats were anesthetized and ventilated; the pulmonary vasculature was washed out with lactated Ringer solution and then filled with a mixture of Geon latexes. The airways were filled with glutaraldehyde with resulting transmural vascular pressures of 10 cmH2O. After critical-point drying and corrosive removal of the lung tissue, SEM studies of the vascular replicas revealed two distinct patterns of pulmonary microcirculation: 1) sparse, long, tubular capillaries that comprise the thin subpleural layer and appear as “filler” in the peribronchial spaces; and 2) alveolar microcirculation that is composed of tightly matted, intersecting tubules, shorter but of the same diameter as type 1, in spherical array in two layers. The alveolar capillaries at low magnification appear superficially as sheets; however, the detailed morphology is not consistent with the sheet-and-post model. We conclude that the basic component of the pulmonary microcirculation is tubular and not different from other capillary beds except in density.


Author(s):  
E. O. Fadeeva

Conducted electron microscopic investigation of the primary remex fine structure of thirteen species of Owls (Strigiformes), using a scanning electron microscope (SEM). It is shown that Owls (Strigiformes) have a number of specific primary remex microstructural characteristics. First of all, these are the features of the structure of the pennaceous barb: a cross section configuration, a pith architectonics on the cross section and longitudinal sections, a cuticular structur of the barb. A number of the unique features in the microstructure of the vanules of the pennaceous barb have been found for the first time (at the scanning electron microscope level, at a large SEM magnification). First of all, these are the structural features of the distal barbules and the structure of the apical portion of the barb with the elongated proximal barbules and the distal barbules tightly contiguous to the ramus and closed with each other. Mentioned characteristics make for the thick velvet-like dorsal surface of the vane and the presence of a complex of peculiar “bunches” (fringes) forming the cleft edge (a fringed edge) of the inner vane – exceptionally specific adaptive characteristics in Strigiformes. Рresentenced original research results suggest that Owls (Strigiformes) have a number specific microstructural characteristics of the primary remex and also a number of the unique features in the microstructure of the primary remex which reflecting the ecological and morphological adaptations conditioned by the flight specificity.


Zootaxa ◽  
2007 ◽  
Vol 1544 (1) ◽  
pp. 59-68 ◽  
Author(s):  
NA LI ◽  
BING-ZHONG REN ◽  
MIAO LIU

The types, numbers and distributions of antennal sensilla were studied in both male and female adults of eight Acrididae species in Northeast China using scanning electron microscope (SEM). Totally, there were thirteen types of sensilla found on the antennae. They were identified as trichoid sensilla (I, II), chaetic sensilla (I, II), basiconic sensilla (I, II, III, IV, V), cavity sensilla, coeloconic sensilla, boehm's bristles and paddle-shaped sensilla. The types of antennal sensilla in each Acrididae species ranged from nine to twelve. Each of the species had the same types of antennal sensilla in male and female, and males had more abundant basiconic sensilla, chaetic sensilla, coeloconic sensilla, cavity sensilla than females. Acrida cinerca had the largest total numbers of sensilla, and Euthystria lueifemora had the fewest. Boehm's bristles had a concentration in the base of the pedicel. Paddle-shaped sensilla had a concentration in the base of the scape. There were significant differences in the distribution of the other eleven types of sensilla.


2016 ◽  
Vol 90 (4) ◽  
pp. 741-762 ◽  
Author(s):  
Brian L. Hoffman ◽  
Scott A. Hageman ◽  
Gregory D. Claycomb

AbstractAlthough Ptychodus teeth are well known in Late Cretaceous marine deposits in North America and Europe and a few specimens with jaw elements have been discovered, the taxonomic position of the shark genus Ptychodus is enigmatic due to the lack of preservation of diagnostic material other than teeth. These sharks possessed a pavement dentition suited to a diet of hard-shelled macroinvertebrates (durophagy), leading several studies to variously describe Ptychodus as a batoid, a hybodont shark, or a selachimorph. Members of the Selachimorpha share one dental synapomorphy, a triple-layered enameloid (TLE) consisting of an outer shiny-layered enameloid (SLE) of randomly oriented hydroxyapatite crystallites, a middle layer of parallel-bundled enameloid (PBE), and an inner layer of tangled-bundled enameloid (TBE). Batoids and hybodonts both have teeth with single crystallite enameloid (SCE). We examined teeth from Ptychodus collected from the Lincoln Limestone of the Greenhorn Formation of Barton County, Kansas, and compared their enameloid ultrastructure with that of a Carboniferous hybodontiform and the Cretaceous lamniform shark Squalicorax curvatus Williston, 1900. Scanning electron microscopic examination of Ptychodus shows that crystallite bundling in the form of a TLE is evident in these teeth. The PBE is most apparent at transverse enameloid ridges of Ptychodus teeth. Columns of dentine penetrate into the tooth enameloid, and the crystallites near the dentine are randomly oriented. These observations bolster the argument that Ptychodus is a genus of highly specialized selachimorph shark, rather than a hybodont or batoid.


1997 ◽  
Vol 3 (S2) ◽  
pp. 113-114
Author(s):  
C. Baker ◽  
E.D. Green

The large eggs of Haematopinus phacochoeri are found attached to the long dorsal mane bristles of the diurnal warthog. The eggs are generally exposed to great environmental stresses such as excessive sunlight and temperature as well as the occasional plunge under water or mud during grooming. This investigation was therefore undertaken to determine how the eggs of H. phococoeri are adapted to tolerate the various environmental changes it is constantly exposed to. To our knowledge no other SEM study on the eggs of this species has been performed.Specimens still attached to the bristles were fixed in 70% ethanol, dehydrated and ultrasonically cleaned. Some eggs were longitudinally sectioned with a razor blade to expose the chorionic layers. The eggs were critical point dried in liquid CO2, mounted and viewed by means of a Leica Stereoscan 420 scanning electron microscope.The general structure of the shell consists of two layers of chorion, i.e. the endo-and exochorion. These two layers are attached at the pre-formed line of weakness at the operculum and again near the hydropyle. Elsewhere these two layers are completely separated by the respiratory layer.


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