scholarly journals Egg shell morphology of an amblyceran louse, Hohorstiella rampurensis (Phthiraptera) infesting ring dove, Streptopelia decaocta

2016 ◽  
Vol 8 (1) ◽  
pp. 469-472
Author(s):  
Padam Singh ◽  
Jagirti Madan ◽  
Nidhi Gupta

Scanning electron microscopy (SEM) study showed that miniature rice grain like egg shell of Hohorstiella rampurensis was covered by obliquely placed opercular disc. The apophyses were present only on one side of the egg shell. There were 25-35 long elongated rod like apophyses (apically turned), which were arranged in 3-4 rows and occurred in pair. The nature of egg shell of H. rampurensis characteristically differed from that of H. lata (the only species of Hohorstiella studied, so far). The study further indicates about the role of egg morphology as a guide to louse taxonomy.

1995 ◽  
Vol 26 (4) ◽  
pp. 425-438 ◽  
Author(s):  
Rudolf Meier

AbstractThe eggs of 21 species in 12 genera of Sepsidae were studied using scanning electron microscopy. All but the eggs of Ortalischema have respiratory filaments which aid in gas exchange. Judged by positional differences and the lack of a central canal, the two filaments of Orygma are not homologous to the single filament of most remaining sepsids. Hinton's hypothesis that egg filaments are plesiomorphic for the Sepsidae is therefore rejected. Three egg characters are added to an existing data set comprising 58 taxa and 85 larval and adult characters. The egg characters allow the unambiguous placement of Lasionemopoda, for which the larval and adult data set had suggested two different positions on equally parsimonious trees. Based on the position of Lasionemopoda, the evolution of the fore femora of the Sepsidae is briefly discussed. The egg morphology of the Sepsidae is also compared to the morphology of drosophiline eggs which also have egg filaments.


Zootaxa ◽  
2007 ◽  
Vol 1465 (1) ◽  
pp. 15-29 ◽  
Author(s):  
NICOLÁS UBERO-PASCAL ◽  
M. ANGELS PUIG

The chorionic patterns of Ephemeroptera eggs are very diverse and these have often been used for taxonomic and systematic purposes. In a great number of species, including Potamanthus luteus, Ephemera danica and Oligoneuriella rhenana, these egg features have been studied using light microscopy. However, current trends in egg morphology studies use scanning electron microscopy (SEM), so that the eggs of these species need to be re-described in order to establish morphological comparisons. The general chorionic features which have already been described in these three species are confirmed in our SEM study, although a more detailed description of both the architecture and arrangement of these can now be offered. In addition, this study has allowed us to note new morphological data, such as the chorionic reticulation in P. luteus and the complex extrachorion-adhesive layer in E. danica; classification of the lateral attachment structure in P. luteus and O. rhenana has been changed; and the variability of the polar cap observed in P. luteus underlines the care that must to be taken when selecting chorionic structures for taxonomic purposes.


Author(s):  
Robert D. Specian ◽  
Venita F. Allison ◽  
J. E. Ubelaker ◽  
J. H. Martin

The structure and composition of parasitic nematode eggs, particularly the shells, are of interest to various investigators. Egg morphology is widely used for species identification where sacrifice of the host is not desirable. Scanning electron microscopy (SEM) allows surface sculpture patterns on eggs of closely related species to be observed and aids in identification. The egg shell, in many species of parasitic nematodes, is composed of a proteinchitin-lipid complex which, unfortunately, is labile in many organic solvents including those routinely employed in the preparation of samples for SEM by the critical point drying method.The present study is concerned with the fine surface morphology of eggs from Toxocara canis (Werner, 1782), Toxocara mystax (Zeder, 1800), and Ascaris suum Goeze, 1782, as revealed by SEM after several preparative procedures.


Author(s):  
Douglas William Jones

Within the past 20 years, archaeobotanical research in the Eastern United States has documented an early agricultural complex before the dominance of the Mesoamerican domesticates (corn, beans, and squash) in late prehistoric and historic agricultural systems. This early agricultural complex consisted of domesticated plants such as Iva annua var.macrocarpa (Sumpweed or Marshelder), Hellanthus annuus (Sunflower) and Chenopodium berlandieri, (Goosefoot or Lasbsquarters), and heavily utilized plants such as Polygonum erectum (Erect Knotweed), Phalaris caroliniana (May grass), and Hordeum pusillum (Little Barley).Recent research involving the use of Scanning Electron Microscopy (SEM) specifically on Chenopodium has established diagnostic traits of wild and domesticated species seeds. This is important because carbonized or uncarbonized seeds are the most commonly recovered Chenopodium material from archaeological sites. The diagnostic seed traits assist archaeobotanists in identification of Chenopodium remains and provide a basis for evaluation of Chenopodium utilization in a culture's subsistence patterns. With the aid of SEM, an analysis of Chenopodium remains from three Late Prehistoric sites in Northwest Iowa (Blood Run [Oneota culture], Brewster [Mill Creek culture], and Chan-Ya-Ta [Mill Creek culture]) has been conducted to: 1) attempt seed identification to a species level, 2) evaluate the traits of the seeds for classification as either wild or domesticated, and 3) evaluate the role of Chenopodium utilization in both the Oneota and Mill Creek cultures.


2007 ◽  
Vol 22 (7) ◽  
pp. 1879-1887 ◽  
Author(s):  
Y.K. Jee ◽  
Y.H. Ko ◽  
Jin Yu

Varying amounts of Zn (1, 3, and 7 wt%) were added to Sn–3.5Ag solder on a Cu pad, and the resultant solder joint microstructures after a reflow and isothermal aging (150 °C, up to 500 h) were investigated using scanning electron microscopy, energy dispersive x-ray, and x-ray diffraction, which were subsequently correlated to the results of microhardness and drop tests. Zinc was effective in improving the drop resistance of Sn–3.5Ag solder on the Cu pad, and an addition of 3 wt% Zn nearly doubled the number of drops-to-failure (Nf). The beneficial role of Zn was ascribed to suppression of Cu6Sn5 and precipitation of Zn-containing intermetallic compounds (IMCs). However, the Zn effect was reduced as Cu6Sn5 and Ag3Sn precipitated in a joint IMC layer after prolonged aging. The interface between Ag5Zn8 and Cu5Zn8 was resistant to drop impact, but two other layered IMC structures of Cu6Sn5/Cu3Sn and Cu5Zn8/Cu6Sn5 were not.


2019 ◽  
Vol 57 (3) ◽  
pp. 745-754
Author(s):  
Francisco Augusto da Silva Ferreira ◽  
Rejane de Castro Simões ◽  
Ruth Leila Ferreira-Keppler ◽  
Jeronimo Alencar ◽  
Vera Margarete Scarpassa ◽  
...  

Abstract The eggs of three Amazonian species of the genus Mansonia (Diptera: Culicidae) were analyzed using morphological and morphometric characters. Eggs of Mansonia humeralis Dyar & Knab, 1916 were morphologically different from those of Mansonia titillans (Walker, 1848) and Mansonia amazonensis (Theobald, 1901), which were more similar to each other according to linear and geometric morphometry. A principal component analysis generated from elliptic Fourier contour data (PC1—92.6% and PC2—2.61%) indicated that Ma. amazonensis and Ma. titillans are more similar to each other than either is to Ma. humeralis. Discriminant multivariate analysis was highly accurate with only four classification errors and a 90% accuracy rate. The results indicate that the three Amazonian species can be precisely distinguished in the egg stage and that geometric morphometry based on elliptic Fourier contours is a promising method for distinguishing eggs of species of Mansonia. An identification key based on egg morphology is provided to distinguish the four Neotropical species.


Sign in / Sign up

Export Citation Format

Share Document