The Whiteflies in Egypt (Hemiptera: Aleyrodidae)

2021 ◽  
Vol 55 (2) ◽  
pp. 193-205
Author(s):  
S. Abd-Rabou ◽  
G. A. Evans

Whiteflies are the most important pests of economic crops in Egypt causing huge damage to them by their direct feeding, formation of sooty mold on plants and vectoring of plant viruses. An updated list of the 25 species of whiteflies (Hemiptera: Aleyrodidae) known to occur in Egypt and an identification key are provided.

Author(s):  
N.C. Lyon ◽  
W. C. Mueller

Schumacher and Halbsguth first demonstrated ectodesmata as pores or channels in the epidermal cell walls in haustoria of Cuscuta odorata L. by light microscopy in tissues fixed in a sublimate fixative (30% ethyl alcohol, 30 ml:glacial acetic acid, 10 ml: 65% nitric acid, 1 ml: 40% formaldehyde, 5 ml: oxalic acid, 2 g: mecuric chloride to saturation 2-3 g). Other workers have published electron micrographs of structures transversing the outer epidermal cell in thin sections of plant leaves that have been interpreted as ectodesmata. Such structures are evident following treatment with Hg++ or Ag+ salts and are only rarely observed by electron microscopy. If ectodesmata exist without such treatment, and are not artefacts, they would afford natural pathways of entry for applied foliar solutions and plant viruses.


Author(s):  
K. Pegg-Feige ◽  
F. W. Doane

Immunoelectron microscopy (IEM) applied to rapid virus diagnosis offers a more sensitive detection method than direct electron microscopy (DEM), and can also be used to serotype viruses. One of several IEM techniques is that introduced by Derrick in 1972, in which antiviral antibody is attached to the support film of an EM specimen grid. Originally developed for plant viruses, it has recently been applied to several animal viruses, especially rotaviruses. We have investigated the use of this solid phase IEM technique (SPIEM) in detecting and identifying enteroviruses (in the form of crude cell culture isolates), and have compared it with a modified “SPIEM-SPA” method in which grids are coated with protein A from Staphylococcus aureus prior to exposure to antiserum.


Author(s):  
M. F. Miller ◽  
A. R. Rubenstein

Studies of rotavirus particles in humans, monkeys and various non-primates with acute gastroenteritis have involved detection of virus in fecal material by electron microscopy. The EM techniques most commonly employed have been the conventional negative staining (Fig. 1) and immune aggregation (Fig. 2) procedures. Both methods are somewhat insensitive and can most reliably be applied to samples containing large quantities of virus either naturaLly or as a result of concentration by ultracentrifugation. The formation of immune complexes by specific antibody in the immune aggregation procedures confirms the rotavirus diagnosis, but the number of particles per given microscope field is effectively reduced by the aggregation process. In the present communication, we describe use of an on-grid immunoelectron microscopic technique in which rotavirus particles are mounted onto microscope grids that were pre-coated with specific antibody. The technique is a modification of a method originalLy introduced by Derrick (1) for studies of plant viruses.


2019 ◽  
Vol 18 (2) ◽  
pp. 127
Author(s):  
Purnama Hidayat ◽  
Denny Bintoro ◽  
Lia Nurulalia ◽  
Muhammad Basri

Species identification, host range, and identification key of whiteflies of Bogor and surrounding area. Whitefly (Hemiptera: Aleyrodidae) is a group of insects that are small, white, soft-bodied, and easily found on various agricultural crops. Whitefly is a phytophagous insect; some species are important pests in agricultural crops that can cause direct damage and can become vectors of viral diseases. The last few years the damage caused by whitefly in Indonesia has increased. Unfortunately, information about their species and host plants in Indonesia, including in Bogor, is still limited. Kalshoven, in his book entitled Pest of Crops in Indonesia, published in the 1980s reported that there were 9 species of whitefly in Indonesia. The information on the book should be reconfirmed. Therefore, this study was conducted to determine whitefly species and its host plants in Bogor and its surroundings. Whiteflies is identified based on the ‘puparia’ (the last instar of the nymph) collected from various agricultural plants, ornamental plants, weeds, and forest plants. A total of 35 species of whiteflies were collected from 74 species and 29 families of plants. The collwcted whiteflies consist of four species belong to Subfamily Aleurodicinae and 31 species of Subfamily Aleyrodinae. The most often found whitefly species were Aleurodicus dispersus, A. dugesii, and Bemisia tabaci. A dichotomous identification key of whiteflies was completed based on morphological character of 35 collected species. The number of whitefly species in Bogor and surrounding areas were far exceeded the number of species reported previously by Kalshoven from all regions in Indonesia.


2013 ◽  
Vol 38 ◽  
pp. 229-231
Author(s):  
María Talavera Solís ◽  
Carlos Sánchez Casimiro-Soriguer ◽  
Salvador Talavera Lozano

Crepis sect. Lepidoseris sensu Babcock in the Iberian Peninsula and Balearic Islands. Palabras clave. Clave de identificación, nomenclatura, tipificación, distribución, Crepis bermejana sp. nov., combinaciones nuevas. Key words. Identification key, nomenclature, chorology, typification, Crepis bermejana sp. nov., new combinations.


2013 ◽  
Vol 38 ◽  
pp. 231-240 ◽  
Author(s):  
María Talavera Solís ◽  
Carlos Sánchez Casimiro-Soriguer ◽  
Salvador Talavera Lozano

Crepis sect. Lepidoseris sensu Babcock in the Iberian Peninsula and Balearic Islands. Palabras clave. Clave de identificación, nomenclatura, tipificación, distribución, Crepis bermejana sp. nov., combinaciones nuevas. Key words. Identification key, nomenclature, chorology, typification, Crepis bermejana sp. nov., new combinations.


Author(s):  
M. S. Knyazev

A taxonomic review of species and intraspecific taxa of the Astragalus L. section Helmia Bunge is presented. We treat the section Helmia in a traditional, narrow scope, including only 9 species and subspecies: A. helmii Fisch. ex DC., A. tergeminus (Knjaz., Kulikov et E. G. Philippov) Knjaz., A. permiensis C. A. Mey. ex Rupr., A. depauperatus Ledeb. (= A. chakassiensis Polozhij), A. kasachstanicus Golosk. subsp. kasachstanicus, A. kasachstanicus subsp. coloratus Knjaz., A. gregorii B. Fedtsch. et Basil. (= A. tuvinicus Timokhina), A. heptapotamicus Sumnev., A. ionae Palib. ex Gontsch. et Popov. With regard to the other 16 species of sect. Helmia in its widest sense, as accepted in the monograph by D. Podlech and Sh. Zarre (2013), we believe it more correct to attribute them to other sections. The rank of A. helmii var. tergeminus Knjaz., Kulikov et E. G. Philippov is raised to the species, A. tergeminus (Knjaz., Kulikov et E. G. Philippov) Knjaz. It is shown that A. gregorii is a priority name of A. tuvinicus. The epitype of A. permiensis C. A. Mey. ex Rupr. is designated. An identification key and a map of distribution for all species and subspecies of Astragalus sect. Helmia are presented.


2015 ◽  
Vol 49 ◽  
pp. 282-288 ◽  
Author(s):  
I. N. Urbanavichene

Until recently only two species of Gyalideopsis (G. piceicola and G. alnicola) were known from very few localities in Russia. Gyalideopsis helvetica is reported for the first time for Russia from the southern part of Baikal area (KhamarDaban Range, Baikalsky Zapovednik). Description of the collected specimen and its comparison with the literature data are provided; morphology, ecology and distribution of G. helvetica are discussed. The hyphophores of G. helvetica are recorded and described for the first time. An identification key to Gyalideopsis species known in Russia is provided.


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