scholarly journals The Avocado Sunblotch Viroid: An Invisible Foe of Avocado

Viruses ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 491
Author(s):  
José Ramón Saucedo Carabez ◽  
Daniel Téliz Ortiz ◽  
Moisés Roberto Vallejo Pérez ◽  
Hugo Beltrán Peña

This review collects information about the history of avocado and the economically important disease, avocado sunblotch, caused by the avocado sunblotch viroid (ASBVd). Sunblotch symptoms are variable, but the most common in fruits are irregular sunken areas of white, yellow, or reddish color. On severely affected fruits, the sunken areas may become necrotic. ASBVd (type species Avocado sunblotch viroid, family Avsunviroidae) replicates and accumulates in the chloroplast, and it is the smallest plant pathogen. This pathogen is a circular single-stranded RNA of 246–251 nucleotides. ASBVd has a restricted host range and only few plant species of the family Lauraceae have been confirmed experimentally as additional hosts. The most reliable method to detect ASBVd in the field is to identify symptomatic fruits, complemented in the laboratory with reliable and sensitive molecular techniques to identify infected but asymptomatic trees. This pathogen is widely distributed in most avocado-producing areas and causes significant reductions in yield and fruit quality. Infected asymptomatic trees play an important role in the epidemiology of this disease, and avocado nurseries need to be certified to ensure they provide pathogen-free avocado material. Although there is no cure for infected trees, sanitation practices may have a significant impact on avoiding the spread of this pathogen.

Zootaxa ◽  
2009 ◽  
Vol 2243 (1) ◽  
pp. 1-39 ◽  
Author(s):  
EVERT E. LINDQUIST ◽  
MARÍA L. MORAZA

The genus Anystipalpus Berlese, 1911, of uncertain prior placement in the superfamilies Ascoidea or Dermanyssoidea, is redescribed, based on reexamination of type and other material of the type-species, A. percicola Berlese, and of material representing Anystipalpus livshitsi (Eidelberg) new combination and two new species, A. labiduricola n. sp. and A. kazemii n. sp. Anystipalpus nataliae (Eidelberg) new combination and Anystipalpus ukrainicus (Sklyar) new combination are determined to be junior synonyms of A. percicola Berlese and A. livshitsi (Eidelberg), respectively, new synonymies. The genus is known thus far only from adult females phoretic under the elytra of carabid beetles and the tegmina of labidurid earwigs in Eurasia. The relationships between it and the closely related Antennoseius Berlese, 1916 and Vitzthumia Thor, 1930, are reviewed, and the options for the family level placement of these genera are reconsidered. Attention is given to some gnathosomatic attributes that are commonly overlooked in description of species of these closely related genera. Phoresy and the role of adult female morphs in the life history of these mites, as well as the extraordinary phoretic association of one species with earwigs are discussed.


Paleobiology ◽  
1992 ◽  
Vol 18 (1) ◽  
pp. 50-79 ◽  
Author(s):  
Benjamin J. Greenstein

The class Echinoidea apparently originated during the Ordovician Period and diversified slowly through the Paleozoic Era. The clade then mushroomed in diversity beginning in Late Triassic time and continued expanding into the present. Although this evolutionary history is generally accepted, the taphonomic overprint affecting it has not been explored. To gain a more accurate perception of the evolutionary history of the group, I have compared the diversity history of the family Cidaridae (Echinodermata: Echinoidea) with the preservational style of fossil type species using literature-derived data. The Cidaridae apparently originated in Middle Triassic time and diversified slowly through the Neocomian (Early Cretaceous). Diversity was maintained through the remainder of the Cretaceous and Tertiary Periods, reflecting the diversity history of the subclass. Characterization of the preservational style of type fossil material for the family revealed the following breakdown of preservational states: 60% of species were described on the basis of disarticulated skeletal material, primarily spines; 20% based on intact coronas denuded of spines, apical system, Aristotle's lantern and peristomial plates; 10% based on large coronal fragments; and 10% based on other skeletal elements. This distribution may represent the effect of a disarticulation threshold on the condition of echinoid carcasses before final burial and suggests that preservation of intact specimens may be very unlikely. For cidaroids, previous work has suggested that this threshold is likely to be reached after 7 days of decay.Comparison of the diversity history of the Cidaridae with the preservation data reveals that characteristic patterns of taphonomic overprint have affected the group since its origination in Middle Triassic time, and the nature of that overprint has changed over time: the early diversity history of the group is characterized by occurrences of fragmented fossil material, with spines predominant; further radiation of the group in mid-Jurassic time coincided with an increase in modes of preservation, ranging between exceptionally well-preserved material and disarticulated skeletal elements. Finally, type material is more rarely described from younger stratigraphic intervals (Miocene–Pleistocene) and consists predominantly of disarticulated skeletal elements and coronal fragments larger than an interambulacrum in size. Intact, denuded coronas are noticeably lacking.The number of type species of Cidaridae described in each stratigraphic interval has not been consistent during post-Paleozoic time. Middle Triassic, Malm (Upper Jurassic), Senonian (Upper Cretaceous) and Eocene series yielded significantly (α = .05) higher numbers of type specimens per million years, while the Lias (Lower Jurassic), Dogger (Mid-Jurassic), Lower Cretaceous and Paleocene yielded significantly (α = .05) lower numbers of type specimens per million years. This may be the result of a combination of taxonomic, sampling, and geographical biases.


Zootaxa ◽  
2009 ◽  
Vol 2107 (1) ◽  
pp. 65-68
Author(s):  
GERD WEIGMANN ◽  
ROY A. NORTON

In the literature there is much confusion about the identity and taxonomic position of two common oribatid mite species in the family Ceratozetidae: Oribates setosus C.L. Koch, 1839, and Murcia trimaculata C.L. Koch, 1835. Related to these problems, there are contrary opinions about the validity of two ceratozetid genera, Murcia Koch, 1835 and Trichoribates Berlese, 1910, and the identity of their type species. Important conclusions on these issues have been proposed in the past (Jacot 1929; Pérez-Iñigo 1993) but these were not followed in an important recent catalog (Subías 2004). In the following, we summarize and comment on the history of these problems, and argue in the context of the current ICZN rules to preserve nomenclatural stability.


Insects ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 394 ◽  
Author(s):  
Robin Kundrata ◽  
Gabriela Packova ◽  
Johana Hoffmannova

Insect fossils bear important information about the evolutionary history of the group. The fossil record of Elateridae, a large cosmopolitan beetle family, has been greatly understudied and the available data are often replete with ambiguity and uncertainty. The research of Elateridae evolution cannot be done without solid genus-group name concepts. In this study we provide an updated comprehensive summary of the fossil genera in Elateridae, including their systematic placement and information on the type species, gender, number of species, age range, and relevant bibliography. We list seven valid fossil genera in Agrypninae, one in Cardiophorinae, two in Dendrometrinae, five in Elaterinae, two in Negastriinae, one in Omalisinae, one in Pityobiinae, and 36 in Protagrypninae. Additional 19 genera are tentatively classified as Elateridae incertae sedis, and their placements are discussed. Further, we move genera Babuskaya Martins-Neto & Gallego, 2009, Cardiosyne Martins-Neto & Gallego, 2006, Fengningia Hong, 1984 and Gemelina Martins-Neto & Gallego, 2006 from Elateridae to Coleoptera incertae sedis. We also discuss the genera previously placed in Elateridae, which are currently not included in the family. The data on the fossil generic diversity suggest that Elateridae originated in the Triassic and rapidly diversified and became comparatively abundant through the Jurassic. We call for further research on the fossil Elateridae from various deposits in order to increase our knowledge on the origin, evolution, and palaeodiversity of the group.


Zootaxa ◽  
2020 ◽  
Vol 4890 (1) ◽  
pp. 148-150
Author(s):  
N.V. AYISHA MAWADDA ◽  
P. GIRISH KUMAR ◽  
P.M. SURESHAN

The digger wasp genus Kohliella Brauns, 1910, a member of the tribe Larrini, subfamily Crabroninae of the family Crabronidae, is a rarely occurring genus comprising only three known species worldwide (Pulawski 1991; 2020). The genus has been recorded from the Ethiopian (South Africa and Zimbabwe; two species) and Oriental (Sri Lanka; one species) regions. Brauns (1910) erected the genus based on the type species Kohliella alaris from South Africa. The genus is characterized by a V-shaped swelling on the frons, an oblong tubercle on the mandible and a petiolate third submarginal cell of the forewing (Bohart & Menke 1976; Pulawski 1991). The nesting habits are known only for Kohliella alaris. Gess and Gess (1980) studied the life history of this species. It preys on nymphal tree cricket Oecanthus filiger Walker, and nests in the ground in flat, sandy areas with sparse vegetation; nests are constructed prior to hunting. In this paper, Kohliella anula Pulawski, 1991, previously known from Sri Lanka only, is recorded for the first time from India. 


Zootaxa ◽  
2011 ◽  
Vol 2802 (1) ◽  
pp. 1 ◽  
Author(s):  
D. J. WILLIAMS ◽  
P. J. GULLAN ◽  
D. R. MILLER ◽  
D. MATILE-FERRERO5 ◽  
SARAH I. HAN

For almost a century, the scale insect genus Puto Signoret (Hemiptera: Sternorrhyncha: Coccoidea) was considered to belong to the family Pseudococcidae (the mealybugs), but recent consensus accords Puto its own family, the Putoidae. This paper reviews the taxonomic history of Puto and family Putoidae, compares the morphology of Puto to that of Ceroputo Šulc and Phenacoccus Cockerell, and reassesses the status of all species that have been placed in Puto to determine whether they belong to the Putoidae or to the Pseudococcidae. For 49 of 57 species that have been placed in Puto, as listed in the online database ScaleNet, we score and tabulate features that are diagnostic for Putoidae and then list all species in their correct family placement. For comparison, we include a few species of Pseudococcidae, namely five species of Phenacoccus, including the type species Phenacoccus aceris (Signoret), and the type species of Ceroputo, C. pilosellae Šulc. We provide revised synonymy lists for Puto and Ceroputo, a brief diagnosis of each genus, synonymy lists and notes for several species for which we suggest recombinations or additional synonyms, or for which we have additional data on morphology. We provide a brief diagnosis of Phenacoccus for comparison with Ceroputo and Puto. As a result of our study, we recognise 47 extant and two fossil species of Puto, and six species of Ceroputo. The New World species Puto mimicus McKenzie and Puto nulliporus McKenzie are transferred to the mealybug genus Ceroputo as Ceroputo mimicus (McKenzie) comb. nov. and Ceroputo nulliporus (McKenzie) comb. nov., respectively, and the Old World species Puto pini Danzig and Puto vaccinii Danzig are recognised as Ceroputo pini (Danzig) comb. rev. and Ceroputo vaccinii (Danzig) comb. rev., respectively, in agreement with Tang (1992). The Old World species Puto graminis Danzig is transferred to Ceroputo as Ceroputo graminis (Danzig) comb. nov. Based only on a study of the literature, the following two names are treated here as junior subjective synonyms of Ceroputo pilosellae: Phenacoccus asteri Takahashi syn. nov. and Puto jarudensis Tang syn. nov. We agree with Tang (1992) that Leococcus erigeroneus Kanda should be treated as a junior subjective synonym of C. pilosellae and thus the genus name Leococcus Kanda, erected for L. erigeroneus and formerly treated as a junior synonym of Puto, is a junior synonym of Ceroputo.


2021 ◽  
Vol 45 ◽  
pp. e73217
Author(s):  
Isaac Garrido Benavent

The present work represents the first comprehensive phylogenetic study of the dothideomycete genus Seynesiella. The genus belongs into the family Cylindrosympodiaceae within the order Venturiales, based on a phylogeny reconstructed with five loci. The high genetic diversity found within the type species, S. juniperi, points towards cryptic speciation, with up to five distinct species that might be associated to different Juniperus hosts. Combining phylogenetics and multi-locus delimitation analyses, together with more detailed measurements of ascospores, will be fundamental for a better understanding of species boundaries and the biogeographic history of the delimited species, as well as for revealing more specific fungal-plant association patterns.


Author(s):  
Joachim Langeneck ◽  
Michele Barbieri ◽  
Ferruccio Maltagliati ◽  
Alberto Castelli

Cirrophorus nikebianchii sp. nov. is described from brackish-water and organically enriched marine environments of the Mediterranean Sea. The new species is characterized by a very small prostomial antenna and a high number of branchiae pairs. A phylogenetic analysis carried out through the use of three molecular markers (16S rRNA, 18S rRNA and COI) supports the distinction between C. nikebianchii and C. furcatus, a closely related species with which it has been misidentified. Preliminary results obtained show that the genera Cirrophorus and Paradoneis are not reciprocally monophyletic, with uncertain relationships with the remaining genera of Paraonidae. This outcome suggests that the evolutionary history of Paraonidae is less straightforward than previously supposed. Moreover, the uncertainty about the taxonomic status of Paraonides neapolitana, type species of the genus Paraonides, makes the revamping of the taxonomy of Paraonidae more challenging. Awaiting support from studies including more species, and based on morphological and genetic data as well, we suggest to provisionally maintain the current use of Cirrophorus and Paradoneis, and to assign to Paraonella the species traditionally assigned to Paraonides.


2016 ◽  
Vol 54 (7) ◽  
pp. 1694-1699 ◽  
Author(s):  
John P. Dekker ◽  
Anna F. Lau

TheStreptococcus bovisgroup has undergone significant taxonomic changes over the past 2 decades with the advent of new identification methods with higher discriminatory power. Although the current classification system is not yet embraced by all researchers in the field and debate remains over the performance of molecular techniques for identification to the species level within the group, important disease associations for several members of the group have been clarified. Here, we provide a brief overview of the history of theS. bovisgroup, an outline of the currently accepted classification scheme, a review of associated clinical syndromes, and a summary of the performance and diagnostic accuracy of currently available identification methods.


2010 ◽  
Vol 24 (2) ◽  
pp. 194 ◽  
Author(s):  
Leonardo G. Pileggi ◽  
Fernando L. Mantelatto

The genus Macrobrachium Bate, 1868 is one of the best examples of widespread crustacean genera distributed globally throughout tropical and subtropical waters. Previous investigators have noted the systematic complexity of the group, and have suggested rearrangements within the family Palaemonidae. Our phylogenetic analysis of new mitochondrial DNA sequences of 58 species of Macrobrachium distributed mainly in America support the hypothesis of monophyly of this genus, if Cryphiops Dana, 1852 is accepted as a generic synonym. We concluded that the independent evolution of different types of life cycle (abbreviated larval development – ALD and extended larval development – ELD) must have occurred more than once in the history of the group. Similarly, we also concluded that the current type species of the genus, Macrobrachium americanum Bate, 1868, should not be considered valid, as previously proposed. The synonymy of two members of the ‘olfersi’ species complex (M. birai Lobão, Melo & Fernandes, 1986 and M. holthuisi Genofre & Lobão, 1978) with M. olfersi (Wiegmann, 1836) was confirmed. Similar results were found in comparing M. petronioi Melo, Lobão & Fernandes, 1986 and M. potiuna (Müller, 1880), in which the genetic divergence placed M. petronioi within the level of intraspecific variation of M. potiuna. The taxonomic status of the genus Cryphiops, as well as theories on the origin of Macrobrachium, is also called into question.


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