scholarly journals Morphometric and molecular discrimination of the sugarcane aphid, Melanaphis sacchari, (Zehntner, 1897) and the sorghum aphid Melanaphis sorghi (Theobald, 1904)

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0241881
Author(s):  
Samuel Nibouche ◽  
Laurent Costet ◽  
Raul F. Medina ◽  
Jocelyn R. Holt ◽  
Joëlle Sadeyen ◽  
...  
Keyword(s):  
Hind Tibia ◽  
Molecular Data ◽  
Distribution Area ◽  
Molecular Evidence ◽  
Melanaphis Sacchari ◽  
Sugarcane Aphid ◽  
The Us ◽  
Species Separation ◽  
The Caribbean ◽  
Morphological Species

Melanaphis sacchari(Zehntner, 1897) andMelanaphis sorghi(Theobald, 1904) are major worldwide crop pests causing direct feeding damage on sorghum and transmitting viruses to sugarcane. It is common in the scientific literature to consider these two species as synonyms, referred to as the ‘sugarcane aphid’, although no formal study has validated this synonymy. In this study, based on the comparison of samples collected from their whole distribution area, we use both morphometric and molecular data to better characterize the discrimination betweenM.sacchariandM.sorghi. An unsupervised multivariate analysis of morphometric data clearly confirmed the separation of the two species. The best discriminating characters separating these species were length of the antenna processus terminalis relative to length of hind tibia, siphunculus or cauda. However, those criteria sometimes do not allow an unambiguous identification. Bayesian clustering based on microsatellite data delimited two clusters, which corresponded to the morphological species separation. The DNA sequencing of three nuclear and three mitochondrial regions revealed slight divergence between species. In particular, the COI barcode region proved to be uninformative for species separation because one haplotype is shared by both species. In contrast, one SNP located on the nuclear EF1-α gene was diagnostic for species separation. Based on morphological and molecular evidence, the invasive genotype damaging to sorghum in the US, Mexico and the Caribbean since 2013 is found to beM.sorghi.

scholarly journals Morphometric and Molecular Discrimination of the sugarcane aphid, Melanaphis sacchari, (Zehntner, 1897) and the sorghum aphid Melanaphis sorghi (Theobald, 1904)

2020 ◽  
Author(s):  
Samuel Nibouche ◽  
Laurent Costet ◽  
Raul F. Medina ◽  
Jocelyn R. Holt ◽  
Joëlle Sadeyen ◽  
...  
Keyword(s):  
Hind Tibia ◽  
Molecular Data ◽  
Distribution Area ◽  
Molecular Evidence ◽  
Melanaphis Sacchari ◽  
Sugarcane Aphid ◽  
The Us ◽  
Species Separation ◽  
The Caribbean ◽  
Morphological Species

AbstractMelanaphis sacchari (Zehntner, 1897) and Melanaphis sorghi (Theobald, 1904) are major worldwide crop pests causing direct feeding damage on sorghum and transmitting viruses to sugarcane. It is common in the scientific literature to consider these two species as synonyms, referred to as the ‘sugarcane aphid’, although no formal study has validated this synonymy. In this study, based on the comparison of samples collected from their whole distribution area, we use both morphometric and molecular data to better characterize the discrimination between M. sacchari and M. sorghi. An unsupervised multivariate analysis of morphometric data clearly confirmed the separation of the two species. The best discriminating characters separating these species were length of the antenna processus terminalis relative to length of hind tibia, siphunculus or cauda. However, those criteria sometimes do not allow an unambiguous identification. Bayesian clustering based on microsatellite data delimited two clusters, which corresponded to the morphological species separation. The DNA sequencing of three nuclear and three mitochondrial regions revealed slight divergence between species. In particular, the COI barcode region proved to be uninformative for species separation because one haplotype is shared by both species. In contrast, one SNP located on the nuclear EF1-α gene was diagnostic for species separation. Based on morphological and molecular evidence, the invasive genotype damaging to sorghum in the US, Mexico and the Caribbean since 2013 is found to be M. sorghi.

scholarly journals Comparative Transcriptome Analysis Reveals Genetic Mechanisms of Sugarcane Aphid Resistance in Grain Sorghum

2021 ◽  
Vol 22 (13) ◽  
pp. 7129
Author(s):  
Desalegn D. Serba ◽  
Xiaoxi Meng ◽  
James Schnable ◽  
Elfadil Bashir ◽  
J. P. Michaud ◽  
...  
Keyword(s):  
Differential Expression ◽  
Molecular Mechanisms ◽  
Grain Sorghum ◽  
Lipid Binding ◽  
Multiple Time ◽  
Melanaphis Sacchari ◽  
Resistant Genotype ◽  
Sugarcane Aphid ◽  
Genetic Mechanisms ◽  
Moderately Resistant

The sugarcane aphid, Melanaphis sacchari (Zehntner) (Hemiptera: Aphididae) (SCA), has become a major pest of grain sorghum since its appearance in the USA. Several grain sorghum parental lines are moderately resistant to the SCA. However, the molecular and genetic mechanisms underlying this resistance are poorly understood, which has constrained breeding for improved resistance. RNA-Seq was used to conduct transcriptomics analysis on a moderately resistant genotype (TAM428) and a susceptible genotype (Tx2737) to elucidate the molecular mechanisms underlying resistance. Differential expression analysis revealed differences in transcriptomic profile between the two genotypes at multiple time points after infestation by SCA. Six gene clusters had differential expression during SCA infestation. Gene ontology enrichment and cluster analysis of genes differentially expressed after SCA infestation revealed consistent upregulation of genes controlling protein and lipid binding, cellular catabolic processes, transcription initiation, and autophagy in the resistant genotype. Genes regulating responses to external stimuli and stress, cell communication, and transferase activities, were all upregulated in later stages of infestation. On the other hand, expression of genes controlling cell cycle and nuclear division were reduced after SCA infestation in the resistant genotype. These results indicate that different classes of genes, including stress response genes and transcription factors, are responsible for countering the physiological effects of SCA infestation in resistant sorghum plants.

Molecular evidence for the hybrid origin of Rosa lichiangensis (Rosaceae)

Phytotaxa ◽  
2015 ◽  
Vol 222 (3) ◽  
pp. 221 ◽  
Author(s):  
Zhangming Zhu ◽  
Xinfen Gao
Keyword(s):  
Significant Role ◽  
Single Copy ◽  
Morphological Characters ◽  
Molecular Data ◽  
Natural Hybridization ◽  
Hybrid Origin ◽  
Molecular Evidence ◽  
Nuclear Marker

Natural hybridization was assumed to play a significant role in the diversification of Rosa. Rosa lichiangensis was suspected to be of hybrid origin based on its intermediate morphological characters between R. soulieana and R. multiflora var. cathayensis. In this study, four chloroplast regions (ndhC-trnV, ndhF-rpl32, ndhJ-trnF, and psbJ-petA) and a single copy nuclear marker (GAPDH) were used to test the hybrid origin of R. lichiangensis. The results from molecular data supported the hybrid origin of R. lichiangensis and further identified R. soulieana as its maternal progenitor and R. multiflora var. cathayensis as the paternal progenitor.

In vitro insecticidal effect of commercial fatty acids, ß-sitosterol and rutin against the sugarcane aphid, Melanaphis sacchari Zehntner (Hemiptera: Aphididae)

2022 ◽  
Author(s):  
Liliana Aguilar Marcelino ◽  
Jesús Antonio Pineda Alegría ◽  
David Osvaldo Salinas-Sánchez ◽  
Víctor Manuel Hernández Velázquez ◽  
Gonzalo Iván Silva Aguayo ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Positive Control ◽  
Negative Control ◽  
Tween 20 ◽  
Agricultural Pests ◽  
Melanaphis Sacchari ◽  
Insecticidal Effect ◽  
Sugarcane Aphid ◽  
Alternative Means

The sugarcane aphid, Melanaphis sacchari Zehntner (Hemiptera: Aphididae), is the main pest of sorghum, Sorghum bicolor L. Moench (Poaceae), in Mexico. To control this insect, farmers currently use synthetic chemical insecticides, which are toxic to humans and biodiversity. However, natural products are a promising potential source of safer alternative means to control different agricultural pests. The main objective of this study was to evaluate the insecticidal effect of contact by fumigation of pure molecules of four commercial fatty acids (palmitic, stearic, pentadecanoic and linoleic acids), the phytosterol ß -sitosterol, and the flavonoid rutin. The results showed that fatty acids were the most effective against M. sacchari ; the highest mortality rate (85%) was produced by linoleic acid and the LC 50 was 1,181 ppm, followed by stearic and palmitic acids with mortality percentages of 74 and 63%, respectively, at a concentration of 2,500 ppm at 72 h. The positive control, imidacloprid, had 100% mortality in 24 h and the tween 20 negative control exhibited 4% mortality in 72 h. Our results show that commercial fatty acids are effective against adults of M. sacchari , and can be considered an environmentally friendly alternative to the frequent use of synthetic chemical insecticides.

Raoiella of the world (Trombidiformes: Tetranychoidea: Tenuipalpidae)

Zootaxa ◽  
2018 ◽  
Vol 4501 (1) ◽  
pp. 1 ◽  
Author(s):  
JENNIFER J. BEARD ◽  
RONALD OCHOA ◽  
GARY R. BAUCHAN ◽  
CHRISTOPHER POOLEY ◽  
ASHLEY P.G. DOWLING
Keyword(s):  
New Species ◽  
Molecular Evidence ◽  
The World ◽  
Species Separation ◽  
Established Species ◽  
Shared Character

We describe 16 new species and redescribe six established species in the genus Raoiella—R. argenta sp. nov. Beard, R. australica Womersley, R. bauchani sp. nov. Beard & Ochoa, R. calgoa sp. nov. Beard & Ochoa, R. crebra sp. nov. Beard & Ochoa, R. davisi sp. nov. Beard, R. didcota sp. nov. Beard, R. eugeniae (Mohanasundaram), R. goyderi sp. nov. Ochoa & Beard, R. hallingi sp. nov. Beard, R. illyarrie sp. nov. Beard & Ochoa, R. indica Hirst, R. karri sp. nov. Ochoa & Beard, R. macfarlanei Pritchard & Baker, R. marri sp. nov. Beard & Ochoa, R. pandanae Mohanasundaram, R. pooleyi sp. nov. Beard & Ochoa, R. shimpana Meyer, R. tallerack sp. nov. Beard & Ochoa, R. taronga sp. nov. Beard & Ochoa, R. todtiana sp. nov. Beard & Ochoa, R. wandoo sp. nov. Beard & Ochoa. We discuss molecular evidence of species separation, shared character states among groups of species, and patterns in the additions of leg setae throughout ontogeny that occur in the genus. We provide a key to the known species of Raoiella. 

A redefinition of the genus Troglocharinus Reitter, 1908, with description of new species (Coleoptera, Leiodidae, Cholevinae, Leptodirini)

Zootaxa ◽  
2021 ◽  
Vol 4926 (2) ◽  
pp. 151-188
Author(s):  
JAVIER FRESNEDA ◽  
VALERIA RIZZO ◽  
JORDI COMAS ◽  
IGNACIO RIBERA
Keyword(s):  
Phylogenetic Analysis ◽  
New Species ◽  
Phylogenetic Analyses ◽  
Molecular Data ◽  
Valid Species ◽  
Distribution Area ◽  
Undescribed Species ◽  
Separate Species ◽  
Male And Female ◽  
New Material

We redefine the genus Troglocharinus Reitter, 1908 based on a phylogenetic analysis with a combination of mitochondrial and molecular data. We recovered the current Speonomites mengeli (Jeannel, 1910) and S. mercedesi (Zariquiey, 1922) as valid, separate species within the Troglocharinus clade, not directly related to Speonomites Jeannel, 1910, a finding corroborated by a detailed study of the male and female genitalia. In consequence, we reinstate Speonomus mercedesi Zariquiey, 1922 stat. nov. as a valid species, transfer both of them to the genus Troglocharinus, T. mengeli (Jeannel, 1910) comb. nov. and T. mercedesi (Zariquiey, 1922) comb. nov., and redescribe the genus. The study of new material from the distribution area of the former S. mengeli revealed the presence of two undescribed species, T. sendrai sp. nov. and T. fadriquei sp. nov., which we describe herein. We designate the lectotype of Speonomus vinyasi Escolà, 1971 to fix its identity, as among its syntypes there are two different species. In agreement with the results of the phylogenetic analyses we establish the synonymy between the genus Speonomites and Pallaresiella Fresneda, 1998 syn. nv. 

Friend or Foe? The US Invades Grenada

2015 ◽  
pp. 93-144
Author(s):  
Sally-Ann Treharne
Keyword(s):  
Negative Impact ◽  
International Community ◽  
Special Relationship ◽  
Caribbean Island ◽  
The Us ◽  
The Caribbean ◽  
Eastern Caribbean ◽  
Anglo American ◽  
British Commonwealth ◽  
The Uk

The US-led invasion of the Caribbean island of Grenada at the alleged behest of the Organisation of Eastern Caribbean States (OECS) on 25 October 1983 had a profound negative impact upon the development of the Special Relationship under Reagan and Thatcher. The dubious legality of the intervention was widely criticised by the international community, most notably the UK. And yet, it was the Thatcher government that bore the scars of considerable domestic criticism regarding the unlawful US involvement in the internal affairs of a member of the British Commonwealth. The US invasion of Grenada, or operation ‘Urgent Fury’ as it is otherwise known, raised important questions regarding the limits of British credibility and importance within the Anglo-American alliance.

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