Geographic distribution, host range and perennation of Cotesia sesamiae and Cotesia flavipes Cameron in cultivated and natural habitats in Kenya

2010 ◽  
Vol 54 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Duna Madu Mailafiya ◽  
Bruno Pierre Le Ru ◽  
Eunice Waitherero Kairu ◽  
Paul-André Calatayud ◽  
Stéphane Dupas
Keyword(s):  
Host Range ◽  
Geographic Distribution ◽  
Cotesia Flavipes ◽  
Cotesia Sesamiae ◽  
Natural Habitats

scholarly journals Identification of Phytoplasmas Representing Multiple New Genetic Lineages from Phloem-Feeding Leafhoppers Highlights the Diversity of Phytoplasmas and Their Potential Vectors

Pathogens ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 352
Author(s):  
Wei Wei ◽  
Valeria Trivellone ◽  
Christopher H. Dietrich ◽  
Yan Zhao ◽  
Kristi D. Bottner-Parker ◽  
...  
Keyword(s):  
Host Range ◽  
Quantitative Polymerase Chain Reaction ◽  
Rflp Analysis ◽  
Natural Habitats ◽  
Genetic Lineages ◽  
Genetic Subgroup ◽  
Polymerase Chain ◽  
Phloem Feeding ◽  
Fresh Insight

Phytoplasmas are obligate transkingdom bacterial parasites that infect a variety of plant species and replicate in phloem-feeding insects in the order Hemiptera, mainly leafhoppers (Cicadellidae). The insect capacity in acquisition, transmission, survival, and host range directly determines the epidemiology of phytoplasmas. However, due to the difficulty of insect sampling and the lack of follow-up transmission trials, the confirmed phytoplasma insect hosts are still limited compared with the identified plant hosts. Recently, quantitative polymerase chain reaction (qPCR)-based quick screening of 227 leafhoppers collected in natural habitats unveiled the presence of previously unknown phytoplasmas in six samples. In the present study, 76 leafhoppers, including the six prescreened positive samples, were further examined to identify and characterize the phytoplasma strains by semi-nested PCR. A total of ten phytoplasma strains were identified in leafhoppers from four countries including South Africa, Kyrgyzstan, Australia, and China. Based on virtual restriction fragment length polymorphism (RFLP) analysis, these ten phytoplasma strains were classified into four distinct ribosomal (16Sr) groups (16SrI, 16SrIII, 16SrXIV, and 16SrXV), representing five new subgroups (16SrI-AO, 16SrXIV-D, 16SrXIV-E, 16SrXIV-F, and 16SrXV-C). The results strongly suggest that the newly identified phytoplasma strains not only represent new genetic subgroup lineages, but also extend previously undiscovered geographical distributions. In addition, ten phytoplasma-harboring leafhoppers belonged to seven known leafhopper species, none of which were previously reported insect vectors of phytoplasmas. The findings from this study provide fresh insight into genetic diversity, geographical distribution, and insect host range of phytoplasmas. Further transmission trials and screening of new potential host plants and weed reservoirs in areas adjacent to collection sites of phytoplasma harboring leafhoppers will contribute to a better understanding of phytoplasma transmission and epidemiology.

Host range and geographic distribution of pangola stunt virus and its planthopper vectors in Australia

1991 ◽  
Vol 42 (5) ◽  
pp. 819 ◽  
Author(s):  
DS Teakle ◽  
S Hicks ◽  
M Karan ◽  
JB Hacker ◽  
RS Greber ◽  
...  
Keyword(s):  
Host Range ◽  
Geographic Distribution ◽  
Field Surveys ◽  
Natural Hosts ◽  
Digitaria Eriantha

Natural hosts of pangola stunt virus (PaSV) in eastern Austalia were found to be Digitaria eriantha ssp. pentzii (pangola grass), D. ciliaris (summer grass) and D. milanjiana. Transmission tests using the planthopper vector, Sogatella kolophon, showed that D. polevansii, D. eriantha ssp. eriantha, D. swazilandensis and the Australian native, D. divaricatissima were also susceptible, whereas D. didactyla was not infected. In tests of 22 species in 15 other genera, only Urochloa panicoides (annual urochloa grass) was infected. In field surveys, PaSV was commonly found in pangola grass in near-coastal districts from Grafton, N.S.W. to Walkamin, N. Qld and was detected up to 100 km inland at Toowoomba. The virus was not detected in either pangola grass or D. eriantha ssp. eriantha in subhumid areas west of Toowoomba or at Gayndah. Sogatella kolophon was collected from Bamaga, N. Qld to Murwillumbah, N.S.W. It was commonly associated with both PaSV-infected and PaSV-free digitgrass pastures. It is concluded that PaSV poses a threat to many digitgrasses in near-coastal districts of Qld and subtropical N.S.W., but so far is unknown in inland Australia.

Detection and Identification of Botrytis Species Associated with Neck Rot, Scape Blight, and Umbel Blight of Onion

2006 ◽  
Vol 7 (1) ◽  
pp. 38 ◽  
Author(s):  
Martin I. Chilvers ◽  
Lindsey J. du Toit
Keyword(s):  
Host Range ◽  
Geographic Distribution ◽  
Detection And Identification ◽  
And Storage ◽  
Symptoms And Signs ◽  
Methods Of Isolation

Diagnosis of detection and identification of Botrytis species associated with neck rot, scape blight, and umbel blight of onion are discussed in detail, including the disease's symptoms and signs, host range, taxonomy, and geographic distribution, as well as methods of isolation, identification (including macroscopic vs. microscopic characteristics), and storage of the pathogens. Accepted for publication 7 August 2006. Published 27 November 2006.

Nematodes and cestodes of rodents in South Africa: baseline data on diversity and geographic distribution

2019 ◽  
Vol 94 ◽  
Author(s):  
A. Spickett ◽  
K. Junker ◽  
G. Froeschke ◽  
V. Haukisalmi ◽  
S. Matthee
Keyword(s):  
South Africa ◽  
Host Range ◽  
Geographic Distribution ◽  
Host Species ◽  
Baseline Data ◽  
Helminth Species ◽  
Rodent Species ◽  
Helminth Parasites ◽  
Gastrointestinal Helminths ◽  
Naturally Occurring

Abstract Currently, descriptive information on the host range and geographic distribution of helminth parasites associated with naturally occurring rodents in South and southern Africa is scant. Therefore, we embarked on a countrywide study to: (1) identify gastrointestinal helminths and their host range, and (2) provide baseline data on the geographic distribution of helminths across the country. Altogether, 55 helminth taxa were recovered from at least 13 rodent species (n = 1030) at 26 localities across South Africa. The helminth taxa represented 25 genera (15 nematodes, nine cestodes and one acanthocephalan). Monoxenous nematodes were the most abundant and prevalent group, while the occurrence of heteroxenous nematodes and cestodes was generally lower. The study recorded several novel helminth–host associations. Single-host-species infections were common, although multiple-host-species infections by helminth species were also recorded. Monoxenous nematodes and some cestodes were recovered countrywide, whereas heteroxenous nematodes were restricted to the eastern regions of South Africa. The study highlights the as yet unexplored diversity of helminth species associated with naturally occurring rodent species and provides initial data on their geographical distribution in South Africa.

Host range and geographic distribution of Armillaria root rot pathogens in the Canadian prairie provinces

1990 ◽  
Vol 20 (12) ◽  
pp. 1859-1863 ◽  
Author(s):  
K. I. Mallett
Keyword(s):  
Host Range ◽  
Geographic Distribution ◽  
Host Species ◽  
Root Rot ◽  
Boreal Forests ◽  
Common Species ◽  
Canadian Prairie ◽  
Armillaria Root Rot ◽  
Armillaria Species ◽  
Prairie Provinces

A survey to identify Armillaria root rot pathogens, their host range, and geographic distribution was conducted in the Canadian prairie provinces. Collections of basidiocarps and isolates from the wood of gymptomatic or dead trees were made. Armillaria species were identified by interfertility testing and by the L-DOPA method. Three Armillaria species, A. ostoyae (Romagn.) Herink, A. sinapina Bérubé & Dessureault, and A. calvescens Bérubé & Dessureault, were identified. Armillariaostoyae was the most common species in both the subalpine and boreal forests and was found on a wide variety of coniferous and deciduous host species. Armillariasinapina was in both the boreal and subalpine forests but occurred primarily on deciduous host species. Armillariacalvescens was rare and was found only in the boreal forest on both coniferous and deciduous host species.

scholarly journals Comparative evaluation of Cotesia flavipes and C. sesamiae (Hymenoptera: Braconidae) for the management of Chilo partellus (Lepidoptera: Pyralidae) in Kenya

1999 ◽  
Vol 89 (2) ◽  
pp. 185-191 ◽  
Author(s):  
M.N. Sallam ◽  
W.A. Overholt ◽  
E. Kairu
Keyword(s):  
Chilo Partellus ◽  
Sesamia Calamistis ◽  
Cotesia Flavipes ◽  
Cotesia Sesamiae ◽  
Female Progeny ◽  
Northern Tanzania ◽  
Significant Difference ◽  
Total Progeny ◽  
Lepidoptera Pyralidae ◽  
Searching Ability

AbstractCotesia flavipes Cameron, a gregarious larval endoparasitoid native to the Indo-Australian region, was imported from Pakistan and released in Kenya in 1993 for management of the exotic stemborer, Chilo partellus (Swinhoe). Recent reports confirmed the successful establishment of the parasitoid in three locations in Kenya and in northern Tanzania. Functional response studies on this parasitoid and an indigenous congener, Cotesia sesamiae (Cameron), indicated that C. flavipes had a higher searching ability and attacked more larvae when Chilo partellus was the host. When a native stemborer, Sesamia calamistis Hampson, was the host, there was no significant difference between numbers attacked by both parasitoids. Numerical response studies showed that Cotesia flavipes produced more total progeny and female progeny per female parasitoid on Chilo partellus than did Cotesia sesamiae. No significant difference in progeny production was detected between the two parasitoids on S. calamistis. Functional and numerical responses tested in the laboratory gave the same ranking of the two parasitoids on the two hosts as in the field. This study suggests that Cotesia flavipes is a more efficient parasitoid and it is anticipated that it will contribute to the control of both exotic and native stemborers in Kenya.

Geographic Distribution and Host Range of Lethal Bronzing Associated with Phytoplasma Subgroup 16SrIV-D on Palms in Southern Louisiana

2020 ◽  
Vol 21 (4) ◽  
pp. 350-355
Author(s):  
Mary Helen Ferguson ◽  
Raghuwinder Singh ◽  
Madeline Cook ◽  
Timothy Burks ◽  
Kevin Ong
Keyword(s):  
Host Range ◽  
New Orleans ◽  
Geographic Distribution ◽  
Small Proportion ◽  
Canary Island ◽  
Date Palm ◽  
Date Palms ◽  
Phoenix Canariensis ◽  
Sabal Palmetto ◽  
City Park

Lethal bronzing (LB), also previously known as date palm lethal decline or Texas Phoenix palm decline, associated with phytoplasma subgroup 16SrIV-D, was first identified in Louisiana in December 2013. A survey of palms showed that the disease was not only confined to City Park in New Orleans, where it was first detected, but is present in other parts of Orleans Parish, as well as two adjacent parishes. Canary Island date palms (Phoenix canariensis) tested positive at the highest frequency, and some edible date palms (P. dactylifera) and a small proportion of cabbage palms (Sabal palmetto) tested positive as well. Symptoms do not appear to be a reliable indicator of LB, because a substantial proportion of palms indicated as symptomatic tested negative. Furthermore, not all infected palms showed symptoms. Since the palm survey conducted in 2015 to 2016, LB has positively been identified from silver date palm (P. sylvestris) and Chinese windmill palm (Trachycarpus fortunei) in three additional parishes in Louisiana.

scholarly journals Genomic divergence footprints in the bracovirus of Cotesia sesamiae identified by targeted re-sequencing approach

2017 ◽  
Author(s):  
Jérémy Gauthier ◽  
Philippe Gayral ◽  
Bruno Pierre Le Ru ◽  
Séverine Jancek ◽  
Stéphane Dupas ◽  
...  
Keyword(s):  
Host Range ◽  
Parasitoid Wasp ◽  
Gene Families ◽  
Genetic Variations ◽  
Genomic Region ◽  
Loss Of Function ◽  
Cotesia Sesamiae ◽  
Large Deletions ◽  
Branch Site

AbstractThe African parasitoid wasp Cotesia sesamiae is structured in contrasted populations showing differences in host range and the recent discovery of a specialist related species, C. typhae, provide a good framework to study the mechanisms that link the parasitoid and their host range. To investigate the genomic bases of divergence between these populations, we used a targeted sequencing approach on 24 samples. We targeted a specific genomic region encoding the bracovirus, which is deeply involved in the interaction with the host. High sequencing coverage was obtained for all samples allowing the study of genetic variations between wasp populations and species. Combining population genetic estimations, the diversity (π), the relative differentiation (FST) and the absolute differentiation (dxy), and branch-site dN/dS measures, we identified six divergent genes impacted by positive selection belonging to different gene families. These genes are potentially involved in host adaptation and in the specialization process. Fine scale analyses of the genetic variations also revealed deleterious mutations and large deletions on certain genes inducing pseudogenization and loss of function. These results highlight the crucial role of the bracovirus in the molecular interactions between the wasp and its hosts and in the evolutionary processes of specialization.

scholarly journals Cryptic fungal species unmasked

2012 ◽  
Vol 33 (1) ◽  
pp. 36 ◽  
Author(s):  
Roger G Shivas ◽  
Lei Cai
Keyword(s):  
Host Range ◽  
Cryptic Species ◽  
Geographic Distribution ◽  
Dna Sequences ◽  
Fungal Species ◽  
Phylogenetic Methods ◽  
Molecular Phylogenetic

The word cryptic is derived from the Greek adjective krupt�s which means hidden. Morphologically indistinguishable species that have been revealed by molecular phylogenetic methods, and 37ultimately only recognised by their DNA sequences, are referred to as cryptic species. The importance of cryptic species for plant pathologists is that they may have significant differences in the severity of diseases they cause, host range and geographic distribution. It is these differences that are of concern to many biosecurity agencies, particularly in Australia.

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