scholarly journals Genetic Variability of Stolbur Phytoplasma inHyalesthes obsoletus(Hemiptera: Cixiidae) and its Main Host Plants in Vineyard Agroecosystems

2015 ◽  
Vol 108 (4) ◽  
pp. 1506-1515 ◽  
Author(s):  
Lucia Landi ◽  
Paola Riolo ◽  
Sergio Murolo ◽  
Gianfranco Romanazzi ◽  
Sandro Nardi ◽  
...  
Keyword(s):  
Genetic Variability ◽  
Host Plants ◽  
Main Host ◽  
Stolbur Phytoplasma

scholarly journals Diversity of fruit fly (Diptera: Tephritidae) species in French Guiana: their main host plants and associated parasitoids during the period 1994–2003 and prospects for management

Fruits ◽  
2013 ◽  
Vol 68 (3) ◽  
pp. 219-243 ◽  
Author(s):  
Jean-François Vayssières ◽  
Jean-Pierre Cayol ◽  
Philippe Caplong ◽  
Julien Séguret ◽  
David Midgarden ◽  
...  
Keyword(s):  
Host Plants ◽  
French Guiana ◽  
Fruit Fly ◽  
Main Host

Phoma medicaginis. [Descriptions of Fungi and Bacteria].

2002 ◽  
Author(s):  
G. C. Kinsey
Keyword(s):  
Geographical Distribution ◽  
Root Rot ◽  
Host Plants ◽  
Stem Canker ◽  
Seedling Blight ◽  
Plant Debris ◽  
Wide Range ◽  
Main Host ◽  
Phoma Medicaginis ◽  
Rain Splash

Abstract A description is provided for Phoma medicaginis. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. DISEASE: Probably an opportunisitic pathogen and saprobe, while var. macrospora is more strongly pathogenic towards M. sativa. Contributory to causing (spring) black stem of forage legumes (mainly Medicago, possibly also Melilotus and Trifolium), involving seedling blight, stem canker, root rot and leaf spot. It develops as long dark lesions on petioles and stems, later encircling whole stems and spreading to cause crown and foot rot. HOSTS: On leaves, petioles, stems, roots and seeds of possibly a wide range of plants. However, many records require verification. The main host plant is Medicago sativa (alfalfa, lucerne), but also recorded on Melilotus and other Papilionaceae, including Arachis, Cicer, Glycine, Lathyrus, Lens, Phaseolus, Pisum, Trifolium, Trigonella, Vicia and Vigna. Non-leguminous host plants include Anacardium, Annona, Beta, Brassica, Chrysanthemum, Curcuma, Cyperus, Fragaria, Juniperus, Lycopersicon, Madhuca, Nicotiana, Phlox, Saccharum, Solanum, Striga, Themeda, Zea and Zinnia. Also reported from soil and indeterminate plant debris and from human scalp. While many records refer only to P. medicaginis s. lat., records for var. macrospora appear to indicate that it occurs more specifically on M. sativa. GEOGRAPHICAL DISTRIBUTION: AFRICA: Egypt, Kenya, Libya, Malawi, Nigeria, Sudan, Zambia, Zimbabwe. NORTH AMERICA: Canada, USA. CENTRAL AMERICA: West Indies. SOUTH AMERICA: Argentina. ASIA: Bangladesh, Bhutan, India, Saudi Arabia, Syria, Thailand. AUSTRALASIA: Australia, New Zealand. EUROPE: Denmark, Great Britain, Italy, Latvia, Netherlands. TRANSMISSION: Soil-borne on plant debris with infection of new plants by rain splash. Probably also seed-borne if pods become infected.

Identification and phenology of Hyalesthes obsoletus (Hemiptera: Auchenorrhyncha: Cixiidae) nymphal instars

2012 ◽  
Vol 102 (5) ◽  
pp. 504-514 ◽  
Author(s):  
E. Cargnus ◽  
F. Pavan ◽  
N. Mori ◽  
M. Martini
Keyword(s):  
Host Plants ◽  
Morphological Characteristics ◽  
Flight Period ◽  
Correct Identification ◽  
Convolvulus Arvensis ◽  
Bois Noir ◽  
Morphological Studies ◽  
First Instar ◽  
Main Host ◽  
Hyalesthes Obsoletus

AbstractUrtica dioica and Convolvulus arvensis are the main host plants of Hyalesthes obsoletus and play an important role in the epidemiology of Bois noir of grapevines. The earliest survey, which was carried out to compare the phenology of nymphal instars on U. dioica and C. arvensis, had highlighted some problems in the identification of the instars. Therefore, the correct identification of nymphs to species and instar level became a preliminary aim of this research. Adults and nymphs attributable to H. obsoletus were collected during 2008–2010 in three flatland vineyard habitats of northern Italy on U. dioica, C. arvensis and Artemisia verlotorum. Nymphs and morphologically identified adults of H. obsoletus were submitted to molecular identification. Morphometric and morphological studies were carried out on nymphs collected in the field or obtained in laboratory rearings. Molecular methods not only confirmed the identity of adults, but also allowed the assignment of the nymphs to this species. Morphometric and morphological characteristics (e.g. body and head-thoracic lengths, number of thoracic pits) showed the existence of five nymphal instars. Morphometric differences between newly hatched and older first-instar nymphs were observed. A key to distinguish the five instars was proposed. Evident differences between H. obsoletus nymphs studied here and elsewhere were identified. According to differences in adult-flight period, an earlier phenology of nymphs on C. arvensis than on U. dioica was observed. In particular, the typical overwintering instar was the second on U. dioica and the third on C. arvensis.

scholarly journals Temporal Variation of Membracidae (Hemiptera: Auchenorrhyncha) Composition in Areas of Caatinga with Different Vegetation Structures

Sociobiology ◽  
2016 ◽  
Vol 63 (2) ◽  
pp. 826 ◽  
Author(s):  
Antonio Creão-Duarte ◽  
Malva Hernández ◽  
Rembrandt Rothéa ◽  
Wellington Santos
Keyword(s):  
Cluster Analysis ◽  
Temporal Variation ◽  
Rainy Season ◽  
Host Plants ◽  
Abundant Species ◽  
Caatinga Vegetation ◽  
Main Host ◽  
Dry Seasons ◽  
Vegetation Structures ◽  
Dry And Rainy Seasons

The diversity of membracids in different Caatinga vegetation structures (preserved, intermediate and degraded) was studied during dry and rainy seasons in 2006. We recorded 1,107 individuals, belonging to 13 species, mostly during the rainy season (693). Melusinella nervosa (Fairmaire, 1846), Enchenopa brasiliensis Strümpel, 2007 and E. eunicea Creão-Duarte & Rothéa, 2007 were the most abundant species, although this pattern varied in the three areas. M. nervosa and E. brasiliensis were the most abundant during the rainy and dry seasons, respectively, due to the resistance of its main host plant to seasonality and climate rigors. Thrasymedes pallescens (Stål, 1869) was the species least affected by seasonality, with 51.3% and 48.7% of the specimens collected in the rainy and dry seasons, respectively, followed by E. eunicea, with 65.6% and 34.4%. A cluster analysis showed that membracids from preserved areas in the dry season were more related to the ones from rainy season, highlighting the importance of these areas in the Caatinga for maintenance of these insects, which are strongly associated with their host plants.

scholarly journals Differences in the level of intraspecific genetic variability in taxons of aphids, differing by character of evolutionary dynamics

2017 ◽  
pp. 20-25
Author(s):  
M. M. Varabyova ◽  
N. V. Voronova
Keyword(s):  
Life Cycle ◽  
Genetic Variability ◽  
Host Plant ◽  
Host Plants ◽  
Evolutionary Dynamics ◽  
Wide Spectrum ◽  
Nucleotide Sequences ◽  
Coi Gene ◽  
Host Plant Specialization ◽  
High Level

Aim. Aphids are an interesting model to study the level of the genetic variability since there are species, which differ in the level of host-plant specialization and the peculiarity of a life cycle among them. The mutations observed in COI gene allow defining the interspecific level of the genetic variability in aphids. Methods. The highly conservative COI gene was used to study the level of the genetic variability in aphids. Results. The analysis of nucleotide sequences of COI gene allowed discovering statistically significant differences between generalists with wide spectrum of host plants, generalists with narrow spectrum of host plants and specialists. In addition, the genetic differences were discovered between holocyclic and angolocyclic species of aphids. Conclusions. As a result of the work it was determined that the wide spectrum of host-plants and holocycly are associated with the high level of genetic variability of COI gene in aphids.Keywords: aphids, genetic variability, COI, life cycle, host-plant specialization.

scholarly journals Meteorus gyrator (Thunberg) (Hymenoptera: Braconidae) In Egypt: Geographical Distribution and Mass-production

2020 ◽  
pp. 34-42 ◽  
Author(s):  
Mohamed Ahmed Gesraha ◽  
Amany Ramadan Ebeid
Keyword(s):  
Mass Production ◽  
Host Plants ◽  
Heliothis Armigera ◽  
Mass Rearing ◽  
Abundant Species ◽  
Insect Larvae ◽  
Main Host ◽  
Sesamia Cretica ◽  
Heliothis Spp ◽  
Basic Biology

Background: The larval internal parasitoids in the genus Meteorus attack certain lepidopterous larvae in different Egyptian fields. Two species, M. rubens and M. gyrator were the most abundant species reared from several lepidopterous larval species, which feed on different host plants in the two selected Governorates in Egypt throughout two successive years. Aim: This work presents a method specifically designed to improve the abundance and the parasitizing potential of M. gyrator in open fields to parasitize and develop on a broad range of noctuid’s pests by releasing considerable number of the parasitoid adults. Also it deals with some aspects of the basic biology of M. gyrator parasitizing Spodoptera littoralis and Autugrapha ni, as mass-rearing hosts. Methodology: 1- Population Dynamics Biweekly samples of lepidopterous larvae were collected from different host plants in the fields of Giza and Faiyum Governorates, for two successive years (November, 2017 to October, 2019). Collected larvae were confined individually under constant conditions until pupation or the emergence of the internal parasitoid’s larvae for pupation. 2- Laboratory Rearing Cultures of some insect larvae, Heliothis armigera, Spodoptera exigua, Agrotis ipsilon, Sesamia cretica, S. littoralis and Autographa ni were reared in laboratory under constant conditions to act as hosts for mass-production of the parasitoid, M. gyrator. Results: Obtained results reveal that A. ipsilon was the main host of M. rubens, it was more abundant in both years and localities of the survey. Meteorus gyrator was recorded at fewer numbers; it was reared from S. littoralis, S. exigua, S. critica, Heliothis spp. and Autographa spp. The parasitism percentage by M. rubens averaged 23.10% at Giza. While in the case of M. gyrator it averaged 3.25%. In Faiyum, the corresponding figure averaged 12.96% parasitism for M. rubens; while it averaged 6.93%, for M. gyrator. To increase the efficacy of M. gyrator, mass production experiments were carried out, suggesting that Autographa ni was the most suitable for mass-rearing than S. littoralis. Conclusion: To increase the efficacy of M. gyrator as an endoparasitoid, its numbers in the field should be increased by releasing a considerable number of adults, to control lepidopterous larval pests.

scholarly journals Evaluation of Some Reproductive and Developmental Parameters of Paracoccus Marginatus (Hemiptera: Pseudococcidae) Under Laboratory Conditions

2020 ◽  
Vol 8 (3) ◽  
pp. 912
Author(s):  
Yawavi Eyram Gnomou ◽  
Seth Wolali Nyamador ◽  
Komina Amevoin ◽  
Obinna Ajuonu ◽  
Georg Goergen ◽  
...  
Keyword(s):  
Host Plants ◽  
Reproductive Activity ◽  
Economic Importance ◽  
Potential Threat ◽  
Local Conditions ◽  
Diverse Range ◽  
Larval Stages ◽  
Great Economic Importance ◽  
Main Host ◽  
Third Stage

The papaya mealybug Paracoccus marginatus Williams and Granara De Willink (Hemiptera: Pseudococcidae) is an invasive insect species attacking a diverse range of host plants. It causes an enormous damage to crops including those of very great economic importance including the papaya, being its main host. Considering its potential threat to fruit and crops of economic importance throughout Togo, this study, which was carried out in the laboratory under conditions of 28 ± 2°C, 75 ± 5% RH, 12 : 12 LD, made it possible to determine some biological parameters of P. marginatus, essential for the implementation of management programmes for this species. The results showed that a female of P. marginatus had three periods of reproductive activity, namely pre-oviposition, oviposition and post-oviposition periods which last on average 7.74 ± 1.26; 6.13 ± 3.02 and 7.45 ± 4.27 days respectively. During oviposition, a female P. marginatus lays an average of 25.262 ± 11.16 eggs per day, for an average total of 224.32 ± 29.99 eggs during her lifetime, which averages 18.44 ± 3.31 days. During the post-embryonic development of P. marginatus which lasts on average 25.98 ± 4.47 days for the female against 29.70 ± 5.58 days for the male and which passes through three larval stages, the important mortality rates of the first and second larval stages were noted. They are estimated to an average of 61.40 ± 0.05 and 52.8 ± 0.025 respectively. However, at the third stage, the rate is 35.02 ± 0.03 for the female and zero for the male. These results provide a better understanding of the biology of P. marginatus under local conditions and thus provide a basis for controlling the population of the species and the damage it causes in Togo.

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