scholarly journals Pathogenicity of the fungus Lecanicillium longisporum against Sipha maydis and Metopolophium dirhodum in laboratory conditions

2014 ◽  
Vol 54 (1) ◽  
pp. 67-73 ◽  
Author(s):  
Safoora Fadayivata ◽  
Gholamhossein Moravvej ◽  
Javad Karimi
Keyword(s):  
Field Tests ◽  
Control Program ◽  
Aphid Species ◽  
Cereal Aphids ◽  
Conidial Suspension ◽  
Metopolophium Dirhodum ◽  
Whole Plant ◽  
Conidial Concentration ◽  
Lecanicillium Longisporum ◽  
Aphid Populations

Abstract This study aimed to evaluate the susceptibility of two cereal aphids, Sipha maydis (Passerini) and Metopolophium dirhodum (Walker), to the entomopathogenic fungus, Lecanicillium longisporum (Zimm.) Zare and Gams strain LRC 190, under controlled conditions. The conidial suspension of the fungus was administered using a sprayer on the whole plant over apterous adult aphids. The results indicated that both aphid species were susceptible to L. longisporum and that aphid populations were significantly reduced, compared to the control. Nine days after treatment, the LC50 value of the fungus was obtained as 5.9 × 105 and 3.2 × 106 conidia/ml for S. maydis and M. dirhodum, respectively. The LT50 value of the fungus at a concentration of 108 conidia/ml was obtained as 2.9 and 4.4 days for S. maydis and M. dirhodum, respectively. The results demonstrated that there was a varying susceptibility to the fungus between aphid species. The estimated LC50 and LT50 indicated that L. longisporum was more virulent to S. maydis than to M. dirhodum. The LT50 and R0 decreased as the conidial concentration increased. This is the first study to demonstrate the susceptibility of S. maydis to the entomopathogenic fungi. The present study suggests that L. longisporum has high virulence against the aphids S. maydis and M. dirhodum. Further research with an emphasis on greenhouse and field tests are required, however, before making any decision about using the fungus in a control program

scholarly journals Influence of Plant Diversity on the Numerical Response ofEriopis connexa(Coleoptera: Coccinellidae) to Changes in Cereal Aphid Density in Wheat Crops

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
María C. Tulli ◽  
Dora M. Carmona ◽  
Ana M. Vincini
Keyword(s):  
Plant Diversity ◽  
Aphid Species ◽  
Linear Increase ◽  
Numerical Response ◽  
Cereal Aphids ◽  
Cereal Aphid ◽  
Higher Plant ◽  
Metopolophium Dirhodum ◽  
Aphid Density ◽  
Eriopis Connexa

Cereal aphids cause economic injury to wheat crops. In Argentina,Eriopis connexais an indigenous ladybird. In the present study, the numerical response ofE. connexato changes in aphid density on wheat crops with high and low plant diversity was investigated. The study was carried out in Balcarce, Buenos Aires, Argentina, from September to December 2007 and 2008, on two wheat crops with either a higher plant diversity (HPD) with refuge strips or a lower plant diversity (LPD) without refuge strips. Crops were sampled every week and the abundance of aphids andE. connexawas recorded. The dominant aphid species wereSchizaphis graminum, Metopolophium dirhodum,andSitobion avenae.Eriopis connexashowed a linear increase in the numerical response to an increase in aphid density, which varied in space and time. The abundance ofE. connexaincreased in relation to the crop development and aphid population and was higher in the HPD than in the LPD system. This predator increased its reproductive numerical response only in 2008, with a significant liner response in the HPD system. This suggests that the potential ofE. connexaas a predator of cereal aphids also increases directly in proportion to landscape vegetal diversity.

scholarly journals Abundance of cereal aphids (Hemiptera: Aphididae) within wild Triticum and Aegi­lops spp., and cultivated wheat

1999 ◽  
Vol 35 (No. 2) ◽  
pp. 67-70
Author(s):  
H. Havlíčková ◽  
V. Holubec
Keyword(s):  
Rhopalosiphum Padi ◽  
Significant Negative Correlation ◽  
Aphid Species ◽  
Gene Bank ◽  
Cereal Aphids ◽  
Aegilops Species ◽  
Cereal Aphid ◽  
Metopolophium Dirhodum ◽  
Triticum Species ◽  
The Individual

Accessions of the wild Triticum species: T. boeticum, T. dicoccoides, T. urartu, and the Aegilops species:  Ae. columnaris, Ae. geniculata, Ae. markgrafii, Ae. neglecta and Ae. triuncialis in the collection of the Gene Bank of RICP Prague-Ruzyně, with T.  aestivum cv. Sandra as control, were evaluated for cereal aphid occurrence in the open during 1995–1998 period. The cereal aphid species Rhopalosiphum  padi (RP), Metopolophium dirhodum (MD) and Sitobion avenae (SA) were predominant on the plants. Variations in the abundance of individual aphid species in each year were found. The results from 1997, the optimal year for aphid occurrence, showed differences between both aphid and plant species. RP significantly dominated in Triticum species, while SA preferred Aegilops accessions. A significant negative correlation was found between RP and MD densities in the Triti­ cum spp., while MD and SA occurrence showed a negative relation to that of RP and SA in the Aegilops accessions. The individual aphid species showed a similar pattern of infestation in several genomically close accessions.

Electrophoretic study of enzymes from cereal aphid populations. I. Electrophoretic techniques and staining systems for characterising isoenzymes from six species of cereal aphids (Hemiptera: Aphididae)

1983 ◽  
Vol 73 (4) ◽  
pp. 645-657 ◽  
Author(s):  
H. D. Loxdale ◽  
P. Castañera ◽  
C. P. Brookes
Keyword(s):  
Rhopalosiphum Padi ◽  
Aphid Species ◽  
Individual Species ◽  
Cereal Aphids ◽  
Cereal Aphid ◽  
Metopolophium Dirhodum ◽  
Electrophoretic Study ◽  
Banding Patterns ◽  
Glycerophosphate Dehydrogenase ◽  
Electrophoretic Techniques

AbstractOne–dimensional slab polyacrylamide gel electrophoretic techniques, staining systems and isoenzyme banding patterns for 14 soluble enzymes separated from crude homogenates of individuals of six species of cereal aphids (Sitobion avenae (F.), S. fragariae (Wlk.), Metopolophium dirhodum (Wlk.), M. festucae (Theo.), Rhopalosiphum padi (L.) and R. maidis (Fitch)) are described. The value of the techniques and banding patterns to taxonomic and population genetic studies of these and other aphid species are briefly discussed. With the six species, it was possible to separate the different genera as well as individual species within genera. The enzymes found to be most useful for inter–generic and/or -specific separations were adenylate kinase (AK), esterase (EST), glucose-6-phosphate dehydrogenase (G-6-PDH), hexokinase (HK), malate dehydrogenase (MDH), peptidase (PEP), phosphatase (PHOS), phosphoglucomutase (PMG), 6-phosphogluconate dehydrogenase (6-PGD) and sorbitol dehydrogenase (SORDH), whilst glutamate oxaloacetate transaminase (GOT), α-glycerophosphate dehydrogenase (α-GPD), malic enzyme (ME) and peroxidase (POD) were of relatively little taxonomic use. There were no banding pattern differences between the various morphs of S. avenae (first to fourth-instar nymphs, apterous and alate adults using the 14 enzymes.

STUDY REGARDING THE APHIDOFAGOUS FAUNA STRUCTURE IN THE PEACH ORCHARDS FROM CONSTANTA COUNTY IN 2020

2020 ◽  
Vol 13 ◽  
pp. 110-114
Author(s):  
Andrei Chiriloaie-Palade ◽  
Mădălina Radulea ◽  
Gheorghe Lămureanu ◽  
Ștefan Ion Mocanu ◽  
Maria Iamandei
Keyword(s):  
Myzus Persicae ◽  
Management System ◽  
Green Peach Aphid ◽  
Aphid Species ◽  
Insect Species ◽  
Essential Component ◽  
Intensive Use ◽  
Predatory Insect ◽  
Predatory Insects ◽  
Aphid Populations

"The cosmopolitan aphid species Myzus persicae is a key pest of peach orchards in south and southeastern Romania. The phenomenon of resistance induced by the intensive use of insecticides is a matter of concern for farmers and protectionists, making necessary integrated measure for the control of this pest. Conservation of natural enemy’s populations is an essential component of any management system proposed for pest aphids. The aim of the study was to determine the structure of predatory insects associated with Myzus persicae populations in peach orchards. The research was carried out in three orchards from two localities from Constanta County, in peach plantations with Springcrest variety aged 7, 11 and 12 years. As a result of this study, there were determined a total of 15 predatory insect species belonging to eight systematic families: Coccinellidae, Chrysopidae, Hemerobiidae, Syrphydae, Cecidomyiidae, Panorpidae, Nabidae and Forficulidae, which naturally contribute to the reduction of the green peach aphid populations. "

Drought stress increases the expression of barley defence genes with negative consequences for infesting cereal aphids

2021 ◽  
Author(s):  
Daniel Leybourne ◽  
Tracy Valentine ◽  
Kirsty Binnie ◽  
Anna Taylor ◽  
Alison Jane Karley ◽  
...  
Keyword(s):  
Drought Stress ◽  
Aphid Species ◽  
Susceptible Variety ◽  
Aphid Resistance ◽  
Herbivorous Insects ◽  
Cereal Aphids ◽  
Negative Consequences ◽  
Resistant Plant ◽  
Negative Effect ◽  
The Impact

Crops are exposed to myriad abiotic and biotic stressors with negative consequences. Two stressors that are expected to increase under climate change are drought and infestation with herbivorous insects, including important aphid species. Expanding our understanding of the impact drought has on the plant-aphid relationship will become increasingly important under future climate scenarios. Here we use a previously characterised plant-aphid system comprising a susceptible variety of barley, a wild relative of barley with partial-aphid resistance, and the bird cherry-oat aphid to examine the drought-plant-aphid relationship. We show that drought has a negative effect on plant physiology and aphid fitness and provide evidence to suggest that plant resistance influences aphid responses to drought stress, with the expression of aphid detoxification genes increasing under drought when feeding on the susceptible plant but decreasing on the partially-resistant plant. Furthermore, we show that the expression of thionin genes, plant defensive compounds that contribute aphid resistance, increase ten-fold in susceptible plants exposed to drought stress but remain at constant levels in the partially-resistant plant, suggesting they play an important role in modulating aphid populations. This study highlights the role of plant defensive processes in mediating the interactions between the environment, plants, and herbivorous insects.

Trophic interactions between three species of cereal aphid (Hemiptera: Aphididae) and spring wheat (Poaceae): implications for pest management

2007 ◽  
Vol 139 (6) ◽  
pp. 850-863 ◽  
Author(s):  
Samuel M. Migui ◽  
Robert J. Lamb
Keyword(s):  
Spring Wheat ◽  
Trophic Interactions ◽  
Plant Biomass ◽  
Rhopalosiphum Padi ◽  
Aphid Species ◽  
Economic Damage ◽  
Cereal Aphids ◽  
Cereal Aphid ◽  
Economic Thresholds ◽  
Specific Impact

AbstractThe susceptibilities of genetically diverse Canadian spring wheats, Triticum aestivum L. and Triticum durum Desf., to three aphid species, Rhopalosiphum padi (L.), Sitobion avenae (Fabricius), and Schizaphis graminum (Rondani), were investigated. Trophic interactions measured as changes in biomass of aphids and wheat plants were used to quantify levels of resistance, components of resistance, and impact of aphids on yield. Plants in field cages were infested with small numbers of aphids for 21 days at heading. These plants were usually more suitable for the development of S. avenae and S. graminum than of R. padi. Partial resistance, measured as seed production by infested plants as a proportion of that by a control, varied from 11% to 59% for different aphid species and wheat classes when all wheat plants were infested at the same stage. Cultivars within wheat classes responded similarly to each of the aphid species. None of the wheat cultivars showed agriculturally effective levels of antibiosis. The specific impact of each aphid species and wheat class varied from 5 to 15 mg of plant biomass lost for each milligram of biomass gained by the aphids. Canadian Western Red Spring wheat had a lower specific impact and therefore was more tolerant to aphids than the other two classes, but not tolerant enough to avoid economic damage at the aphid densities observed. Plants did not compensate for feeding damage after aphid feeding ceased, based on the higher specific impacts observed for mature plants than for plants that were heading. The interactions between aphids and plants show that current economic thresholds probably underestimate the damage caused by cereal aphids to Canadian spring wheat.

scholarly journals Virulence of Two Entomophthoralean Fungi, Pandora neoaphidis and Entomophthora planchoniana, to Their Conspecific (Sitobion avenae) and Heterospecific (Rhopalosiphum padi) Aphid Hosts

Insects ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 54 ◽  
Author(s):  
Ibtissem Ben Fekih ◽  
Annette Bruun Jensen ◽  
Sonia Boukhris-Bouhachem ◽  
Gabor Pozsgai ◽  
Salah Rezgui ◽  
...  
Keyword(s):  
Fungal Pathogens ◽  
Rhopalosiphum Padi ◽  
Aphid Species ◽  
Sitobion Avenae ◽  
Cereal Aphids ◽  
Infection Level ◽  
Initial Exposure ◽  
Pandora Neoaphidis ◽  
First Time ◽  
Aphid Host

Pandora neoaphidis and Entomophthora planchoniana (phylum Entomophthoromycota) are important fungal pathogens on cereal aphids, Sitobion avenae and Rhopalosiphum padi. Here, we evaluated and compared for the first time the virulence of these two fungi, both produced in S. avenae cadavers, against the two aphid species subjected to the same exposure. Two laboratory bioassays were carried out using a method imitating entomophthoralean transmission in the field. Healthy colonies of the two aphid species were exposed to the same conidial shower of P. neoaphidis or E. planchoniana, in both cases from a cadaver of S. avenae. The experiments were performed under LD 18:6 h at 21 °C and a successful transmission was monitored for a period of nine days after initial exposure. Susceptibility of both S. avenae and R. padi to fungal infection showed a sigmoid trend. The fitted nonlinear model showed that the conspecific host, S. avenae, was more susceptible to E. planchoniana infection than the heterospecific host R. padi, was. In the case of P. neoaphidis, LT50 for S. avenae was 5.0 days compared to 5.9 days for R. padi. For E. planchoniana, the LT50 for S. avenae was 4.9 days, while the measured infection level in R. padi was always below 50 percent. Our results suggest that transmission from conspecific aphid host to heterospecific aphid host can occur in the field, but with expected highest transmission success to the conspecific host.

scholarly journals Comparison of Field Population Growths of Three Cereal Aphid Species on Winter Wheat

2011 ◽  
Vol 39 (No. 2) ◽  
pp. 61-64 ◽  
Author(s):  
V. Jarošík ◽  
A. Honěk ◽  
A. Tichopád
Keyword(s):  
Winter Wheat ◽  
Rhopalosiphum Padi ◽  
Intrinsic Rate ◽  
Aphid Species ◽  
Population Increase ◽  
Intrinsic Rate Of Increase ◽  
Cereal Aphid ◽  
Metopolophium Dirhodum ◽  
Aphid Density ◽  
Rate Of Increase

Population growths of three aphid species colonising winter wheat stands, Metopolophium dirhodum, Rhopalosiphum padi and Sitobion avenae, were analysed by regression method. The calculations were based on counts in 268 winter wheat plots at 3 or 7 day intervals over 10 (leaves) or 6 (ears) years. The population dynamics of a particular species differed widely between years. Density independent exponential growth of the population was most common, but its rate differed significantly between species, and for S. avenae also between populations on leaves and ears, on which the populations grew fastest. Field estimates of the intrinsic rate of increase derived from the exponential growths ranged between 0.010–0.026 in M. dirhodum, 0.0071–0.011 in R. padi, and between 0.00078–0.0061 and 0.0015–0.13 in S. avenae on leaves and ears, respectively. In the populations with the most vigorous population growth, S. avenae on ears and M. dirhodum on leaves, the rate of population increase significantly decreased with increasing aphid density.  

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