DOCSLIB.ORG

Obligate Bacterial Endosymbionts Limit Thermal Tolerance of Insect Host Species

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Obligate Bacterial Endosymbionts Limit Thermal Tolerance of Insect Host Species Obligate bacterial endosymbionts limit thermal tolerance of insect host species Bo Zhanga,b, Sean P. Leonardb, Yiyuan Lib, and Nancy A. Moranb,1 aLaboratory of Predatory Mites, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, 100193 Beijing, People’s Republic of China; and bDepartment of Integrative Biology, University of Texas, Austin, TX 78712 Edited by David L. Denlinger, The Ohio State University, Columbus, OH, and approved October 22, 2019 (received for review September 6, 2019) The thermal tolerance of an organism limits its ecological and acid replacements, including replacements that affect translational geographic ranges and is potentially affected by dependence on machinery itself, leading to decline in protein quality (9). temperature-sensitive symbiotic partners. Aphid species vary widely Aphids and their intracellular bacterial associates Buchnera in heat sensitivity, but almost all aphids are dependent on the aphidicola are a widely studied model of obligate symbiosis. nutrient-provisioning intracellular bacterium Buchnera, which has Buchnera has diversified with aphids through maternal trans- evolved with aphids for 100 million years and which has a reduced mission for >100 million years; their tiny genomes encode only genome potentially limiting heat tolerance. We addressed whether 354–587 proteins (10) but retain genes underlying production of heat sensitivity of Buchnera underlies variation in thermal tolerance amino acids needed for host nutrition (11). Several observations among 5 aphid species. We measured how heat exposure of juve- suggest that Buchnera is heat sensitive. First, Buchnera proteins nile aphids affects later survival, maturation time, and fecundity. At show reduced thermal stability compared to homologous pro- one extreme, heat exposure of Aphis gossypii enhanced fecundity teins of related free-living bacteria (12). Second, as in other in- and had no effect on the Buchnera titer. In contrast, heat suppressed sect endosymbionts (6), Buchnera shows constitutively elevated Buchnera populations in Aphis fabae, which suffered elevated mor- expression of heat shock proteins including GroEL and DnaK; tality, delayed development and reduced fecundity. Likewise, in high expression of these chaperones rescues misfolded proteins Acyrthosiphon kondoi and Acyrthosiphon pisum, heat caused rapid in a destabilized proteome (13). Functionality of Buchnera en- declines in Buchnera numbers, as well as reduced survivorship, de- zymes expressed in Escherichia coli requires overexpression of velopment rate, and fecundity. Fecundity following heat exposure is GroEL (14) or growth at lower temperature (15). Third, in the EVOLUTION severely decreased by a Buchnera mutation that suppresses the transcriptional response of a gene encoding a small heat shock pro- pea aphid, Ac. pisum, some Buchnera genotypes are especially tein. Similarly, absence of this Buchnera heat shock gene may ex- susceptible to heat due to a recurring mutation in the heat shock plain the heat sensitivity of Ap. fabae. Fluorescent in situ hybridization promoter of ibpA, which encodes a universal small heat shock revealed heat-induced deformation and shrinkage of bacteriocytes in protein (16, 17). Aphids with this haplotype lose all or most heat-sensitive species but not in heat-tolerant species. Sensitive and Buchnera following heat exposure and suffer drastic reductions tolerant species also differed in numbers and transcriptional responses in fecundity; experimental replacement of this haplotype improves of heat shock genes. These results show that shifts in Buchnera heat heat tolerance (18). Fourth, the facultative symbiont, Serratia sensitivity contribute to host variation in heat tolerance. symbiotica, which ameliorates the negative effects of heat on Ac. symbiosis | aphididae | thermal adaptation | RNA-Seq | heat shock proteins Significance hermal tolerance is a basic determinant of an organism’s The ability to withstand heat is fundamental to an organism’s Tecology: The ability to survive and to reproduce in the face of ecology, and variation in heat tolerance affects the geographic variation in temperature affects geographic range, competitive range of species. Many insects have obligate relationships with ability, and population dynamics. Many animals and plants engage heat-sensitive bacterial symbionts, raising the question of in intimate symbiotic interactions with microorganisms, and these whether variation in heat sensitivity among symbionts underlies symbionts can impact thermal tolerance. When hosts are de- variation in heat sensitivity among their host species. This study pendent on symbionts that are themselves heat sensitive or cold compared aphid species with different abilities to withstand sensitive, the host’s temperature range and geographic distribution heat and showed that titers of the bacterial symbiont Buchnera drop rapidly following heat exposure of heat-sensitive aphid may be curtailed by the symbiosis. For example, the leaf-cutter ant species, whereas Buchnera titers in heat-tolerant aphid species Atta texana extends its geographic range into colder regions by are unaffected or show delayed responses. While heat-induced adopting cold-tolerant mutualistic fungi (1). Often, symbionts ap- responses of aphid hosts themselves also may contribute, sym- pear to be less heat tolerant than hosts. Thus, corals are subject to biont ability to withstand heat appears to be a central de- heat-induced elimination of their obligate algal symbionts, and if terminant of host thermal range. symbionts are killed by warming, the corals then bleach and die (2). Similarly, gut symbionts of stinkbugs are heat sensitive: Warming Author contributions: B.Z. and N.A.M. designed research; B.Z., S.P.L., and N.A.M. per- suppresses these symbionts causing stinkbug fitness to drop (3). formed research; N.A.M. contributed new reagents/analytic tools; B.Z., Y.L., and N.A.M. Many insect groups maintain obligate symbioses with maternally analyzed data; and B.Z. and N.A.M. wrote the paper. transmitted bacteria that provide essential nutrients to their hosts (4, The authors declare no competing interest. 5), raising the question of whether this dependence on heritable This article is a PNAS Direct Submission. symbionts curtails temperature tolerances and geographic ranges (6, Published under the PNAS license. 7). Heritable symbionts may be particularly heat sensitive due to Data deposition: The data reported in this paper have been deposited in National Center for Biotechnology Information, https://www.ncbi.nlm.nih.gov/ in the Nucleotide repository long-term accumulation of deleterious mutations that cause rapid (accession nos. CP042426 and CP042427) and in BioProject (ID PRJNA577642). evolution of proteins and loss of many genes (5, 8). The resulting 1To whom correspondence may be addressed. Email: [email protected]. extreme genome reduction reflects clonality and limited genetic This article contains supporting information online at www.pnas.org/lookup/suppl/doi:10. population sizes over millions of years of vertical transmission 1073/pnas.1915307116/-/DCSupplemental. within hosts (5). Among the consequences are deleterious amino www.pnas.org/cgi/doi/10.1073/pnas.1915307116 PNAS Latest Articles | 1of7 Downloaded by guest on September 26, 2021 pisum (19, 20) appears to shield hosts by buffering Buchnera fecundity: W = 51.5, P = 0.012). Ap. craccivora was also tolerant populations, possibly by producing protective metabolites (21). to heat exposure, which had no significant effects on developmental Finally, at least, in some cases, levels of Buchnera within aphids time or fecundity. In contrast, all Acyrthosiphon lines were nega- appear to decline at higher temperatures (22). tively affected. Ac. kondoi suffered both delayed maturity and re- Our central questions in this study was whether Buchnera duced fecundity (developmental time: W = 0, P < 0.001; fecundity: limits the heat tolerance of aphid hosts and whether variation W = 212.5, P < 0.001). Both lines of Ac. pisum showed delayed among aphid species in heat tolerance is linked to variation in maturity after heat shock (developmental time: 5AYC: W = 10, P < Buchnera. Aphid species vary widely in heat sensitivity (23, 24). 0.001; AusC: W = 0, P < 0.001). However, the Ac. pisum lines We documented aphid survivorship and reproduction following differed sharply in the effect of heat on fecundity. Ac. pisum AusC heat challenge in 5 widely distributed aphid species chosen on the with the heat-sensitive Buchnera ibpA genotype showed a steep drop basis of apparent differences in thermal tolerance, partly reflected in fecundity (W = 225, P < 0.001); whereas Ac. pisum 5AYC with in geographic ranges (25) (SI Appendix, Table S1). Aphis cracci- the relatively heat-tolerant Buchnera ibpA genotype showed no vora and Ap. gossypii are generalist crop pests distributed world- change in fecundity (W = 110, P = 0.933). wide in warm temperate and tropical regions, whereas Ap. fabae is a generalist that is most common in cool regions, including Effect of Heat Exposure on Buchnera Titer. To address whether the northern Europe and Canada. Ac. kondoi and Ac. pisum specialize effects of heat on hosts reflect impacts on obligate symbionts, we on alfalfa and favor cool environments. We included a second Ac. measured effects of heat exposure on the Buchnera titer in each pisum line in which Buchnera bears a single nucleotide deletion in of the aphid lines (Fig. 2 and SI Appendix, Table
Load more

Recommended publications
  • Jordan Beans RA RMO Dir
    Importation of Fresh Beans (Phaseolus vulgaris L.), Shelled or in Pods, from Jordan into the Continental United States A Qualitative, Pathway-Initiated Risk Assessment February 14, 2011 Version 2 Agency Contact: Plant Epidemiology and Risk Analysis Laboratory Center for Plant Health Science and Technology United States Department of Agriculture Animal and Plant Health Inspection Service Plant Protection and Quarantine 1730 Varsity Drive, Suite 300 Raleigh, NC 27606 Pest Risk Assessment for Beans from Jordan Executive Summary In this risk assessment we examined the risks associated with the importation of fresh beans (Phaseolus vulgaris L.), in pods (French, green, snap, and string beans) or shelled, from the Kingdom of Jordan into the continental United States. We developed a list of pests associated with beans (in any country) that occur in Jordan on any host based on scientific literature, previous commodity risk assessments, records of intercepted pests at ports-of-entry, and information from experts on bean production. This is a qualitative risk assessment, as we express estimates of risk in descriptive terms (High, Medium, and Low) rather than numerically in probabilities or frequencies. We identified seven quarantine pests likely to follow the pathway of introduction. We estimated Consequences of Introduction by assessing five elements that reflect the biology and ecology of the pests: climate-host interaction, host range, dispersal potential, economic impact, and environmental impact. We estimated Likelihood of Introduction values by considering both the quantity of the commodity imported annually and the potential for pest introduction and establishment. We summed the Consequences of Introduction and Likelihood of Introduction values to estimate overall Pest Risk Potentials, which describe risk in the absence of mitigation.
    [Show full text]
  • Iáe Comparative Host Plant Range Studies Ofthebluealfaifa
    STMSÍ^- ^ iáe Comparative Host Science and Education Administration Plant Range Studies Technical Bulletin oftheBlueAlfaifa Number 1 639 Aphiid, Acyrthosiphon Kon do/Sh in ji, and the Pea Aphid, Acyrthosiphon Pisum (l-iarris) (IHomoptera: Aphid idae) O :"-.;::>-"' C'" p _ ' ./ -• - -. -.^^ ■ ■ ■ ■ 'Zl'-'- CO ^::!:' ^. ^:"^"^ >^. 1 - «# V1--; '"^I I-*"' Í""' C30 '-' C3 ci :x: :'— -xj- -- rr- ^ T> r-^- C".' 1- 03—' O '-■:: —<' C-_- ;z: ë^GO Acknowledgments Contents Page The authors wish to thank Robert O. Kuehl and the staff Introduction -| of the Center for Quantitative Studies, University of Materials and methods -| Arizona, for their assistance in statistical analysis of Greenhouse studies -| these data. We are also grateful to S. M. Dietz, G. L Jordan, A. M. Davis, and W. H. Skrdia for providing seed Field studies 2 used in these studies. Statistical analyses 3 Resultsanddiscussion 3 Abstract Greenhouse studies 3 Field studies 5 Ellsbury, Michael M., and Nielsen, Mervin W. 1981. Classification of hosts studied in field and Comparative Host Plant Range Studies of the Blue greenhouse experiments 5 Alfalfa Aphid, Acyrthosiphon kondoi Shinji, and the Pea Conclusions Q Aphid, Acyrthosiphon pisum (Harris) (Homoptera: Literature cited 5 Aphididae). U.S. Departnnent of Agriculture, Technical Appendix 7 Bulletin No. 1639, 14 p. Host plant ranges of the blue alfalfa aphid (BAA), Acyrthosiphon kondoi Shinji, and the pea aphid (PA), Acyrthosiphon pisum (Harris), were investigated on leguminous plant species. Fecundities of BAA and PA were determined on 84 plant species from the genera Astragalus, Coronilla, Lathyrus, Lens, Lotus, Lupinus, Medicago, Melilotus, Ononis, Phaseolus, Pisum, Trifolium, Vicia, and Vigna in greenhouse studies. Both aphids displayed a broad reproductive host range extending to species in all genera tested except Phaseolus.
    [Show full text]
  • Infection Cycle of Watermelon Mosaic Virus
    Infection Cycle of Watermelon Mosaic Virus By TAKASHI YAMAMOTO* Agronomy Division, Shikoku National Agricultural Experiment Station (Senyucho, Zentsuji, Kagawa, 765 Japan) Among the viruses occurring in cucurbits transmission. As to other vectors, many of in Japan, the most prevalent ones are water­ them showed low parasitism to cucurbits and melon mosaic virus (WMV) and cucumber low ability of transmitting WMV, so that their mosaic virus (CMV) . Of them, WMV occurs role for the spread of WMV in the field was mainly in the summer season in the Kanto not clear. A survey conducted in fields of region and westward. The WMV diseases in cucurbits in 1981 spring to know the kinds of cucurbits cause not only systemic symptoms aphids which fly to the cucurbits at the initial such as mosaic, dwarf, etc. but also fruit mal­ incidence of WMV showed that more than a formation, thus giving severe damage to crops. half of the aphid species sampled were vector In addition, the control of WMV is quite dif­ species (Table 2). The initial incidence of ficult as the virus is transmitted by aphids WMV occurs usually in the period from mid­ and that carried by plant sap is also infectious. May to early-June at the survey site (west Thus, WMV is one of the greatest obstacles part of Kagawa Prefecture), and this period to the production of cucurbits. coincides with the period of abundant appear­ The infection cycle of the WMV, including ance of aphids. In this period, vector species the routes of transmission of the virus by less parasitic to cucurbits also flew in plenty aphids, which is the most important in con­ to cucurbits.
    [Show full text]
  • Aphids (Hemiptera, Aphididae)
    A peer-reviewed open-access journal BioRisk 4(1): 435–474 (2010) Aphids (Hemiptera, Aphididae). Chapter 9.2 435 doi: 10.3897/biorisk.4.57 RESEARCH ARTICLE BioRisk www.pensoftonline.net/biorisk Aphids (Hemiptera, Aphididae) Chapter 9.2 Armelle Cœur d’acier1, Nicolas Pérez Hidalgo2, Olivera Petrović-Obradović3 1 INRA, UMR CBGP (INRA / IRD / Cirad / Montpellier SupAgro), Campus International de Baillarguet, CS 30016, F-34988 Montferrier-sur-Lez, France 2 Universidad de León, Facultad de Ciencias Biológicas y Ambientales, Universidad de León, 24071 – León, Spain 3 University of Belgrade, Faculty of Agriculture, Nemanjina 6, SER-11000, Belgrade, Serbia Corresponding authors: Armelle Cœur d’acier ([email protected]), Nicolas Pérez Hidalgo (nperh@unile- on.es), Olivera Petrović-Obradović ([email protected]) Academic editor: David Roy | Received 1 March 2010 | Accepted 24 May 2010 | Published 6 July 2010 Citation: Cœur d’acier A (2010) Aphids (Hemiptera, Aphididae). Chapter 9.2. In: Roques A et al. (Eds) Alien terrestrial arthropods of Europe. BioRisk 4(1): 435–474. doi: 10.3897/biorisk.4.57 Abstract Our study aimed at providing a comprehensive list of Aphididae alien to Europe. A total of 98 species originating from other continents have established so far in Europe, to which we add 4 cosmopolitan spe- cies of uncertain origin (cryptogenic). Th e 102 alien species of Aphididae established in Europe belong to 12 diff erent subfamilies, fi ve of them contributing by more than 5 species to the alien fauna. Most alien aphids originate from temperate regions of the world. Th ere was no signifi cant variation in the geographic origin of the alien aphids over time.
    [Show full text]
  • Comparative Host Plant Range Studies of the Blue Alfalfa Aphid, Acyrthosiphon Kondoi Shinji, and the Pea Aphid, Acyrthosiphon Pisum (Harris) (Homoptera: Aphididae)
    t ... !' -, ~12,8 ~~2.5 ~W '1 2,5 W ~ 1.0 W w I~ 2.2 wlji w 11111 w 2.2 &.:: I~ &.::~ a:. a:. ~ ~ ::t ~ ... M 1.1 ..".. /1.1 .."... ..M I 4 '''''1.25/1'''1.4 111111.6 1111,1.25"",1. 111111.6 MICROCOPY RESOLUTION TEST CHART MICROCOPY RESOLUTION TEST CHART NATIONAL BUREAU or ST ANDARDS-1963-A NATIONAL BUREAU or :;iANDARDS-1963-A ~~\ United States {~ Department of ~ Agriculture Comparative Host Science and Education Adm in istration Plant Range Studies Technical B:.Jlletln of the Blue Alfalfa Number 1639 Aphid, Acyrthosiphon Kondoi Shinji, and the Pea Aphid, Acyrthosiphon Pisum (Harris) ( Homoptera: Aphididae) Acknowledgments Contents Page The authors wish to thank Robert O. Kuehl and the staff Introduction ___________________________________ 1 of the Center for Quantitative Studies, University of Materials and methods __________________________ 1 Arizona, for their assistance in statistical analysis of Greenhousestudies___________________________ 1 these data. We are also grateful to S. M. Dietz, G. L. Field studies _________________________________ 2 Jordan. A. M. Davis, and W. H. Skrdla for providing seed Statistical analyses ___________________________ 3 used in these studies. Results and discussion __________________________ 3 Greenhouse studies____________ ._______________ 3 Abstract Field studies_________________________________ 5 Ellsbury. Michael M., and Nielson. Mervin W. 1981. Classification of hosts studied in field and Comparative Host Plant Range Studies of the Blue greenhouse experi ments_____________________ 5 Aifalfa Aphid. Acyrthosiphon kondoi Shinji. and the Pea Conclusions ___________________________________ 6 Aphid. Acyrthosiphon pisum (Harris) (Homoptera: Literature cited_________________________________ 6 Aphididae). U.S. Department of Agriculture, Technical Appendix________________________________ ------ 7 Bulletin No. 1639. 14 p. Host plant ranges of the b!~le alfalfa aphid (BAA), Acyrthosiphon kondoi Sh;11ji, and the pea aphid (PA), Acyrthosiphon pisum (Harris), were investigated on leguminous plant species.
    [Show full text]
  • Aphid Transmission of Potyvirus: the Largest Plant-Infecting RNA Virus Genus
    Supplementary Aphid Transmission of Potyvirus: The Largest Plant-Infecting RNA Virus Genus Kiran R. Gadhave 1,2,*,†, Saurabh Gautam 3,†, David A. Rasmussen 2 and Rajagopalbabu Srinivasan 3 1 Department of Plant Pathology and Microbiology, University of California, Riverside, CA 92521, USA 2 Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, NC 27606, USA; [email protected] 3 Department of Entomology, University of Georgia, 1109 Experiment Street, Griffin, GA 30223, USA; [email protected] * Correspondence: [email protected]. † Authors contributed equally. Received: 13 May 2020; Accepted: 15 July 2020; Published: date Abstract: Potyviruses are the largest group of plant infecting RNA viruses that cause significant losses in a wide range of crops across the globe. The majority of viruses in the genus Potyvirus are transmitted by aphids in a non-persistent, non-circulative manner and have been extensively studied vis-à-vis their structure, taxonomy, evolution, diagnosis, transmission and molecular interactions with hosts. This comprehensive review exclusively discusses potyviruses and their transmission by aphid vectors, specifically in the light of several virus, aphid and plant factors, and how their interplay influences potyviral binding in aphids, aphid behavior and fitness, host plant biochemistry, virus epidemics, and transmission bottlenecks. We present the heatmap of the global distribution of potyvirus species, variation in the potyviral coat protein gene, and top aphid vectors of potyviruses. Lastly, we examine how the fundamental understanding of these multi-partite interactions through multi-omics approaches is already contributing to, and can have future implications for, devising effective and sustainable management strategies against aphid- transmitted potyviruses to global agriculture.
    [Show full text]
  • Eco-Climatic Assessment of the Potential Establishment of Exotic Insects in New Zealand
    Eco-climatic assessment of the potential establishment of exotic insects in New Zealand A thesis submitted in partial fulfillment of the requirements for the Degree of Doctor of Philosophy at Lincoln University by Lora Peacock Lincoln University 2005 Contents Abstract of a thesis submitted in partial fulfillment of the requirements for the Degree of PhD Eco-climatic assessment of the potential establishment of exotic insects in New Zealand Lora Peacock To refine our knowledge and to adequately test hypotheses concerning theoretical and applied aspects of invasion biology, successful and unsuccessful invaders should be compared. This study investigated insect establishment patterns by comparing the climatic preferences and biological attributes of two groups of polyphagous insect species that are constantly intercepted at New Zealand's border. One group of species is established in New Zealand (n = 15), the other group comprised species that are not established (n = 21). In the present study the two groups were considered to represent successful and unsuccessful invaders. To provide background for interpretation of results of the comparative analysis, global areas that are climatically analogous to sites in New Zealand were identified by an eco­ climatic assessment model, CLIMEX, to determine possible sources of insect pest invasion. It was found that south east Australia is one of the regions that are climatically very similar to New Zealand. Furthermore, New Zealand shares 90% of its insect pest species with that region. South east Australia has close trade and tourism links with New Zealand and because of its proximity a new incursion in that analogous climate should alert biosecurity authorities in New Zealand.
    [Show full text]
  • Aphids (Hemiptera, Aphididae) Armelle Coeur D’Acier, Nicolas Pérez Hidalgo, Olivera Petrovic-Obradovic
    Aphids (Hemiptera, Aphididae) Armelle Coeur d’Acier, Nicolas Pérez Hidalgo, Olivera Petrovic-Obradovic To cite this version: Armelle Coeur d’Acier, Nicolas Pérez Hidalgo, Olivera Petrovic-Obradovic. Aphids (Hemiptera, Aphi- didae). Alien terrestrial arthropods of Europe, 4, Pensoft Publishers, 2010, BioRisk, 978-954-642-554- 6. 10.3897/biorisk.4.57. hal-02824285 HAL Id: hal-02824285 https://hal.inrae.fr/hal-02824285 Submitted on 6 Jun 2020 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. A peer-reviewed open-access journal BioRisk 4(1): 435–474 (2010) Aphids (Hemiptera, Aphididae). Chapter 9.2 435 doi: 10.3897/biorisk.4.57 RESEARCH ARTICLE BioRisk www.pensoftonline.net/biorisk Aphids (Hemiptera, Aphididae) Chapter 9.2 Armelle Cœur d’acier1, Nicolas Pérez Hidalgo2, Olivera Petrović-Obradović3 1 INRA, UMR CBGP (INRA / IRD / Cirad / Montpellier SupAgro), Campus International de Baillarguet, CS 30016, F-34988 Montferrier-sur-Lez, France 2 Universidad de León, Facultad de Ciencias Biológicas y Ambientales, Universidad de León, 24071 – León, Spain 3 University of Belgrade, Faculty of Agriculture, Nemanjina 6, SER-11000, Belgrade, Serbia Corresponding authors: Armelle Cœur d’acier ([email protected]), Nicolas Pérez Hidalgo (nperh@unile- on.es), Olivera Petrović-Obradović ([email protected]) Academic editor: David Roy | Received 1 March 2010 | Accepted 24 May 2010 | Published 6 July 2010 Citation: Cœur d’acier A (2010) Aphids (Hemiptera, Aphididae).
    [Show full text]
  • Seasonal Abundance of Acyrthosiphon Pisum (Harris) (Homoptera: Aphididae) and Therioaphis Trifola (Monell) (Homoptera: Callaphididae) on Lucerne in Central Greece1
    ENTOMOLOGIA ÌIELLENICA 8 ( 1990): 41-46 Seasonal Abundance of Acyrthosiphon pisum (Harris) (Homoptera: Aphididae) and Therioaphis trifola (Monell) (Homoptera: Callaphididae) on Lucerne in Central Greece1 D. P. LYKOURESSIS and CH. P. POLATSIDIS Laboratory of Agricultural Zoology and Entomology, Agricultural University of Athens, 75 lera Odos, GR 118 55 Athens, Greece ABSTRACT Acyrthosiphonpisum (Harris) and Therioaphis trifolii (Monell) were the most abun­ dant aphid species on lucerne at Kopais, Co. Boiotia in central Greece from April 1984 to November 1986. Population fluctuations for A. pisum showed two peaks, the first during April-May and the second in November. Low numbers or zero were found during summer and till mid October as well as during winter and March. The abundance of this species during the year agrees generally with the effects of pre­ vailing temperatures in the region on aphid development and reproduction. T. tri­ fola also showed two population peaks but at different periods. The first occurred in July and the second from mid September to mid October. The first peak was higher than the second. The sharp decline in population densities that occurred in early August and lasted till mid September is not accounted for by adverse climatic conditions, but natural enemies and/or other limiting factors are possibly respon­ sible for that population reduction. Numbers were zero from December till March. while they kept at low levels during the rest of spring and part of June as well as from mid October till the end of November. Introduction species occurring quite frequently on lucerne in Several aphid species are known to attack temperate regions.
    [Show full text]
  • Alfalfa Insects II EXTENSION UNL Department of Entomology EXTENSION Robert J
    Alfalfa Insects II EXTENSION UNL Department of Entomology EXTENSION Robert J. Wright, Terry A. DeVries, and Jim A. Kalisch EC1577 1. Pea Aphid 2. Spotted Alfalfa Aphid 3. Cowpea Aphid 4. Blue Alfalfa Aphid Nymph Adult 5. Potato Leafhopper 6. Plant Bug © 2009, The Board of Regents of the University of Nebraska. All rights reserved. Insects Identification Pea Aphid Adult: Light green to yellow-green, largest aphid species found in alfalfa with long legs and an- Acyrthosiphon pisum (Harris) tenna, up to ¼ inch long. Antennae have narrow dark bands at the end of each segment. A pink to red variant has also been reported. Populations occur during the summer and decline when daytime temperatures reach 85º-90º F. Damage appears as leaf yellowing and plant stunting. High population densities may cause wilting and plant death. 1 1 Spotted Alfalfa Aphid Adult: Light tan with six rows of dark spots along the back of the body, about /16 to /8 inch long. This Therioaphis maculata (Buckton) aphid species has the greatest potential to cause loss of alfalfa stands. During the summer and fall, this warm season aphid species can reproduce and increase population levels even when daytime temperatures exceed 85º-90º F. Populations occur in greatest number on leaves and stems in the lower portion of the plant canopy, near the soil surface. Feeding causes a toxic reaction in alfalfa which results in chlorosis, leaf drop, and plant death when high population levels are present. Vein- banding in newly formed leaves emerging from plant terminals is a distinctive symptom of damage.
    [Show full text]
  • Strategies for Aphid Management in Alfalfa
    STRATEGIES FOR APHID MANAGEMENT IN ALFALFA Ayman M. Mostafa1 INTRODUCTION Alfalfa is an important commodity for dairy and livestock enterprises and is the first in terms of acreage planted in Arizona and second to almond in California. It dominates the cropping systems in the Western US given the importance of the dairy industry and other livestock enterprises. Alfalfa is considered the insectary of the west; providing refuge to wildlife and a variety of beneficial insects, improves soil characteristics, contributes to atmospheric nitrogen fixation through rhizobacteria, traps sediments and takes up nitrate pollutants, mitigates water and air pollution, and provides appealing and pleasing open landscape. Alfalfa also plays an important role in insecticide resistance management by acting as a refuge for susceptible genotypes; e.g., the sweetpotato whitefly Bemisia tabaci Gennadius. Beneficial insects move from alfalfa fields into other crops, where they play crucial roles in pollination and biological control. Broad- spectrum insecticides use in alfalfa affect beneficial insect populations and causes potential long- term effects across the entire landscape. A complex of four alfalfa aphids in the region, pea aphid (PA) Acyrthosiphon pisum (Harris), the blue alfalfa aphid (BAA) Acyrthosiphon kondoi L., the spotted alfalfa aphid (SAA), Therioaphis maculatato (Buckton), and the cowpea aphid, (CPA), Aphis craccivora C.L. Koch. The first two aphids are the most common and dangerous in the southwest desert of the U.S. The Aphid populations are highest in the winter and spring months when the first cuttings of the year occurred. These first cuttings are in high demand for the dairy industry. The spotted alfalfa aphid was the first and most devastating alfalfa aphid outbreak on record in 1954.
    [Show full text]
  • Developing and Communicating Strategies for Controlling Virus Diseases in Vegetable Cucurbit Crops
    Developing and communicating strategies for controlling virus diseases in vegetable cucurbit crops Brenda Coutts Department of Agriculture & Food Western Australia Project Number: VG06022 VG06022 This report is published by Horticulture Australia Ltd to pass on information concerning horticultural research and development undertaken for the vegetables industry. The research contained in this report was funded by Horticulture Australia Ltd with the financial support of the vegetables industry. All expressions of opinion are not to be regarded as expressing the opinion of Horticulture Australia Ltd or any authority of the Australian Government. The Company and the Australian Government accept no responsibility for any of the opinions or the accuracy of the information contained in this report and readers should rely upon their own enquiries in making decisions concerning their own interests. ISBN 0 7341 2866 5 Published and distributed by: Horticulture Australia Ltd Level 7 179 Elizabeth Street Sydney NSW 2000 Telephone: (02) 8295 2300 Fax: (02) 8295 2399 © Copyright 2012 FINAL REPORT HORTICULTURE AUSTRALIA PROJECT VG06022 Developing and communicating strategies for controlling virus diseases in vegetable cucurbit crops Brenda Coutts, et al . Department of Agriculture and Food, Western Australia June 2011 HORTICULTURE AUSTRALIA LIMITED PROJECT VG06022 Project leader Ms Brenda Coutts Plant Virologist Department of Agriculture and Food 3 Baron-Hay Court, South Perth Western Australia, 6151 [email protected] (08) 93268 3266 This is the final report for the project VGO6022 ‘Developing and communicating strategies for controlling virus diseases in vegetable cucurbit crops’. June 2011 This project was aimed at developing and communicating strategies for controlling virus diseases in vegetable cucurbit crops in Australia.
    [Show full text]