DOCSLIB.ORG

Signatures of Host/Symbiont Genome Coevolution in Insect Nutritional

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Signatures of Host/Symbiont Genome Coevolution in Insect Nutritional PAPER Signatures of host/symbiont genome coevolution in COLLOQUIUM insect nutritional endosymbioses Alex C. C. Wilson1 and Rebecca P. Duncan Department of Biology, University of Miami, Coral Gables, FL 33146 Edited by John P. McCutcheon, University of Montana, Missoula, MT, and accepted by the Editorial Board May 5, 2015 (received for review February 2, 2015) The role of symbiosis in bacterial symbiont genome evolution is these ancient, intimate symbiotic associations. Our purpose here well understood, yet the ways that symbiosis shapes host genomes is to highlight three signatures of genome coevolution across or more particularly, host/symbiont genome coevolution in the available holobiont genomes and to draw attention to work at holobiont is only now being revealed. Here, we identify three the frontier of symbiosis research that elucidates mechanisms of coevolutionary signatures that characterize holobiont genomes. The holobiont regulation and integration. first signature, host/symbiont collaboration, arises when completion of essential pathways requires host/endosymbiont genome com- Three Signatures: Collaboration, Acquisition, and Constraint plementarity. Metabolic collaboration has evolved numerous times Holobiont genome evolution is characterized by patterns of col- in the pathways of amino acid and vitamin biosynthesis. Here, we laboration, acquisition, and constraint. Coevolution typically fea- highlight collaboration in branched-chain amino acid and pantothe- tures host/endosymbiont collaboration on completion of critical nate (vitamin B5) biosynthesis. The second coevolutionary signature metabolic pathways—a set of pathways that is similar across taxa, is acquisition, referring to the observation that holobiont genomes apparently constrained by eukaryotic host gene repertoire and yet, acquire novel genetic material through various means, including concurrently, holobiont genome evolution is dynamic. Dynamic gene duplication, lateral gene transfer from bacteria that are not features include acquisition of novel genomic material like du- their current obligate symbionts, and full or partial endosymbiont plicate genes, genes acquired by lateral gene transfer that enhance replacement. The third signature, constraint, introduces the idea collaboration, and acquisition of coprimary symbionts or even new that holobiont genome evolution is constrained by the processes primary symbionts by symbiont replacement. EVOLUTION governing symbiont genome evolution. In addition, we propose that collaboration is constrained by the expression profile of the Collaboration cell lineage from which endosymbiont-containing host cells, called Long before it was possible to elucidate the metabolic repertoire bacteriocytes, are derived. In particular, we propose that such of an organism by sequencing its DNA, researchers established differences in bacteriocyte cell lineage may explain differences in the metabolic basis of many insect nutritional symbioses experi- patterns of host/endosymbiont metabolic collaboration between mentally by quantifying the growth and fecundity of insects ma- the sap-feeding suborders Sternorrhyncha and Auchenorrhynca. nipulated in a diversity of ways that included some combination of Finally, we review recent studies at the frontier of symbiosis research endosymbiont removal and diet manipulations (13). Such analyses that are applying functional genomic approaches to characterization established that endosymbionts provision host insects with dietary of the developmental and cellular mechanisms of host/endosymbiont components lacking or at low availability in their diets. Thus, at integration, work that heralds a new era in symbiosis research. the beginning of the genomic revolution it was understood that hosts supply endosymbionts with metabolic precursors that en- symbiosis | insect nutritional | coevolution | amino acid biosynthesis | dosymbionts metabolically transform into host-required dietary vitamin biosynthesis components. Notably, from an organismal perspective, insect nu- tritional symbioses in pregenome times were partnerships between any insects have established persistent, intimate associa- two discrete organisms: the host and the endosymbiont. Endo- Mtions with vertically transmitted microbial symbionts. These symbiont whole-genome sequencing affirmed and continues to ancient, commonly intracellular symbionts are, owing to their affirm the nutritional role played by symbionts, whereas host greatly reduced, gene-poor genomes, uncultivable outside their genome and transcriptome sequencing reveals a complex por- hosts. Although the whole-genome sequences of obligate insect trait of the nature and extent of host/endosymbiont metabolic endosymbionts continue to yield novel insight into genome evo- complementarity. lution following adoption of an obligate intracellular lifestyle (e.g., Currently the most well-documented examples of host/endo- ref. 1), it is the recent partnering of these symbiont genome se- symbiont metabolic collaboration involve the biosynthesis of quences with those of their insect hosts that fundamentally shifts essential amino acids in plant sap-feeding insects (2, 7–9, 14–16). conceptualization of “the organism,” propelling us into a new era In most cases, holobiont metabolism has been reconstructed in symbiosis research. using the whole-genome sequence of the symbiont coupled with The first paired insect host/endosymbiont genome available a host bacteriome transcriptome (the bacteriome is the host was that of the pea aphid, Acyrthosiphon pisum and its bacterial endosymbiont, Buchnera aphidicola (2, 3). The second was that of the human body louse, Pediculus humanus humanus and its This paper results from the Arthur M. Sackler Colloquium of the National Academy of primary bacterial endosymbiont Candidatus Riesia pediculicola Sciences, “Symbioses Becoming Permanent: The Origins and Evolutionary Trajectories of (4), quickly followed by the carpenter ant, Camponotus floridanus Organelles,” held October 15–17, 2014, at the Arnold and Mabel Beckman Center of the National Academies of Sciences and Engineering in Irvine, CA. The complete program (5) and its endosymbiont Candidatus Blochmannia floridanus (6). and video recordings of most presentations are available on the NAS website at www. Other insect holobiont genomes now include the citrus mealybug, nasonline.org/Symbioses. Planococcus citri with its dual endosymbionts (7, 8); the hackberry Author contributions: A.C.C.W. and R.P.D. designed research, performed research, ana- petiole gall psyllid Pachypsylla venusta with its endosymbiont lyzed data, and wrote the paper. Candidatus Carsonella ruddii (9); and the tsetse fly, Glossina The authors declare no conflict of interest. morsitans (10) with its endosymbiont Wigglesworthia glossinidia This article is a PNAS Direct Submission. J.P.M. is a guest editor invited by the Editorial (11, 12). This recent accumulation of holobiont genomes facili- Board. tates elucidation of the patterns that characterize coevolution in 1To whom correspondence should be addressed. Email: [email protected]. www.pnas.org/cgi/doi/10.1073/pnas.1423305112 PNAS | August 18, 2015 | vol. 112 | no. 33 | 10255–10261 Downloaded by guest on September 28, 2021 symbiosomal membrane bacteriocyte cell membrane Symbiont with host Bacteriocyte Bacteriome Host insect symbiosomal membrane with symbionts with bacteriocytes with bacteriome Fig. 1. Organization of endosymbionts in insect hosts. Typically enveloped by a host membrane (green) within the cytoplasm of specialized host bacteriocyte cells, insect nutritional endosymbionts (purple) are maternally transmitted and integrated into host development by currently unknown mechanisms. In- dividual bacteriocyte cells house thousands to tens of thousands of symbionts. Many bacteriocyte cells aggregate to form an organ called the bacteriome. Bacteriomes are typically paired and relatively large. organ composed of host bacteriocyte cells that house the en- encoding pantothenate synthetase (E.C. 6.3.2.1) that functions dosymbionts) (Fig. 1) and a partial host genome. In the case of only in pantothenate biosynthesis (Fig. 2) (18). Thus, we venture the pea aphid, metabolic reconstruction leveraged the com- that examination of the host genomes and transcriptomes of plete genome of both symbiont and host (2, 14). The many these four endosymbionts will demonstrate that pantothenate similarities and differences in the collaborative amino acid bio- biosynthesis is indeed functional in these holobionts as a result of synthesis of plant sap-feeding holobionts have recently been host/endosymbiont metabolic collaboration. reviewed by Sloan et al. (9) and Hansen and Moran (17). It is clear that metabolic collaboration is a fundamental sig- Therefore, here we illustrate the collaborative signature of host/ nature of host/symbiont genome coevolution. However, the ex- symbiont genome coevolution by drawing attention to one set of tent to which patterns of metabolic collaboration in holobionts amino acid biosynthesis pathways, those for biosynthesis of the result from convergence and not shared ancestry remains to be branched-chain amino acids. Biosynthesis of the branched-chain determined. Distinguishing between traits shared by conver- amino acids, isoleucine, leucine, and valine, involves host/endo- gence and those shared by common ancestry requires charac- symbiont metabolic collaboration in both A. pisum (14, 15, 16) and ter state information for a broad range of closely related taxa
Load more

Recommended publications
  • Soybean Mosaic Virus
    -- CALIFORNIA D EP AUM ENT OF cdfa FOOD & AGRICULTURE ~ California Pest Rating Proposal for Soybean mosaic virus Current Pest Rating: none Proposed Pest Rating: C Kingdom: Orthornavirae; Phylum: Pisuviricota Class: Stelpaviricetes; Order: Patatavirales Family: Potyviridae; Genus: Potyvirus Comment Period: 6/15/2020 through 7/30/2020 Initiating Event: On August 9, 2019, USDA-APHIS published a list of “Native and Naturalized Plant Pests Permitted by Regulation”. Interstate movement of these plant pests is no longer federally regulated within the 48 contiguous United States. There are 49 plant pathogens (bacteria, fungi, viruses, and nematodes) on this list. California may choose to continue to regulate movement of some or all these pathogens into and within the state. In order to assess the needs and potential requirements to issue a state permit, a formal risk analysis for Soybean mosaic virus is given herein and a permanent pest rating is proposed. History & Status: Background: The family Potyviridae contains six genera and members are notable for forming cylindrical inclusion bodies in infected cells that can be seen with light microscopy. Of the six genera, the genus Potyvirus contains by far the highest number of important plant pathogens Named after Potato virus Y, “pot-y-virus” particles are flexuous and filamentous and composed of ssRNA and a protein coat. Most diseases caused by potyviruses appear primarily as mosaics, mottling, chlorotic rings, or color break on foliage, flowers, fruits, and stems. Many cause severe stunting of young plants and drastically reduced yields with leaf, fruit, and stem malformations, fruit drop, and necrosis (Agrios, 2005). Soybean is one of the most important sources of edible oil and proteins for people and animals, and a source of biofuel.
    [Show full text]
  • Arthropods of Elm Fork Preserve
    Arthropods of Elm Fork Preserve Arthropods are characterized by having jointed limbs and exoskeletons. They include a diverse assortment of creatures: Insects, spiders, crustaceans (crayfish, crabs, pill bugs), centipedes and millipedes among others. Column Headings Scientific Name: The phenomenal diversity of arthropods, creates numerous difficulties in the determination of species. Positive identification is often achieved only by specialists using obscure monographs to ‘key out’ a species by examining microscopic differences in anatomy. For our purposes in this survey of the fauna, classification at a lower level of resolution still yields valuable information. For instance, knowing that ant lions belong to the Family, Myrmeleontidae, allows us to quickly look them up on the Internet and be confident we are not being fooled by a common name that may also apply to some other, unrelated something. With the Family name firmly in hand, we may explore the natural history of ant lions without needing to know exactly which species we are viewing. In some instances identification is only readily available at an even higher ranking such as Class. Millipedes are in the Class Diplopoda. There are many Orders (O) of millipedes and they are not easily differentiated so this entry is best left at the rank of Class. A great deal of taxonomic reorganization has been occurring lately with advances in DNA analysis pointing out underlying connections and differences that were previously unrealized. For this reason, all other rankings aside from Family, Genus and Species have been omitted from the interior of the tables since many of these ranks are in a state of flux.
    [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]
  • Taxonomy Geographical Distribution
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Beiträge zur Entomologie = Contributions to Entomology... Beitr. Ent., Berlin 25 (1975) 2, S. 2 57 -2 6 0 W i l h e l m PiECK-Universität R ostock Sektion Biologie Eorschungsgruppe Phyto-Entomologie Rostock F r i t z P a u l M u l l e r Incidence of the aphid Acyrthosiphon gossypii M o r d v i l k o on legumes and on cotton (Homoptera: Aphididae) With 2 text figures Some recently published papers have shown the aphid Acyrthosiphon sesbaniae K a s a - k a r a j D a v i d to he an efficacious vector for viruses of cultivated Fabaceae. K a i s e r & S o h a l k (1973) carried out transmission experiments with the circulative pea leaf roll virus which can cause serious losses in food legume crops in Iran and obtained high trans­ mission rates with A. sesbaniae. In the Northern Province of the Sudan A b ij S a l i h et al. (1973) ascertained the efficient transmissibility of the Sudanese broad bean mosaic virus by A. sesbaniae on Vida faba. The book of S chmtjtterer (1963) relates A. sesbaniae as an effective vector of the pea mosaic virus in central Sudan. During a visit in the Hudeiha Research Station in the Northern Province of the Sudan the present author found Vicia faba crops heavily infested by A. sesbaniae. Despite of the considerable virus transmitting ability and the mass infestation of particularly suitable host plants there exists no survey on the biology, host range and geographical distribution of the aphid.
    [Show full text]
  • An Updated Classification of the Jumping Plant-Lice (Hemiptera
    European Journal of Taxonomy 736: 137–182 ISSN 2118-9773 https://doi.org/10.5852/ejt.2021.736.1257 www.europeanjournaloftaxonomy.eu 2021 · Burckhardt D. et al. This work is licensed under a Creative Commons Attribution License (CC BY 4.0). Research article urn:lsid:zoobank.org:pub:F2976039-934E-46BE-B839-4D28C92C871F An updated classifi cation of the jumping plant-lice (Hemiptera: Psylloidea) integrating molecular and morphological evidence Daniel BURCKHARDT 1,*, David OUVRARD 2 & Diana M. PERCY 3 1 Naturhistorisches Museum, Augustinergasse 2, 4001 Basel, Switzerland. 2 ANSES, Plant Health Laboratory, Entomology and invasive plants unit, 755 avenue du campus Agropolis, CS 30016, 34988 Montferrier-sur-Lez Cedex, France. 3 Department of Botany, University of British Columbia, 6270 University Boulevard, Vancouver V6T 1Z4, Canada. * Corresponding author: [email protected] 2 Email: [email protected] 3 Email: [email protected] 1 urn:lsid:zoobank.org:author:2FA5C7E5-D28E-4220-9796-02717E892B1D 2 urn:lsid:zoobank.org:author:2748132A-5D53-4BBA-9E33-F2723DCAAF19 3 urn:lsid:zoobank.org:author:84F3C908-9927-40A6-BBBF-6951B7736278 Abstract. The classifi cation of the superfamily Psylloidea is revised to incorporate fi ndings from recent molecular studies, and to integrate a reassessment of monophyla primarily based on molecular data with morphological evidence and previous classifi cations. We incorporate a reinterpretation of relevant morphology in the light of the molecular fi ndings and discuss confl icts with respect to different data sources and sampling strategies. Seven families are recognised of which four (Calophyidae, Carsidaridae, Mastigimatidae and Triozidae) are strongly supported, and three (Aphalaridae, Liviidae and Psyllidae) weakly or moderately supported.
    [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]
  • Parasitoids Induce Production of the Dispersal Morph of the Pea Aphid, Acyrthosiphon Pisum
    OIKOS 98: 323–333, 2002 Parasitoids induce production of the dispersal morph of the pea aphid, Acyrthosiphon pisum John J. Sloggett and Wolfgang W. Weisser Sloggett, J. J. and Weisser, W. W. 2002. Parasitoids induce production of the dispersal morph of the pea aphid, Acyrthosiphon pisum. – Oikos 98: 323–333. In animals, inducible morphological defences against natural enemies mostly involve structures that are protective or make the individual invulnerable to future attack. In the majority of such examples, predators are the selecting agent while examples involving parasites are much less common. Aphids produce a winged dispersal morph under adverse conditions, such as crowding or poor plant quality. It has recently been demonstrated that pea aphids, Acyrthosiphon pisum, also produce winged offspring when exposed to predatory ladybirds, the first example of an enemy-in- duced morphological change facilitating dispersal. We examined the response of A. pisum to another important natural enemy, the parasitoid Aphidius er6i, in two sets of experiments. In the first set of experiments, two aphid clones both produced the highest proportion of winged offspring when exposed as colonies on plants to parasitoid females. In all cases, aphids exposed to male parasitoids produced a higher mean proportion of winged offspring than controls, but not significantly so. Aphid disturbance by parasitoids was greatest in female treatments, much less in male treatments and least in controls, tending to match the pattern of winged offspring production. In a second set of experiments, directly parasitised aphids produced no greater proportion of winged offspring than unparasitised controls, thus being parasitised itself is not used by aphids for induction of the winged morph.
    [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]
  • Proposal to Sequence the Genome of the Pea Aphid (Acyrthosiphon Pisum)
    Proposal To Sequence the Genome of the Pea Aphid (Acyrthosiphon pisum) The International Aphid Genomics Consortium (IAGC) Steering Committee (in alphabetical order): Marina Caillauda, Owain Edwardsb, Linda Fieldc, Danièle Giblot- Ducrayd, Stewart Graye, David Hawthornef, Wayne Hunterg, Georg Janderh, Nancy Morani, Andres Moyaj, Atsushi Nakabachik, Hugh Robertsonl, Kevin Shufranm, Jean- Christophe Simond, David Sternn, Denis Tagud Contact: D. Stern; Ph. 609-258-0759; FAX 609-258-7892; [email protected] Abstract We propose sequencing of the 300Mb nuclear genome of the pea aphid, Acyrthosiphon pisum. Aphids display a diversity of biological problems that are not easily studied in other genetic model systems. First, because they are the premier model for the study of bacterial endosymbiosis and because they vector many well-studied plant viruses, aphids are an excellent model for studying animal interactions with microbes. Second, because their normal life cycle displays extreme developmental plasticity as well as both clonal and sexual reproduction, aphids provide the opportunity to understand the basis of phenotypic plasticity as well as the genomic consequences of sexual versus asexual reproduction. Their alternative reproductive modes can also be exploited in genetic experiments, because clones can be maintained indefinitely in the laboratory with sexual generations induced at will1,2. Third, aphids provide some of the best studied instances of adaptation, in the form of both insecticide resistance, which has evolved through several molecular mechanisms, and host plant adaptation, which has repeatedly generated novel aphid lineages specialized to particular crop plant cultivars and which is presumably the basis for the radiation of aphids onto many specialized host plants during their long evolutionary history.
    [Show full text]
  • ABSTRACT Biosystematics and the Evolution of Gall
    ABSTRACT Title of Dissertation: Biosystematics and the evolution of gall formation in hackberry psyllids Pachypsylla (Insecta: Homoptera: Psylloidea: Psyllidae) Man-Miao Yang, Doctor of Philosophy, 1995 Dissertation directed by Charles Mitter, Associate Professor, Maryland Center for Systematic Entomology, Department of Entomology; and Douglass R. Miller, Research Entomologist, Systematic Entomology Laboratory, Beltsville Agricultural Research Center, USDA This dissertation is a study of the phylogeny and evolutionary biology of gall formation in psyllids of the subfamily Sponclyliaspiclinae, with particular focus on North American hackberry gallers in the genus Pachypsylla. Species in this genus produce a variety of gall types on the leaves, petioles, buds and twigs of their hosts, four species of Celt is subgen. Euceltis (Ulmaceae ). The homogeneity of adult morphology in Pachyp.sylla, contrasted to the great variation in gall morphology and phenology, has led to much difficulty in delimiting species. Chapter I investigates species limits as related to gall type and host specificity in Pachypsylla. Strong differences in allozymes, morphology and life history confirm that leaf, petiole, bud and twig gallers belong to different species or species groups. Different leaf gall morphs probably also represent different species, as evidenced by significant all ozyme freque ncy diffe rences among sympatric pairs of gall morphs, consistent frequency difference between co- occurring morphs across localities, and discrete differences in gall type between progenies of individual females. Differences in allozymes, female phenology, adult and nymphal coloration, as well as laboratory rearings and field manipulations, show that side cell individuals within two nipple gall types represent an inquiline sibling species (Chapter II). Chapter III is an analysis of phylogenetic relationships within Pachypsylla, based on allozyme, morphological, life history and chromosome characters.
    [Show full text]
  • Morphogenesis of Galls Induced by Baccharopelma Dracunculifoliae (Hemiptera: PSYLLIDAE) on Baccharis Dracunculifolia (Asteraceae) Leaves
    MORPHOGENESIS OF GALLS INDUCED BY Baccharopelma dracunculifoliae (HEMIPTERA: PSYLLIDAE) ON Baccharis dracunculifolia (ASTERACEAE) LEAVES ARDUIN, M.1, FERNANDES, G. W.2 and KRAUS, J. E.3 1Department of Botany, Federal University of São Carlos, C.P. 676, CEP 13565-905, São Carlos, SP, Brazil 2Department of General Biology, Institute of Biological Sciences, Federal University of Minas Gerais, C.P. 486, CEP 30161-970, Belo Horizonte, MG, Brazil 3Institute of Biosciences, University of São Paulo, USP, C.P. 11461, CEP 05508-900, São Paulo, SP, Brazil Correspondence to: Marcos Arduin, Department of Botany, Federal University of São Carlos, C.P. 676, CEP 13565-905, São Carlos, SP, Brazil, e-mail: [email protected] Received February 2, 2004 – Accepted March 31, 2004 – Distributed November 30, 2005 (With 33 figures) ABSTRACT The commonest insect gall on Baccharis dracunculifolia (Asteraceae) leaves is induced by Baccharopelma dracunculifoliae (Hemiptera, Psyllidae). The gall-inducing insect attacks young leaves in both the unfolded and the fully expanded stages. Four developmental phases were observed in this type of gall: 1) A folding phase, during which the leaf lamina folded upward alongside the midrib and the edges of the upper portion of the leaf approached each other, forming a longitudinal slit. A single chamber was formed on the adaxial surface of the leaf; 2) A swelling phase, in which the folded leaf tissues thickened and the edges of the leaf drew closer together, narrowing the slit. In this phase the gall matured, turning succulent, fusiform and pale green. The single nymphal chamber was lined with white wax and was able to house from one to several nymphs; 3) A dehiscence phase, characterized by the opening of the slit to release inducers; and 4) A senescence phase, when the gall turned dark and dry.
    [Show full text]
  • Experimental Pathogenicity of Erwinia Aphidicola to Pea Aphid, a Cyrthosiphon Pisum
    J. Gen. App!. Microbiol., 43, 363-367 (1997) Experimental pathogenicity of Erwinia aphidicola to pea aphid, A cyrthosiphon pisum Hosami Harada*,t and Hajime Ishikawa Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo 113, Japan (Received October 17, 1997; Accepted December 11,1997) Pea aphids were reared aseptically in the laboratory and fed on strains of Erwinia aphidicola, Er- winia herbicola, Klebsiella pneumoniae, Escherichia coil and bacterium W, an aphid enterobac- terium, by mixing with a synthetic diet to determine whether these bacteria have pathogenicity to the insect. It turned out that Er. aphidicola and Er. herbicola grew in aphid gut, while K. pneumo- niae, Es. coil and bacterium W were effectively eliminated. In the case of Er. aphidicola, ingestion of a single dose of 103 CFU/ml was enough to infect aphid gut and to prevent post-final ecdysis growth of the insect. As a result, the body weight of the infected aphids was significantly reduced (p<0.01). A concentration of 105 CFU/ml of Er. aphidicola caused aphid mortality. In contrast, Er. herbicola demanded 105 CFU/ml to colonize in aphid gut, and seemed to have no effect on insect health. Key Words biological control; Erwinia aphidicola; Erwinia herb/cola; pathogenicity Aphids are one of the most important pest insect the family Enterobacteriaceae (Unterman et al., 1989). groups in agriculture in temperate climatic zones. In addition to this highly-conserved type of endosym- These insects debilitate their host plants both directly biont, many lineages of aphids harbor other types of as sap feeders, toxifiers and pollutive excreters, and intracellular symbionts, so called secondary sym- indirectly as vectors of plant virus diseases.
    [Show full text]