Tephritids of knapweeds, starthistles and safflower: results of a host choice experiment and the taxonomy of Terellia luteola (Wiedemann) (Diptera: Tephritidae)

A host choice experiment was carried out to determine the host range of some potential biological control agents of yellow starthistle (Centaurea solstitialis), a Mediterranean plant which has become a serious rangeland weed in western USA. This paper describes the results of that experiment and discusses its taxonomic implications. The experiment confirmed the extreme host specificity of some species. However, two reputedly polyphagous species, Acanthiophilus helianthi (Rossi) and Urophora quadrifasciata (Meigen), attacked a narrower range of hosts than expected. The results of this and similar host choice experiments are discussed and it is concluded that this sort of anomaly can be caused by the existence of host races, unrecognized sibling species, or by varieties of plants naturally resistant to attack. These complex patterns of host relationship highlight the need to interpret host catalogue data cautiously, as they oversimplify complex biological systems. The identity of one species reared in the experiment, Terellia luteola (Wiedemann), is discussed; a key is presented for its separation from other Terellia species, and it is removed from synonymy with T. colon (Meigen

Host specificity of Aceria centaureae (Nalepa), a candidate for biological control of Centaurea dίffusa De Lamarck

Κατά τη διάρκεια των ετών 1985 και 1986 έγιναν πειράματα υπαίθρου με το άκαρι Acerea centaureae το οποίο προκαλεί κηκίδες (στα φύλλα κυρίως) του φυτού Centaurea diffusa.Προσβεβλημένα από το άκαρι τμήματα του φυτού C. diffusa τέθηκαν σε επαφή με πειραματικά φυτά ορισμένων ειδών που βρίσκονταν σε κατάλληλο στάδιο ανάπτυξης. Ακολούθησαν περιοδικοί έλεγχοι για τη διαπίστωση ύπαρξης προσβολής από το άκαρι στα πειραματικά φυτά. Παρατηρήθηκε δημιουργία κηκίδων σε όλα τα πειραματικά φυτάίΓ. diffusa είτε αυτά ήταν ελληνικής είτε βορειοαμερικανικής προέλευσης, καθώς και σε μερικά από τα πειραματικά φυτά του είδους Centaurea solstitialis L. Καμία κηκίδα ή άλλο σύμπτωμα προσβολής από το άκαρι δεν παρατηρήθηκε στα άλλα πειραματικά είδη φυτών τα οποία ήταν τα ακόλουθα: Carthamus tinctorius L., Circium creticum (De Lamarck) D'Urvilleελληνικής προέλευσης και έξι (6) είδη του γένους Cirsium βορειοαμερικανικήςπροέλευσης (Η.Π.Α.), τα: cymosum (Greene) Howell, occidentale (Nutt) Jeps,pastrris Howell, andersonii (Gray) Petrak, brevistylum Crong, και undulatum (Nutt.) Spreng.Τα αποτελέσματα αυτά υποδηλώνουν ότι πιθανότατα το άκαρι Aceria centaureae είναι μάλλον ολιγοφάγο είδος το οποίο προσβάλλει μόνον ορισμένα ζιζάνια του είδους Centaurea και επομένως μπορεί να θεωρηθεί ως υποψήφιο είδος για τη βιολογική καταπολέμηση του C. diffusa στις Η.Π.Α. και στον Καναδά.Filed collected rosettes or twigs of Centaurea diffusa De Lamarck, infested by the gall mite Aceria centaureae, were fixed onto appropriately grown and planted test plants of ten different species in the area of Thessaloniki, Greece, in 1985 and 1986. The test plants were inspected for presence of galls and mites a few to several days after their contact with the infested twigs. Gall formation occurred on all of the Centaurea diffusa test plants, either of Greek or U.S. origin, and on some of the Centaurea solstitialis, L. test plants. No galls or other mite damage could be found on the other test plants, which were Carthamus tinctorius L. (safflower), Cirsiton creticion (De Lamarck) D’Urville, of local origin and six Cirsium species of U.S. origin, i.e. cymosum (Greene) J. T. Howell, occidentals (Nutt) Jeps., pastoris Howell, andersonii (Gray) Petrak, brevistylum Crong; and undulation (Nutt.) Spreng. These results suggest that A. centaureae most probably has a very restricted host plant range, feeding only on weedy Centaurea spp. Thus the mite should be considered as a possible candidate for biological control of diffuse knapweed in the U.S.A. and Canada

Untersuchungen über Bionomie, Präimaginalstadien und Verbreitung der europäischen Sorhagenia-Arten (Lepidoptera: Walshiidae).

Die Bionomien der europäischen Arten der Gattung Sorhagenia werden beschrieben. Die Raupe von Sorhagenia lophyrella Douglas lebt einzeln zwischen zusammengesponnenen Blättern von Rhamnus cathartica und Rhamnus saxatilis, die von Sorhagenia rhamniella Zeller gesellig zwischen zusammengesponnenen Blüten von Rhamnus cathartica, jene von Sorphagenia janiszewskae Ridl miniert in den disjährigen Trieben von Rhamnus frangula seltener in anderen Rhamnus-Arten. Sorphagenia lophyrella und Sorhagenia rhamniella überwintern als Ei, Sorhagenia janiszewskae vermutlich als Imago in beiden Geschlechtern. Nach dem Material aus Museen und Privatsammlungen sowie aus eigenen Aufsammlungen wird ein Überblick über die Verbreitung der Arten gegeben. Raupe und Puppe werden beschrieben und abgebildet, Unterscheidungsmerkmale der Raupen angegeben.The bionomics of the european species of the genus Sorhagenia are described. The caterpillar of Sorhagenia lophyrella Douglas lives singly between spun leaves of Rhamnus cathartica and Rhamnus saxatilis, that of Sorhagenia rhamniella Zeller lives sociably between spun blossoms of Rhamnus cathartica, that of Sorphagenia janiszewskae Ridl mines in this years shoots of Rhamnus frangula and more rarely in other species of Rhamnus. Sorphagenia lophyrella and Sorhagenia rhamniella hibernate as eggs, Sorhagenia janiszewskae probably as imago in both sexes. On the basis of material from museums and private collections and from the author's collections a survey is given of the distribution of the species. Caterpillar and pupa are described and illustrated, and distinctive characteristics of the caterpillars are mentioned

A new Eriophyid species (Acari Eriophyoidea) on Salsola spp. (Centrospermae Chenopodiaceae) and a new report for Aceria tamaricis (Trotter)

A new eriophyoid species is described and illustrated. Aceria salsolae n. sp. was observed on Salsola kali L. and S. australis Brown (Centrospermae Chenopodiaceae) in Turkey, Greece and Uzbekistan. Although the mite does not form galls, the infested plants were stunted, deformed, less spiny, and their vigor was impacted. Host specificity tests, carried out in Turkey, indicate that this species is a promising candidate for the biological control of S. australis in the U.S.A. A. tamaricis (Trotter) has been also found on Tamarix smirnensis Bunge in Turkey. Key words: mites, Eriophyidae, weeds, biological control. UNA NUOVA SPECIE DI ERIOFIDE (ACARI ERIOPHYOIDEA) SU SALSOLA SPP. (CENTROSPERMAE CHENOPODIACEAE) E UNA NUOVA SEGNALAZIONE PER ACERIA TAMARICIS (TROTTER) Viene descritta e illustrata una nuova specie di Eriofide. Aceria salsolae sp. n. è stata raccolta su Salsola kali L. e S. australis Brown (Centrospermae Chenopodiaceae), in Turchia, Grecia e Uzbekistan. Le piante infestate mostravano crescita stentata, deformazioni, minore spinosità e ridotto vigore. Prove di specificità dell’ospite, eseguite in Turchia, hanno evidenziato come que- sta specie sia un promettente candidato per il suo controllo di S. australis negli U.S.A. A. tamaricis (Trotter) viene segnalata per la prima volta su Tamarix smirnensis Bunge in Turchia. Parole chiave: acari, Eriophyidae, erbe infestanti, controllo biologico

Taxonomy, distribution, and host specificity of a gall-making mite, Aceria tamaricis (Trotter) (Acari: Eriophyoidea), associated with Tamarix gallica L. (Parietales: Tamaricaceae) in southern France

A population of Aceria tamaricis (Trotter), found in galls collected on Tamarix gallica L. from southern France, has been compared to samples used for the redescription of the species by CASTAGNOLI (1992), pointing out the morphological differences, and to the other species found until now on Tamarix spp., making some taxonomic considerations. The host specificity study reveals that A. tamaricis almost always infests T. gallica while it does not attack T. aphylla (L.) Carsten from USA, T. parviflora D.C. from France and T. ramosis- sima Ledeb from USA. In addition, observations are presented on the biology and distribution of the mite in southern France. Key words: morphology, weeds, biological control. TASSONOMIA, DISTRIBUZIONE E SPECIFICITÀ DI UN ERIOFIDE GALLIGENO, ACERIA TAMARICIS (TROTTER) (ACARI: ERIOPHYOIDEA), ASSOCIATO A TAMARIX GALLICA L. (PARIETALES: TAMARICACEAE) IN FRANCIA MERIDIONALE Sono riportate le caratteristiche morfologiche di una popolazione di Aceria tamaricis (Trotter), galligeno su Tamarix gallica L. in Francia meridionale, e confrontate con quella utilizzata per la ridescrizione della specie eseguita da CASTAGNOLI (1992), evidenziando le differenze, e con le altre specie finora note su Tamarix spp. Lo studio della specificità ha rilevato che A. tamaricis infesta quasi sempre T. gallica mentre non attacca T. aphylla (L.) Carsten, T. parviflora D.C. e T. ramosissima Ledeb. Sono state eseguite, inoltre, osservazioni sulla biologia e distribuzione geografica in Francia meridionale. Parole chiave: morfologia, infestanti, controllo biologico

HIV-1 Tat complexes reveal subunit composition of active P-TEFb and stable association with 7SKsnRNP

International audiencen.

Premature Activation of the SLX4 Complex by Vpr Promotes G2/M Arrest and Escape from Innate Immune Sensing

SummaryThe HIV auxiliary protein Vpr potently blocks the cell cycle at the G2/M transition. Here, we show that G2/M arrest results from untimely activation of the structure-specific endonuclease (SSE) regulator SLX4 complex (SLX4com) by Vpr, a process that requires VPRBP-DDB1-CUL4 E3-ligase complex. Direct interaction of Vpr with SLX4 induced the recruitment of VPRBP and kinase-active PLK1, enhancing the cleavage of DNA by SLX4-associated MUS81-EME1 endonucleases. G2/M arrest-deficient Vpr alleles failed to interact with SLX4 or to induce recruitment of MUS81 and PLK1. Furthermore, knockdown of SLX4, MUS81, or EME1 inhibited Vpr-induced G2/M arrest. In addition, we show that the SLX4com is involved in suppressing spontaneous and HIV-1-mediated induction of type 1 interferon and establishment of antiviral responses. Thus, our work not only reveals the identity of the cellular factors required for Vpr-mediated G2/M arrest but also identifies the SLX4com as a regulator of innate immunity

Co-operation of BRCA1 and POH1 relieves the barriers posed by 53BP1 and RAP80 to resection

In G2 phase cells, DNA double-strand break repair switches from DNA non-homologous end-joining to homologous recombination. This switch demands the promotion of resection. We examine the changes in 53BP1 and RAP80 ionizing radiation induced foci (IRIF) in G2 phase, as these are factors that restrict resection. We observed a 2-fold increase in the volume of 53BP1 foci by 8 h, which is not seen in G1 cells. Additionally, an IRIF core devoid of 53BP1 arises where RPA foci form, with BRCA1 IRIF forming between 53BP1 and replication protein A (RPA). Ubiquitin chains assessed using a-FK2 antibodies are similarly repositioned. Repositioning of all these components requires BRCA1’s BRCT but not the ring finger domain. 53BP1, RAP80 and ubiquitin chains are enlarged following POH1 depletion by small interfering RNA, but a devoid core does not form and RPA foci formation is impaired. Co-depletion of POH1 and RAP80, BRCC36 or ABRAXAS allows establishment of the 53BP1 and ubiquitin chain-devoid core. Thus, the barriers posed by 53BP1 and RAP80 are relieved by BRCA1 and POH1, respectively. Analysis of combined depletions shows that these represent distinct but interfacing barriers to promote loss of ubiquitin chains in the IRIF core, which is required for subsequent resection. We propose a model whereby BRCA1 impacts on 53BP1 to allow access of POH1 to RAP80. POH1-dependent removal of RAP80 within the IRIF core enables degradation of ubiquitin chains, which promotes loss of 53BP1. Thus, POH1 represents a novel component regulating the switch from nonhomologous end-joining to homologous recombination