title: Transmission of Grapevine virus A and Grapevine leafroll-associated virus 1 and 3 by Heliococcus bohemicus (Hemiptera: Pseudococcidae) Nymphs From Plants With Mixed Infections.
abstract: Mealybugs (Hemiptera: Pseudococcidae) represent a serious threat for viticulture as vectors of phloem-restricted viruses associated with the grapevine rugose wood and leafroll diseases. Heliococcus bohemicus (Šulc) is known to be involved in the spread of these two viral diseases, being a vector of the Grapevine virus A (GVA) and the Grapevine leafroll-associated virus 1 and 3 (GLRaV-1 and GLRaV-3). This study investigated the acquisition and transmission efficiency of H. bohemicus fed on mixed-infected plants. Nymphs were field-collected onto GVA, GLRaV-1, and GLRaV-3 multiple-infected grapevines in two vineyards in North-Western Italy, and were used in transmission experiments under controlled conditions. Even if most of the collected nymphs were positive to at least one virus, transmission occurred only to a low number of test grapevines. The transmission frequency of GLRaV-3 was the highest, whereas GVA was transmitted to few test plants. The transmission of multiple viruses occurred at low rates, and nymphs that acquired all the three viruses then failed to transmit them together. Statistical analyses showed that the three viruses were independently acquired and transmitted by H. bohemicus and neither synergistic nor antagonistic interactions occurred among them. GVA and GLRaVs transmission efficiencies by H. bohemicus were lower than those reported for other mealybug vectors. This finding is consistent with the slow spread of leafroll and rugose wood diseases observed in Northern Italy, where H. bohemicus is the predominant vector species.
authors.affiliation: DISAFA, Università degli Studi di Torino, Largo Paolo Braccini 2, 10095 Grugliasco, Italy (sabrina.bertin@crea.gov.it; vicavalieri78@gmail.com; dario.sacco@unito.it; domenico.bosco@unito.it), CREA - PAV, Via C.G. Bertero 22, 00156 Roma, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Bertin
authors.affiliation: DISAFA, Università degli Studi di Torino, Largo Paolo Braccini 2, 10095 Grugliasco, Italy (sabrina.bertin@crea.gov.it; vicavalieri78@gmail.com; dario.sacco@unito.it; domenico.bosco@unito.it), CNR - IPSP, Sezione Secondaria di Bari, Via Amendola 122/D, 70126 Bari, Italy.
authors.forename: V
authors.initials: V
authors.lastname: Cavalieri
authors.affiliation: CNR - IPSP, Largo Paolo Braccini 2, 10095 Grugliasco, Italy (ivana.gribaudo@ipsp.cnr.it).
authors.forename: I
authors.initials: I
authors.lastname: Gribaudo
authors.affiliation: DISAFA, Università degli Studi di Torino, Largo Paolo Braccini 2, 10095 Grugliasco, Italy (sabrina.bertin@crea.gov.it; vicavalieri78@gmail.com; dario.sacco@unito.it; domenico.bosco@unito.it).
authors.forename: D
authors.initials: D
authors.lastname: Sacco
authors.affiliation: CNR - IPSP, Strada delle Cacce 73, 10135 Torino, Italy (cristina.marzachi@ipsp.cnr.it), and.
authors.forename: C
authors.initials: C
authors.lastname: Marzachì
authors.affiliation: DISAFA, Università degli Studi di Torino, Largo Paolo Braccini 2, 10095 Grugliasco, Italy (sabrina.bertin@crea.gov.it; vicavalieri78@gmail.com; dario.sacco@unito.it; domenico.bosco@unito.it), CNR - IPSP, Strada delle Cacce 73, 10135 Torino, Italy (cristina.marzachi@ipsp.cnr.it), and domenico.bosco@unito.it.
authors.forename: D
authors.initials: D
authors.lastname: Bosco
mesh_terms: D000818:Animals; D029381:Closteroviridae / Q000502:physiology*; D052677:Flexiviridae / Q000502:physiology*; D006430:Hemiptera / Q000254:growth & development / Q000502:physiology* / Q000821:virology; D007558:Italy; D009758:Nymph / Q000254:growth & development / Q000502:physiology / Q000821:virology; D010935:Plant Diseases / Q000821:virology*; D017423:Sequence Analysis, RNA; D027843:Vitis / Q000821:virology*
keywords: Leafroll; Mealybug; Rugose wood; Vitis vinifera