Insect vectors of grapevine Insect vectors of grapevine phytoplasmas in Europephytoplasmas in Europe

A. Alma, R. Tedeschi, F. Lessio, E. GonellaA. Alma, R. Tedeschi, F. Lessio, E. Gonella

DIVAPRA - Entomologia e Zoologia applicate all’Ambiente “C. Vidano”, Università degli Studi di Torino, Via Leonardo da Vinci 44, 10095 Grugliasco (TO). E-mail:

alberto.alma@unito.it

FA 1003FA 0807

Phytoplasmas and viruses management in Grapevine Collections forPhytoplasmas and viruses management in Grapevine Collections forGermplasm Conservation, Mobilization and Evaluation Germplasm Conservation, Mobilization and Evaluation

88--9 May, 2012 , 9 May, 2012 , SOFIA SOFIA -- BULGARIABULGARIA

GRUGLIASCOGRUGLIASCO

University of Torino University of Torino –– Faculty of AgricultureFaculty of Agriculture

Agricultural Science Faculty

Classrooms, administrative

and Dean’s offices

GrugliascoGrugliasco’’s campuss campus

about 30 ha

deanship secretary’s office

(Agricultural Science +

Veterinary Medicine)

students secretariat

classrooms

laboratories

offices and support

services to research and

teaching.

departments

Library

Sheds of Veterinary Medicine Faculty

Veterinary Medicine Faculty

Experimental fields

Greenhouses

Students’centre

Main entrance

Insect vectors of plant pathogens Insect vectors of plant pathogens ((Grapevine, fruit trees, vegetables and ornamentals)

Bioethology and epidemiology

Development of innovative control strategies•Biological and integrated control strategies•Symbiotic control

Invasive speciesInvasive speciesBioethology

Development of biological and integrated control strategies• Neodryinus typhlocybae against Metcalfa pruinosa• Torymus synensis against Dryocosmus kuriphilus

Entomologia e Zoologia applicate allEntomologia e Zoologia applicate all’’Ambiente Ambiente ""C. Vidano"C. Vidano"

Molecular tools for specific discrimination

Vectors

Grapevine phytoplasma diseases in EuropeGrapevine phytoplasma diseases in Europe Flavescence DorFlavescence Doréée (FD)e (FD)

•• EpidemicEpidemic•• Only 1 host plant and 1 insect vectorOnly 1 host plant and 1 insect vector

Scaphoideus titanusScaphoideus titanus•• strictly dependent on grapevinestrictly dependent on grapevine

Bois Noir (BN) Bois Noir (BN) •• EndemicEndemic•• Multiple hosts and probably multiple Multiple hosts and probably multiple insect vectors insect vectors

Hyalesthes obsoletus Hyalesthes obsoletus •• feeds on different erbaceous plants, feeds on different erbaceous plants, occasionally on grapevinesoccasionally on grapevines

Jan. Feb. Mar. Apr. May. Jun. Jul. Aug. Sep. Oct. Nov. Dec.

Eggs

Nymphs

Adults

Eggs

Life cycle of Life cycle of Scaphoideus titanus Scaphoideus titanus -- FDFD

POR.SPAINFRANCEITALYCORSICASWITZ.AUSTRIASLOVENIACROATIAB.H. SERBIAHUNGARYROMANIABULGARIA

Diffusion of Scaphoideus titanus in Europe

Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sep. Oct. Nov. Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sep. Oct. Nov. Dec.Dec.

Nymphs Nymphs

AdultsAdults

EggsEggs

Nymphs Nymphs

Life cycle of Life cycle of Hyalesthes obsoletus Hyalesthes obsoletus -- BNBN

Diffusion of Hyalesthes obsoletus in Europe

““Open cycle Open cycle ””

GRAPEVINEGRAPEVINE

NETTLENETTLE

BINDWEEDBINDWEED

NETTLENETTLE

BINDWEEDBINDWEED

STOLBURSTOLBUR

New potential vectors

New vectors of FD: open cycle?

Dictyophara europaea: present on Clematis vitalba and other weeds within the vineyards

transmission of 16SrV phytoplasmas from C. vitalba to grapevine is possible

Filippin et al., 2009

Orientus ishidae: commonly found in vineyards, lives on many trees

positive to 16SrV phytoplasmas, source unknown

Mehle et al., 2010, 2011 Gaffuri et al., 2011

New vectors?New vectors?

Unknown host plants Clematis vitalba

grapevineD. europaea (?), 16SrV-C

S. titanus

?

Open cycle FD

O. ishidae (?), 16SrV- D

New vectors?New vectors?

Closed cycle FD

New vectors of BN

Hyalesthes scottiHyalesthes scottiHyalesthes luteipesHyalesthes luteipes

Sistematically positive to BN

• Reptalus quinquecostatus can transmit to a feeding medium

Trivellone et al., 2005; Pinzauti et al., 2008; Riedle-Bauer et al., 2008; Alma, 2009;

Reptalus Reptalus spp.spp.

• Anaceratagallia ribauti collected in vineyards can transmit BN to broadbeans

New vectors?New vectors?

Symbiotic control

Direct arthropod control: unbalancing the host’s sex ratio

and disturbing the population development

Control of insect-borne pathogens: antagonistic activity

blocking vector-mediated pathogen transmission

Symbiotic control strategies

New control strategiesNew control strategies

New control strategiesNew control strategies

Complex microbiotas are associated to insects, including phytoplasma vectors

Some of microbial symbionts are predominant in insect microbial communities

They are located in organs and tissues that are fundamental for pathogen’s life cycle (co-localization)

Symbionts can undergo different transmission routes (vertical / horizontal)

Symbiotic control: use of microbial symbiontsSymbiotic control: use of microbial symbionts

A

75 μm

D

*

*

40 μm

B

75 μm

C

210 μm

PROPIDIUM IODIDE staining

BACTEROIDETES probe

SULCIA probe

PROPIDIUM IODIDE staining

BACTEROIDETES probe

SULCIA probe

The microbiota of The microbiota of Hyalesthes obsoletusHyalesthes obsoletus

Large cells typical of ‘Ca. Sulcia

muelleri’massively colonize

the intestine together with other

Bacteroidetes

Gonella et al., 2011

SULCIA probe

BACTERIA probe

280 μm

SULCIA

VIDANIA PURCELLIELLA

Symbiont localizationSymbiont localization

The male reproductive system hosts Sulcia, Purcelliella and Vidania

Gonella et al., 2011

The microbiota of The microbiota of Hyalesthes obsoletusHyalesthes obsoletus

SULCIA BACTERIA probe

VIDANIA PURCELLIELLA

Vertical transmission to the progenyVertical transmission to the progenyThe microbiota of The microbiota of Hyalesthes obsoletusHyalesthes obsoletus

The acetic acid bacteriumThe acetic acid bacterium AsaiaAsaia in in S. titanusS. titanus

Ovaries

Malpighian tubules

TesticlesTesticles

The microbiota associated to The microbiota associated to Scaphoideus titanusScaphoideus titanus

Crotti et al., 2009Crotti et al., 2009

Asaia lives in the gonoducts of

leafhoppers and can be vertically

transmitted by egg smearing

Breaking the infection triangleBreaking the infection triangle

Vitis vinifera

Flavescence dorée

Scaphoideus titanus Phytoplasma

MICROBIOTA

MICROBIAL SYMBIONTS

The The microbiotamicrobiota associated to associated to ScaphoideusScaphoideus titanustitanus