Know more

About cookies

What is a "cookie"?

A "cookie" is a piece of information, usually small and identified by a name, which may be sent to your browser by a website you are visiting. Your web browser will store it for a period of time, and send it back to the web server each time you log on again.

Different types of cookies are placed on the sites:

  • Cookies strictly necessary for the proper functioning of the site
  • Cookies deposited by third party sites to improve the interactivity of the site, to collect statistics

Learn more about cookies and how they work

The different types of cookies used on this site

Cookies strictly necessary for the site to function

These cookies allow the main services of the site to function optimally. You can technically block them using your browser settings but your experience on the site may be degraded.

Furthermore, you have the possibility of opposing the use of audience measurement tracers strictly necessary for the functioning and current administration of the website in the cookie management window accessible via the link located in the footer of the site.

Technical cookies

Name of the cookie


Shelf life

CAS and PHP session cookies

Login credentials, session security



Saving your cookie consent choices

12 months

Audience measurement cookies (AT Internet)

Name of the cookie


Shelf life


Trace the visitor's route in order to establish visit statistics.

13 months


Store the anonymous ID of the visitor who starts the first time he visits the site

13 months


Identify the numbers (unique identifiers of a site) seen by the visitor and store the visitor's identifiers.

13 months

About the AT Internet audience measurement tool :

AT Internet's audience measurement tool Analytics is deployed on this site in order to obtain information on visitors' navigation and to improve its use.

The French data protection authority (CNIL) has granted an exemption to AT Internet's Web Analytics cookie. This tool is thus exempt from the collection of the Internet user's consent with regard to the deposit of analytics cookies. However, you can refuse the deposit of these cookies via the cookie management panel.

Good to know:

  • The data collected are not cross-checked with other processing operations
  • The deposited cookie is only used to produce anonymous statistics
  • The cookie does not allow the user's navigation on other sites to be tracked.

Third party cookies to improve the interactivity of the site

This site relies on certain services provided by third parties which allow :

  • to offer interactive content;
  • improve usability and facilitate the sharing of content on social networks;
  • view videos and animated presentations directly on our website;
  • protect form entries from robots;
  • monitor the performance of the site.

These third parties will collect and use your browsing data for their own purposes.

How to accept or reject cookies

When you start browsing an eZpublish site, the appearance of the "cookies" banner allows you to accept or refuse all the cookies we use. This banner will be displayed as long as you have not made a choice, even if you are browsing on another page of the site.

You can change your choices at any time by clicking on the "Cookie Management" link.

You can manage these cookies in your browser. Here are the procedures to follow: Firefox; Chrome; Explorer; Safari; Opera

For more information about the cookies we use, you can contact INRAE's Data Protection Officer by email at or by post at :


24, chemin de Borde Rouge -Auzeville - CS52627 31326 Castanet Tolosan cedex - France

Last update: May 2021

Menu Logo Principal

Encyclop'Aphid : l'encyclopédie des pucerons


Circulative viruses : persistent transmission

The circulative viruses travel following a complicated circuit in the aphid’s body but they do not replicate. They are acquired during the more lengthy feeding phases when the sap fabricated in the phloem is being absorbed. They circulate through the aphid’s digestive system then the salivary glands, after which they are ready to be injected into new plants.

The transmission of circulative viruses has been particularly well described in the Luteoviridae. Once the aphid has ingested the viral particles they flow into the cavity of the digestive tube with the phloem sap as far as the mid- or distal part of the-intestine. When the virus arrives near these tissues, the virus crosses the first epithelial barrier to enter the insect’s general cavity (haemocoel). In this compartment, the viruses appear to fix onto a protein synthesized by the aphid’s endosymbiotic bacteria. This virus-protein interaction is thought to provide the viral particles with protection against the insect’s immune system.

The viruses diffuse into the haemocoel from the hind region of the aphid upto cells in the salivary glands which they pass through a second time where they mix with the fresh salivary secretions. This mixture with the viral particles will be released in the plant’s phloem tissues. In this process involving circulative viruses, the aphid remains infectious for a long time, even beyond moulting. This transmission process, known as the persistent mode, involves a close, highly specific interaction between the virus and its vector.

accés direct aux vidéos

transmission of the moderate beet yellow virus 
by Myzus persicae