Know more

Our use of cookies

Cookies are a set of data stored on a user’s device when the user browses a web site. The data is in a file containing an ID number, the name of the server which deposited it and, in some cases, an expiry date. We use cookies to record information about your visit, language of preference, and other parameters on the site in order to optimise your next visit and make the site even more useful to you.

To improve your experience, we use cookies to store certain browsing information and provide secure navigation, and to collect statistics with a view to improve the site’s features. For a complete list of the cookies we use, download “Ghostery”, a free plug-in for browsers which can detect, and, in some cases, block cookies.

Ghostery is available here for free: https://www.ghostery.com/fr/products/

You can also visit the CNIL web site for instructions on how to configure your browser to manage cookie storage on your device.

In the case of third-party advertising cookies, you can also visit the following site: http://www.youronlinechoices.com/fr/controler-ses-cookies/, offered by digital advertising professionals within the European Digital Advertising Alliance (EDAA). From the site, you can deny or accept the cookies used by advertising professionals who are members.

It is also possible to block certain third-party cookies directly via publishers:

Cookie type

Means of blocking

Analytical and performance cookies

Realytics
Google Analytics
Spoteffects
Optimizely

Targeted advertising cookies

DoubleClick
Mediarithmics

The following types of cookies may be used on our websites:

Mandatory cookies

Functional cookies

Social media and advertising cookies

These cookies are needed to ensure the proper functioning of the site and cannot be disabled. They help ensure a secure connection and the basic availability of our website.

These cookies allow us to analyse site use in order to measure and optimise performance. They allow us to store your sign-in information and display the different components of our website in a more coherent way.

These cookies are used by advertising agencies such as Google and by social media sites such as LinkedIn and Facebook. Among other things, they allow pages to be shared on social media, the posting of comments, and the publication (on our site or elsewhere) of ads that reflect your centres of interest.

Our EZPublish content management system (CMS) uses CAS and PHP session cookies and the New Relic cookie for monitoring purposes (IP, response times).

These cookies are deleted at the end of the browsing session (when you log off or close your browser window)

Our EZPublish content management system (CMS) uses the XiTi cookie to measure traffic. Our service provider is AT Internet. This company stores data (IPs, date and time of access, length of the visit and pages viewed) for six months.

Our EZPublish content management system (CMS) does not use this type of cookie.

For more information about the cookies we use, contact INRA’s Data Protection Officer by email at cil-dpo@inra.fr or by post at:

INRA
24, chemin de Borde Rouge –Auzeville – CS52627
31326 Castanet Tolosan CEDEX - France

Dernière mise à jour : Mai 2018

Menu Logo Principal

Encyclop'Aphid : l'encyclopédie des pucerons

Encyclop'APHID

Dioecious holocyclic cycle (2)

In many dioecious holocyclic Aphididae, the oviparous, apterous females are born on the primary host by alate gynopara. The alate males formed on the secondary hosts join the apterous oviparous females.

In type 2 dioecious holocyclic species, the alate gynopara, formed in the summer on the secondary host, migrate to the primary hosts. There they give birth to oviparous females. The alate males, which belong to the same generation as the gynopara, arrive in their turn on the primary hosts to mate with oviparous females. The two sexual morphs are therefore a generation apart.
When the egg hatches, the fundatrix give birth to several generations of fundatrigenia which develop on the primary host in spring. Then alatemigrants leave to colonize the secondary hosts at the end of spring.

This is the case for:

  • The bird cherry oat aphid: Rhopalosiphum padi which alternates between Prunus padus (H I) and a range of Poaceae (HII) 
  • The black bean aphid: Aphis fabae which alternates between various primary hosts (fusain, viburnum, Philadelphus/mock orange) and many secondary hosts (such as Fabaceae, Chenopodiaceae, Solanaceae)
  • The rose-grain aphid: Metopolophium dirhodum which alternates between roses (HI) and diverse Poaceae (HII)
Cycle holocycle dioecique

Illustration with the cycle of Rhopalosiphum padi:

Alternance d'hôtes entre l'hôte primaire (HI) Prunus padus (merisier à grappes) et les hôtes secondaires (HII) graminées cultivées ou sauvages

Rhopalosiphum padi : accouplement
Rhopalosiphum padi : oeufs sur Prunus padus
Rhopalosiphum padi : fondatrice sur Prunus padus

Copulation on Prunus padus

Eggs on Prunus padus

Fundatrix onr Prunus padus

Rhopalosiphum padi : adulte aptère et larves sur blé
Rhopalosiphum padi : adulte ailé

Apterous virginopara and larvae on barley

Winged virginopara on wheat