Morphological characters

1.2-2.4 mm, dark green and globular in shape.
Apterous: reddish spot around insertion points of cornicles.
Alate: antennae dark and shorter than body; marginal sclerites on abdomen and a larger one at base of cornicles; cornicles straight, pigmented, with a constriction at tip, cauda short and pigmented.

See identification file

Life cycles

Dioecious  holocyclic .
Anholocyclic on Poaceae in zones with mild climate.

Host plants

Primary host: Prunus padus (bird cherry), 3rd photo shows a colony on Prunus padus
Secondary hosts: cultivated Poaceae: Triticum (wheat), Hordeum (barley), Zea (maize) and also wild species.

Agronomic impact

R. padi colonizes spring cereals which are the most badly affected. It causes direct damage by its injections in the leaves of grass species which roll up into a spiral.
During the summer, it migrates and develops on maize. In the autumn, at the end of the growing cycle of maize, the anholocyclic populations migrate onto the seedbeds and regrowing shoots of winter cereals where they transmit viruses responsible for barley yellow dwarf disease  (BYDV) (see photo of damage above).

Natural enemies

Parasitoids :

• Aphelinus abdominalis
• Aphelinus flavipes
• Aphelinus asychis
• Aphelinus chaonia
• Aphidius avenae
• Aphidius colemani
• Aphidius matricariae
• Aphidius rhopalosiphi
• Binodoxys angelica
• Diaeretiella rapae
• Ephedrus persicae
• Ephedrus plagiator
• Monoctonus caricis
• Praon abjectum
• Praon gallicum
• Praon volucre
• Trioxys auctus