The aphids use their cornicles to release a defensive substance and an alarm pheromone in case of attack by a predator.

The cornicles are highly variable in shape, colour and length. They are a feature commonly used as identification criteria for adult forms of different species. You can therefore find cornicles in various shapes and sizes: short cone-shaped (A), swollen (B), or straight (C), medium-sized ones that can be swollen (D) or straight (E), long ones (F) or even very long straight (G) or swollen ones (H). In certain species, the cornicles are reduced to a pore, in others even completely absent. Cornicle shape and form can also vary within the same species, according to the stage or morph.

Différents types de cornicules
Cinara sp : adulte aptère
Brevicoryne brassicae : adulte ailé
Rhopalosiphum padi : larviposition
Megoura viciae : adulte aptère

A : Cinara spp.

B : Brevicoryne brassicae

C : Rhopalosiphum padi

D : Megoura viciae

Sitobion avenae : adulte aptère
Aulacorthum solani : adulte ailé
Acyrthosiphon pisum : adulte aptère © INRA, Bernard Chaubet
Wahlgreniella arbuti : adulte ailé

E : Sitobion avenae

F : Aulacorthum solani

G : Acyrthosiphon pisum

H : Wahlgreniella nervata

Modification date : 07 February 2023 | Publication date : 23 November 2010 | Redactor : Evelyne Turpeau, Maurice Hullé, Bernard Chaubet