The rostrum (or labium) is placed on the ventral part of the head. It consists of 4 segments with unequal length (the last one can be very long).

 The rostrum is made of two mandibular stylets protecting two maxillary stylets along their entire length. The internal structure  of the maxillary stylets is highly complex.

Morphologie du rostre

Schéma H. Weber

Cinara tujafilina : adulte ailé
Sitobion avenae : adulte aptère

short rostrum : Sitobion avenae

                                                                      long rostrum : Cinara tujafilin


Cinara tujafilina : adulte ailé

long rostrum : Cinara tujafilina

short rostrum : Sitobion avenae

Modification date: 09 April 2024 | Publication date: 09 November 2010 | By: Evelyne Turpeau, Maurice Hullé, Bernard Chaubet