Frons

Frons

The shape of the head and more particularly of the frons is also an important criterion for identification of genera and sometimes of species. .

The frons of aphids can show differences in the medial sinus: more or less pronounced (A, B), convex (C), concave (D) or even bearing frontal tubercles (E, F):

Différentes formes des sinus frontaux

Diagram F. Leclant

A: weakly sinuous  B: sinuous with medial frontal tubercle distinct (genus Aphis)  C: frons convex ( Pemphigus bursarius)  D: frons with divergent margins (Macrosiphum euphorbiae)  E: frontal tubercles straight (Aulacorthum solani)  F: frontal tubercles convergent (Myzus persicae)