1

 - Large-sized aphid (about 3mm) → 2

 - Small-medium sized aphid (about 2mm) → 3

2

 - Apterous green or pink, large and elongate; antennae same length as body, slightly pigmented; cornicles long, cylindrical and darkening towards the tip; cauda long and light-coloured; alate without abdominal pigmentation; antennae and cornicles darkening towards the tip; cauda long and light-coloured
Macrosiphum euphorbiae

 - Apterous green or pink, large and elongate; antennae same length as body, slightly pigmented; cornicles long, cylindrical and darkening towards the tip; cauda long and light-coloured; alate without abdominal pigmentation; antennae and cornicles darkening towards the tip; cauda long and light-coloured
Aulacorthum solani

3

 - Apterous with cornicles slightly swollen, green to yellowish, colony includes pinkish individuals which are the future alates (nymphs); cornicles slightly swollen on inner side: alate with a dorsal patch jagged and perforated
Myzus persicae

 - Apterous with cornicles straight and short → 4

4

 - Apterous matt black to dark olive green, colony includes individuals (nymphs) showing waxy white stripes, cornicles straight, black; cauda digitate and squat;  alate abdomen shows pigmented stripes with contour irregular 
Aphis fabae

 - Apterous with another colour → 5

5

 - Apterous yellowish to greenish with glossy aspect; cornicles pale except at end which is darkened, brownish;  alate with marginal sclerites, cornicles, cauda and antennae slightly darkened
Aphis nasturtii

 - Apterous olive green to brownish; cornicles black uniformly pigmented, darker than cauda; alate with marginal and post-cornicular sclerites strongly darkened; cornicles dark; cauda slightly lighter than cornicles
Aphis frangulae or Aphis gossypii (*)
(*) group of species indistinguishable by morphological criteria 

See visual identification