Males: evident different, the male of h. Marginatum have uniform festoons whilst the median festoon of h. Scupense has different colour.
For both males and females : the colour of the legs is uniform (yellowish) in scupense but are decolored in the junctions (rings) and in the posterior side
Hy qcupense is generally more thin
These are gerenal and easy differences
In the book of walker (available in internet) there are much more details. I could find it to you.
You said “For both males and females : the colour of the legs is uniform (yellowish) in scupense but are decolored in the junctions (rings) and in the posterior side”,
Is it means H. scupense has pal rings between segments of legs and pal pathes on the dorsal surface of legs?
while walker in his book (page 95, 5 key of female and page 96, 8 key of male) said:
"Leg colouration is without pale rings (there may be indistinct pale patches on the dorsal surface of leg segments, legs have a yellow to pale orange colour and are unusually long)."
Also about H. marginatum in pages 115-116 walker said: " Leg colouration is with pale rings (also there are patches of pale colour along the dorsal surfaces)."
walker in his book (page 95, 5 key of female and page 96, 8 key of male) said:
"Leg colouration is without pale rings (there may be indistinct pale patches on the dorsal surface of leg segments, legs have a yellow to pale orange colour and are unusually long)."