wingspan : male 75/84, female 77/80 mm
Heliconius cydno is an extremely variable butterfly, and the presently described ssp and forms are probably not very reliable.
all we can say is :
- East of the Reserve, and at 1400 m, we found exclusively yellow forms (las Juntas - page 992) ;
- West of the Reserve, at sea level, exclusively white forms (Calderón - page 999) ;
- between the two : - at 6/800 m, we found about 50% white and 50% yellow forms (Lita - page 413),
- and farther West, at 7/900 m, the ratio was two white for one yellow (Alto tambo - page 916) ;
- and at los Cedros, 1200 m, near Chontal, and near Pedro Vicente Maldonado, 600 m, many yellow forms, and just two white ones, (on this page).
it is can also be noted that the HW border varies:
- far from Colombia (Bilsa and los Cedros) - from wide to very wide,
- close to Colombia (las Juntas, Lita, Alto Tambo, Calderón) - from almost absent to narrow, except in Lita where it can be wide.
at los Cedros we found few male white forms but all females were yellow, and always wide HW rims.
