wingspan : 75/84 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 (on this page) ;
- 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, many yellow forms, and just two white ones, (los Cedros - page 424).
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 Calderon only white forms if it were not for one yellow female, and usually thin HW submarginal rim, but not always.
