...have always been sort of amazed by the 'paired' nature of the Monarch butterfly proboscis; careful inspection of a decent image...it looks as though there are two of them (what is plural of probiscus?!) fused together...
R5MkII & 200-800 @ about 600
...it turns out that "The proboscis is vital to the survival of a butterfly and they cannot live if it has not formed properly. When they first emerge from their chrysalis their proboscis isn’t fully developed. In fact, the proboscis is actually split in two and they must curl and uncurl it repeatedly until it fuses or zips together. Amazing!"
Butterflies are born with a split proboscis. This video shows the process of fusing the proboscis by repeatedly curling it once the butterfly has emerged.
www.lewisginter.org
EDIT: first monarchs in our neighborhood (the midwest USA) in at least a decade