Male Monarch Mating with Heliconius Female

I found this at our local butterfly exhibit. At first I thought the female was another monarch obscured from my view.
On closer examination I found out he was mating with a heliconian butterfly. This didn't just occur once, but at least twice at the same time; two separate monarchs and two seperate Heliconiinae females. Either the first male left and returned or another male came back to mate with the same female later. It seems they acted quite naturally without any prompting.

Later I tried googling to see if I could find an explanation. I figured this must occur commonly in butterfly farms, gardens and in captivity, but not in the wild. My search came up dry. There seems to be speculation with how male monarchs pick mates. One site had a PDF suggesting wing size. This butterfly is a lot smaller than a monarch. Wing size doesn't explain this reason. I'm thinking it may have to do with the thorax. Both have black and white spotted thoraxes.

But then again, some things in nature just can't be explained....

Category:

Science & Technology

Tags:

• Monarch
• butterfly
• mating
• other
• species
• heliconian
• Danainae
• Heliconiinae
• Heliconius
• copulation
• copulating

[MerleundMerlin]

Hello BugFolk,

the Monarch butterfly is quite well known for this behavior. The male courts every flying object of approx. the right size. (Then, probably recognises females by odor.) The female is the knocked to the ground and "raped". The courtship behavoir in Monarchs is like that. This can cause a considerable damage to the non-Monarch female butterfly population in butterfly gardens. The same behavoir can be seen in the wild, but rarely, as there is usually enough space for an escape.