Titled In and Out of Love, the work featured live butterflies, some of which inevitably died and were replaced over the artwork’s run in batches of 400 a week.
The artist’s previous work includes a dead sheep preserved in formaldehyde and a severed cow’s head.
The RSPCA has condemned the deaths.
In a statement, it said: “The RSPCA believes that all animals should be treated with respect and in a manner that minimises the risk of harm.
“In this so-called ‘art exhibition’ butterflies are being forced to exist in the artificial environment of a closed room for their entire lives.
“There would be national outcry if such an exhibition involved any other animal – such as a dog. Just because it is butterflies we are talking about here, doesn’t mean they don’t deserve to be treated with kindness.”
A spokesperson for the Tate Modern said: “Before the show opened in April this year, the artists studio spent over a year replicating the perfect environment for butterflies. Much in the same way that public zoos and butterfly houses do.
“A butterfly expert was employed at considerable cost before and for the whole duration of the Tate Modern show, looking after the butterflies on a daily basis.
“We ensured that perfect living conditions were replicated for the butterflies and this resulted in many of the butterflies enjoying longer lifespans than in the wild due to the high quality of the environment and food provided.”