why we need butterfly in our cities?

Threatened by loss of habitat, industrial agriculture and climate change, butterfly populations have been dwindling in recent years in the UK.
Butterfly Conservation, a British charity devoted to saving butterflies and moths, says that 76 percent of species have declined over the past four decades.
The loss is particularly evident in urban areas, where green spaces are shrinking and butterflies are disappearing more rapidly in the last 20 years: a 69 percent fall compared to 45 percent in the countryside.
It's a significant loss, because butterflies -- the most-studied insects in the UK -- act as an indicator for the well-being of a wider ecosystem and the status of several species of insects that are not examined as thoroughly.
According to Butterfly Conservation, restoring butterfly populations in gardens, urban green spaces and the countryside can bring substantial benefits to several other species and improve the health, wealth and well-being of the human population.
A message that resonates strongly with British butterfly conservationist Dan Danahar, who's working to bring some of the UK's 59 species back to urban areas.