Found this insect in São Paulo/Brazil. Its length is ~2cm
Any help to identify this insect would be appreciated.
Also see my video
Well, it's a type of firefly, belongs to the order of 'Coleoptera' (beetles), suborder of 'Polyphaga', family of 'Lampyridae' (firefly beetles). It's quite similar to the 'Photinus obscurellus' species (and probably the same species too), however it doesn't always have a black head like yours, however, articles have suggested that firefly species in Brazil (Sao Paulo State) have 'adapted to mesophyl tropical forests, secondary growths, marshy areas, and open fields' (source = https://www.researchgate.net/publication/233574632_Fireflies_Coleoptera_Lampyridae_from_Southeastern_Brazil_Habitats_Life_History_and_Bioluminescence).
This image is from Google Images (more specifically : http://bugguide.net/node/view/194980/bgimage)