To date, around 1 million insect species have been identified throughout the world.
But, while that may be a mind-boggling number, biologists estimate that there remains at least 4 million more left undiscovered--many of which may lie deep in the heart of the world's largest rainforest.
Source:
http://www.treehugger.com/files/2010/04/amazon-expedition-aims-to-collect-100000-bugs.php
