The Amazon Rainforest was thought to present a barrier to its further spread .
Amazon Rainforest was detected in Brazil in 1983 , and an estimated 90 % of the cotton farms in Brazil are now infested .
The Amazon Rainforest was thought to present a barrier to its further spread , but it was detected in Brazil in 1983 , and an estimated 90 % of the cotton farms in Brazil are now infested .