SAO PAULO (REUTERS) - Brazil's Agriculture Ministry declared a state of emergency in Minas Gerais, the main coffee-producing state, due to the threat of a crop-damaging insect known as the coffee borer, the government's national gazette said on Thursday.

The ministry justified its decision by saying that the insect poses a threat due to its "short life cycle and potential for a major proliferation".

Declaring a state of emergency allows officials to adopt quick measures in response to the threat, such as lifting restrictions on the import of commercial pesticides that have not yet been cleared for local use by regulators.

The ministry took similar emergency measures earlier this year over a caterpillar infestation in Brazil's main soy, corn and cotton producing states such as Mato Grosso.

The coffee belt is particularly vulnerable after more than a year of falling prices for the commodity and the recent dry, hot weather that is believed to have trimmed potential output from the new crop by 11 per cent, according to a survey of market sources published by Reuters this month.

The ministry cited the "limited capacity to respond to the threat (of the coffee borer) due to the lack of efficient alternatives for its management".

The coffee borer tunnels into coffee fruit and destroys the maturing beans, hurting producers returns.

Minas Gerais accounts for half of the coffee produced in Brazil, itself the world's largest supplier of arabica coffee.