The number of insects in the world has fallen by 45 per cent in the past 35 years. Scientists say this could be dangerous for humans. A report on insect numbers has been published in the journal ‘Science'. It says the human population has doubled since 1980 while the number of insects has nearly halved. One of the biggest reasons for this loss of insects is deforestation. Many of the places where insects live are disappearing because of new cities and land being used for farming. Another reason is global warming. Scientists say that in the UK, the number of beetles, butterflies, bees and wasps has fallen by up to 60 per cent. Many countries are worried about the disappearance of bees and butterflies.
Scientists say the decline in insect populations will lead to many problems for humans. One of the biggest dangers is that there will be fewer insects to pollinate flowers. This means that farmers will have problems growing food. The lead author of the report, professor Rodolfo Dirzo, said falling numbers of insects could also lead to more disease in humans. He said rats and mice would have less food to eat so they will move to cities and bring diseases with them. Dr Ben Collen from London University said we needed to stop more insects from dying. He added that scientists must understand, "what species are winning and losing in the fight for survival". He said this knowledge would help us to protect the "helpful" insects.