“The idea of keeping crickets for their songs is rooted in ancient Chinese and Japanese culture. But I didn’t want to cage them, but let them be free,” he previously wrote in a letter to The Independent.
A plant scientist who released 1,000 foreign crickets into his garden because he liked the sound they made has been given a warning by police for endangering native wildlife.
He said he did not think that they had done any damage or posed any environmental risk, and stressed that they would only last for the summer because their lifespan was just one to two months.
“The idea of keeping crickets for their songs is rooted in ancient Chinese and Japanese culture. But I didn’t want to cage them, but let them be free,” he previously wrote in a letter to The Independent.
However, Thames Valley Police ruled that his actions contravened the Wildlife and Countryside Act and issued him with an Adult Restorative Disposal, a form of “restorative justice” used for low-level offences to avoid going through the court system.
PC Dean Kingham, a wildlife officer, said: "The man released the insects as he liked the sound they made.
"While this sounds innocent, the introduction of animals not normally resident in the population can cause, at best, disruption to the local wildlife.
"At worst, it can cause damage by spreading disease or creating artificial populations."
He added that Mr Emlyn-Jones has used traps bought from a pest control company to try to eradicate the Mediterranean crickets, which are a common food source for pet reptiles.
Neighbours in Divinity Road, Oxford, said they had enjoyed the "cheerful chirping” of the insects.
Patrick Gray, 65, a former Oxford city councillor, said: "I was intrigued. It was very loud and very cheerful and sounded like a night in the Mediterranean. However, I would not be in favour of people bringing new species in."
The insects' native habitat is tropical and sub-tropical regions of Asia, Africa, and Europe, and they produce their distinctive chirp by rubbing their two outer wings together.
James Hogan, a curator at the Oxford University Museum of Natural History, said: "The problem with releasing alien species is that you do not know what effect they may have.
"They might carry diseases. Gryllus bimaculatus make loud chirps, but I'm sure Mr Emlyn-Jones can buy CDs with cricket songs on instead."
Mr Emlyn-Jones, who is a private maths and science tutor and a church warden, declined to comment on his police warning.