The Colorado beetle has been eradicated from the Island but is endemic in Normandy and other parts of France.
The current hot weather and north-easterly wind – at a time when the insects take flight – are conducive to enabling them to fly across the short stretch of sea from Normandy.
If they become established in the Island they pose a threat to the Jersey Royal crop, salad plants, tomatoes and parsley which are all grown commercially.
Sightings should be reported to environment@gov.je.