"The disease is not known to be present in the UK. To maintain PZS the UK must demonstrate that we are actively looking for plane wilt and that we have not yet found it," said the association.
It is working with the Forestry Commission to undertake PZS surveys and produce annual reports, and is currently carrying out the 2016 survey, due for completion at the end of September.
"Perhaps the most obvious symptom is significant sections of canopy in the tree where the leaves have become completely desiccated but have been retained on the tree," it said, stressing that the disease affects only plane trees.
Individuals can report a suspected sighting via the Forestry Commission's Tree Alert service (forestry.gov.uk/treealert). "However it is important to note that further investigation by a professional will be required in order to confirm the diagnosis," said the LTOA. An identification guide to the disease can be downloaded at ltoa.org.uk.
Meanwhile, a report in The Sunday Telegraph on 31 July warned that London vistas such as the Mall "could be rendered unrecognisable for decades" by the arrival of the disease. Arboricultural Association chairman Jago Keen said its impact would be "catastrophic", adding: "We are very concerned because we do have something of a track record of letting diseases get in here." The disease has already spread to central France, causing the loss of many historic plane trees.