The company warns that in extreme cases it can cause problems to foundations, hard surfaces, drains and walls.
Knotweed Control said the cost, complexity and length of time required to control the plant "vary hugely".
CABI is experimenting with the psyllid, Aphalara itadori with large scale field cage trials in 2014.
The company warned: "Whichever method is used it must be undertaken with care, at the right time of year, in the correct conditions following all current legislation and good practice requiring cunning, diligence and persistence with a monitoring phase. Incorrect treatment can cause the knotweed to response by spreading rapidly spanning multiple land owners, growing with deformed form which means treatment is less effective or can even force it into dormancy all storing up problems and can get very complicated.Under the Wildlife and Countryside Act (1981) it is illegal to spread knotweed into the wild. Under the Crime and Policing Act 2014 an Anti-Social Control Order (ASBOs) can be brought against those who fail to act. All knotweed material is classed as "controlled waste" under the Environmental Protection Act (1990) and can be "hazardous waste". Special conditions can be added to a planning applications Under the Town and Country Planning Act (1990). EU Regulation on invasive alien species (2014) on the prevention and management of the introduction and spread of invasive non-native species including Japanese knotweed.