Japanese knotweed is fast becoming a problem in some areas of the UK. It grows very quickly and can be expensive to remove by hand costing anything up to £150m a year to control. It will soon be under attack from another alien in the form of an insect. The Department for Environment, Food and Rural Affairs have approved the release of an insect called the psyllid which eats the weed. In tests the insect has fed on sap from the stems of knotweed, causing the plant to die back and has ignored other similar native plants. It will be released in two locations initially under close supervision to see whether the plan works before being released at another six sites. I’m not convinced myself, that releasing another potentially invasive species will not cause further unforeseen problems to the environment.