An insect has been identified that just might prove to be the holy grail of biological control: a safe predator for Japanese Knotweed.
The Commonwealth Agricultural Bureaux International has announced plans to begin consultation on the use of a Japanese psyllid to attack knotweed in the UK. If approved, this will be the first time an exotic species has been used in Britain to control a plant. Psyllids or jumping plant lice are true bugs, and look rather like aphids. They are small plant-feeding insects that tend to be very host specific, feeding on one (or a very few) plant species. For this reason they could be ideal for biological control. The problem, of course, is that biological control has a terrible reputation for doing more harm than good. Cane toads are perhaps the best known example of this going wrong. The Telegraph has helpfully compiled a list of successes and failures in biological control. Perhaps psyllids will soon be on the list – but in which column?