Chopping back old man’s beard
‘‘Old man’s beard must go’’ – Botanic Man David Bellamy urged Kiwis 30 years ago to get rid of one of the country’s worst plant pests, but it is still with us.
At least four different methods of eradicating the creeper Clematis vitalba have been tried since then but it has managed to persist despite millions of dollars a year being spent on control.
But now 14 regional councils and the Department of Conservation are pinning their hopes on a gall mite to suck out the plant’s juices and kill it, and have applied to the Environmental Protection Authority (EPA) to introduce the insect.
EPA senior advisor for new organisms Dr Clark Ehlers said testing in Serbia – the home of old man’s beard – had shown the mite should not attack the nine native clematis species.
‘‘Adult gall mites are less than one millimetre long. They do not fly, but disperse on the wind. They attack old man’s beard by sucking out plant juices and creating tumour-like galls on leaves and shoots. This often leads to the death of that part of the plant.’’
Also known as traveller’s joy, the creeper is said to have been introduced into Taihape in the 1920s.
Over the years authorities had tried to get on top of the weed using fungicides as well as biocontrols such as a leaf miner and sawfly.