Visit to Manitoba, Canada
I spent the whole of September 2014 visiting Winnipeg in Canada where there is a successful Elm Control Programme that in many ways mirrors that of Brighton and Hove’s internationally own renown programme to combat Elm Disease.
Winnipeg in Manitoba, Canada and its surrounding towns have a massive reliance on Elm in the landscape, again mirroring our own dependency in Brighton and Hove on the species. However the thousands of naturally growing Elm trees I viewed recently in superb tree lined streets are Ulmus americana and these while coping with the area’s extremes of climate make a stunning contribution to the street scenes. Another noticeable fact is that the trees are not subjected to frequent pruning as occurs locally, this due to the fact that summers are extremely hot on the prairies and the shade offered by these trees brings welcome relief to households, quite the opposite from the complaints of shading Arboriculturists experience locally with street situated trees. If temperatures continue to rise it is quite possible that this view may change dramatically and the term ‘Shade Trees’ becomes a more frequent phrase whereas it has been for some considerable time in Canada and the USA.
Winnipeg in Manitoba, Canada and its surrounding towns have a massive reliance on Elm in the landscape, again mirroring our own dependency in Brighton and Hove on the species. However the thousands of naturally growing Elm trees I viewed recently in superb tree lined streets are Ulmus americana and these while coping with the area’s extremes of climate make a stunning contribution to the street scenes. Another noticeable fact is that the trees are not subjected to frequent pruning as occurs locally, this due to the fact that summers are extremely hot on the prairies and the shade offered by these trees brings welcome relief to households, quite the opposite from the complaints of shading Arboriculturists experience locally with street situated trees. If temperatures continue to rise it is quite possible that this view may change dramatically and the term ‘Shade Trees’ becomes a more frequent phrase whereas it has been for some considerable time in Canada and the USA.
While the City’s main insect carriers of the disease are Scolytus scolytus, the large European bark beetle and to a lesser degree Scolytus multistriatus, the small European bark \beetle, Cities and towns in Manitoba face spread of the Elm Disease fungi by three separate vectors, Scolytus multistriatus, the Small European Elm Bark Beetle, Scolytus schevyrewi, the Asian Elm Bark Beetle and Hylurgopinus rufipes, the Native Elm Bark Beetle (Canada).
The Asian Elm Bark Beetle, S. schevyrewi was first positively identified in 2003 although it is considered to have been present since at least the early nineties and along with S. multistriatus performs similar to most Scolytids beetles in the infection process. Hylurgopinus rufipes, The banded Bark Beetle and Canada’s native bark beetle has a quite different mode of behaviour in that it will move down an Elms trunk and colonise the bark near to the base of the tree. This habit allows the local City Foresters to place chemical bands around trees trunks as a relatively inexpensive practical barrier to prohibit beetle movement. Alongside this to combat overwintering beetles the Local Authorities conduct a pesticide control programme targeting the bottom half metre of all Elms on public and privately owned land with private owners having the right to refuse if they so wish.
The accompanying public notice was issued for Arborg a farming town north of Winnipeg but is similar to those issued throughout the region. It has long been well known that infected timber containing beetles or their larvae presents a major threat to any new storage area if transported from its original site. In areas around Winnipeg the risks are made clear by the erection of roadside signs warning of the problems associated with such movement. The illustrations show such signs on the highway into Portage la prairie, Manitoba.
The Asian Elm Bark Beetle, S. schevyrewi was first positively identified in 2003 although it is considered to have been present since at least the early nineties and along with S. multistriatus performs similar to most Scolytids beetles in the infection process. Hylurgopinus rufipes, The banded Bark Beetle and Canada’s native bark beetle has a quite different mode of behaviour in that it will move down an Elms trunk and colonise the bark near to the base of the tree. This habit allows the local City Foresters to place chemical bands around trees trunks as a relatively inexpensive practical barrier to prohibit beetle movement. Alongside this to combat overwintering beetles the Local Authorities conduct a pesticide control programme targeting the bottom half metre of all Elms on public and privately owned land with private owners having the right to refuse if they so wish.
The accompanying public notice was issued for Arborg a farming town north of Winnipeg but is similar to those issued throughout the region. It has long been well known that infected timber containing beetles or their larvae presents a major threat to any new storage area if transported from its original site. In areas around Winnipeg the risks are made clear by the erection of roadside signs warning of the problems associated with such movement. The illustrations show such signs on the highway into Portage la prairie, Manitoba.
