Invasive species are attacking the North Country by land as well as by sea.

The emerald ash borer is the latest pest that is looming on the horizon, and it has the potential to devastate North Country forests and city landscapes. First identified in southeastern Michigan in 2002 as the cause of widespread ash-tree decline and mortality, it has now spread to a dozen states as well as Ontario and Quebec.

Tens of millions of ash trees have been killed since the pest's discovery, and infestations have been found as close by as Randolf in the southwestern portion of New York state and 45 miles southwest of Montreal in Quebec.

However, there is a silver lining that may prevent widespread damage if careful vigilance and quick responses are maintained. As a rule, the insect does not fly over long distances if food and a mate can be found nearby. The pest is spread more often by human activity, such as transporting firewood from location to location.

New York passed regulations in 2008 that prohibit untreated firewood from entering the state and limit movement within the state to 50 miles. But with the popularity of camping these days — especially during the recession while many vacationers who might ordinarily stay in hotels are trying to cut back on their expenses — there's ample opportunity for rules to be ignored or for those who haven't gotten the message to inadvertently spread the pest.

Currently, the U.S. Department of Agriculture is overseeing the spread of 2,500 emerald ash borer traps throughout the region to find out if the insects are spreading and identify infestations when they arrive. The purple boxes found in ash trees, placed by such groups as Cornell Cooperative Extension, the Nature Conservancy, the Department of Environmental Conservation and other volunteer groups, can be seen along roadways throughout the North Country.

Rapid-response plans have been put into place to deal with any outbreaks. Sites will be immediately quarantined if an outbreak is discovered.

Meanwhile, there are other things that local residents can do. Besides carefully following the rules about transporting firewood, if anyone sees a purple trap damaged or on the ground, they can call the USDA emerald ash borer hotline at 866-322-4512 to report it.

Or, if you suspect an infestation, you can also call the hotline. Emerald ash borers, barely longer than a fingernail, have metallic green wing covers and a coppery-red or purple abdomen.

Damaged trees quickly suffer a canopy dieback and often have extensive sprouting from the roots or trunk.

The trees may also have extensive woodpecker damage as the birds dig into the trunk in search of emerald ash borer larvae.

It is incumbent on all of us to be vigilant and stop this pest before it inflicts major, irreparable damage on the yards, urban landscapes and forests of the North Country.