(EDITOR’S NOTE: This is one in a series of articles on the continuing spread of pine wilt disease.)

Kansas Forest Service District Forester Jim Strine was in the Barton County area this week to help continue education into a serious disease that is decimating non-native pine trees as it spread across the nation.
When Strine met with the Barton County Commission this week, he explained that pine wilt has spread in Kansas at least as far west as Rush, Ellis, Rooks and Phillips counties, and it will eventually cause the loss of introduced pines.
Since those make up about 95 percent of all pines in the state, the loss will be serious.
Once pine wilt gets established in a community the only answer it to control it, keep it from spreading as well as possible. There is no cure, Strine told the commissioners.
According to information from the Kansas Department of Agriculture, the disease is devastating to the introduced pine species, which have proven popular for decades in residential areas, because they are so hearty in other ways.
“Symptoms of pine wilt begin to occur in mid summer and continue into early winter in Kansas.
“During feeding by the adult pine sawyer (a type of beetle) after emergence in late April and May, the nematodes leave the respiratory system of the beetle and enter the wound tissue.
“There the nematodes transform into adults and invade the sapwood primarily feeding on resin canals.
“The nematodes reproduce rapidly with each generation taking only five to six days to complete.
“In four to six weeks following feeding, the nematode is systemic through the tree and symptoms begin to develop.”
The affects of this disease are easy to spot, according to the information from the agriculture department.
“At first the infected tree begins to wilt and needles turn a dull green.
“If conditions are hot and dry, the tree rapidly dies with needles turning brown and no resin flow. Some trees die slowly up to three months of infection if conditions are not stressful. Pine sawyers continue to emerge from infected wood through the summer months resulting in new infection of nearby trees over the summer and into the fall.
“Overall, symptoms include flagging of branches, wilting of needles, absence of resin in branches, and rapid death of the tree.”
Pine species that are at risk, commonly found in Kansas, include the Scots, Austrian, Japanese Black, white pine, and loblolly pines. “Scots and Japanese Black pines are considered highly susceptible to the nematode,” according to the department of agriculture.
The department of agriculture information notes that this disease continues to move through the state.