White pine weevil attacked and killed the terminal leader on a young white pine. / Photo Credit: Wisconsin DNR

By Linda Williams, DNR Forest Health Specialist, Woodruff
Linda.Williams@wisconsin.gov,  920-360-0665

 Symptoms of white pine weevil attack are easily detected at this time of year, as damaged leaders turn dark brown and branch tips can curl or droop.

White pine weevil (Pissodes strobi) is a native insect that can attack and kill the terminal leader of white pine, jack pine and spruce. Another common name for this insect is “tip weevil.”

These insects prefer to attack stout terminal leaders.

When the terminal leader dies, lateral branches often compete to take over apical dominance, but this can leave a noticeable crook in the main stem for decades. If two or more lateral branches take over, forking can occur.

New terminal leaders may be attacked in subsequent years, causing an additional crook or forking.

For additional information, preventative forest management and control options, check out this article from 2023.

White pine weevil attacks are to be expected in a percentage of young open grown white pine each year. / Photo Credit: Wisconsin DNR

In a case of white pine weevil infestation, lateral branches will take over apical dominance when the terminal leader is killed. Forks can be formed when more than one branch takes over. / Photo Credit: Wisconsin DNR