Past management guides have viewed red pine as a species with fewer insect and disease related concerns than other Lake States conifers. It does not have a major defoliator such as the jack pine budworm that damages older jack pine stands on a regular basis. Nor does it have a major pathogen such as blister rust in white pine that can kill large numbers of trees. Its more common disease problems tend to be subtle, such as periodic outbreaks of shoot blights that kill and deform seedlings and small trees. These epidemics occur infrequently and are often forgotten during the intervening non-epidemic years. Though red pine does not have what many would regard as a single major pest problem, it does have an array of insects and diseases that can, on occasion, cause significant damage.
Mammal caused damage is generally minimal in red pine. Pocket gophers can eat the roots of seedlings and young trees causing extensive damage in isolated plantations in some locations in the Lakes States. Deer browsing is rarely a significant problem on red pine.
Weather events can cause significant damage and can create conditions conducive to widespread disease epidemics. Drought and hail damage both favor outbreaks of Diplodia shoot blight and canker. Persistent wet weather, especially in the spring and early summer often results in Sirococcus shoot blight epidemics, especially in northern parts of Wisconsin and Minnesota, and Michigan’s Upper Peninsula. Damage from heavy snow, ice, and wind is relatively common in dense plantations where trees have developed small crowns.
The most common damaging insects have been associated with seedlings and young stands. As long as older plantations are thinned on a regular cycle of 10-15 years, tree growth and vigor is generally maintained and tree mortality and/or growth loss is minimal.
Several diseases have become widespread because of inadvertent planting of infected nursery stock. The severity of some of these diseases has increased because of environmental and site factors that are favorable for pathogen development and spread.
In the Great Lakes region, red pine largely has been managed in monoculture plantations. Even natural stands are often relatively pure. Any tree species growing in largely pure stands is inherently at risk to outbreaks of insects or diseases. This concern is further compounded with red pine since the species has very limited genetic diversity. Fortunately, no major insect or disease threatens the existing resource at this time, though that could change with the introduction of an exotic species. Managers do have opportunities to develop diversity within existing plantations as well as when establishing new red pine stands. This process should reduce some of the risk associated with largely pure red pine stands.
It is often possible to manage red pine to reduce insect and disease risk and minimize losses. The emphasis should be on long-term strategies that prevent or reduce the risk of pest outbreaks. It is generally easier to prevent problems than it is to deal with an ongoing outbreak.
information on specific
pest problems in red pine
are described and discussed
in the section titled Specific
Pests are described based
upon what part of a tree
they damage. This section
provides links to additional
management guides and
aides. Further pest information
can also be obtained in
a section on Pest
Problems and Stand Development.
This section details
pest problems that are
most likely to occur
during various stages
in the stand development
of red pine.