Module 15: Pests of the Acadian Forest

Lesson 2 Softwood Pests

Lesson Two explains  what to look for if insects are feeding on softwood trees on your woodland. This will help you narrow down which insect may be feeding there. If a hardwood species is being damaged on your land, skip to Lesson Three for the same kind of process for hardwoods. A few  insects will feed on both kinds of trees.

This lesson begins with what to look for on your woodland in terms of insect damage.  This may be what first catches your attention while walking through a softwood stand on your woodland or on an individual tree. You may notice some changes from a distance and others close up. Next, the lesson examines in more detail what activity you may find on various parts of the softwood tree.








What to look for

When softwood damage is widespread, it can be quite noticeable from a distance. Anyone travelling in some regions of Nova Scotia in recent years has likely noticed bands of greyish brown dead softwoods trees along  the hillsides.  One common cause is spruce beetle which prefers mature white spruce and also attacks other species of spruce.

Walking in your woodland, you may notice changes in your softwood trees. The crowns may have thinned so you can now see through them. There may be dead trees with brown needles. The needles may be off colour - yellow or reddish - instead of green. Perhaps branches are beginning  to droop.

Up close you may notice further signs of damage. On the bark, you may see globs of pitch called pitch tubes that ooze out of holes bored by insects. Other signs include missing needles, dead buds, and clumped twigs or needles. Insects can also create tents or webbing in the branches.

Sometimes you may see the insect itself such as a caterpillar,  feeding on the tree. Insects usually begin feeding in the spring. Make a note of when you first noticed the damage.  If it was in June for example, you may find considerably more damage a month later.





Insect types found on five softwood tree parts

In this section, the tree is studied even more closely. In the chart below, a tree is divided into five parts. Reading down they are: Buds and Shoots, Foliage (Needles), Twig and Branch, Stem or Log, and Root. Reading across the table is the damage you may see, the pest type found feeding there and a few examples. Some pests feed on more than one part of the tree. All these hungry insects are busy boring, chewing, and sucking. This results in certain kinds of visible damage that point in turn to specific insects.


Some Control Options

The insect types mentioned above impact the trees in a woodland to varying  degrees. For many,  the degree of damage may be determined simply by the weather during a particular year. The added stress of a summer drought, wet spring or harsh winter can intensify the impact of a usually  less harmful  pest outbreak.

Some pests may be considered more of a visual problem such as galled and deformed needles or the odd stem killed by a web spinning sawfly which can look unattractive. In forested settings, there may be no need for control options for such pests. However, if your business is Christmas trees, an attractive product is your bread and butter and such pests become a more important issue.

For defoliators, control is often necessary when populations get high enough. Knowing what products to use in a specific situation is key to protecting the resource. Chemical or biological insecticides may not be effective if the pest bores into trees, lives in a ball of spittle or mines into needles. Certain products may work very well on moth larvae, such the biological insecticide Btk, but are completely useless on wasp or beetle larvae.

New products include viruses developed specifically to target particular  species, chemical  mating  disruptors and various lures and attractants.

Knowing what control products are available and when, how and if to apply them are key in protecting your woodland. Remember to read and follow the instructions on the label when using any control agent. Proper application  and use of recommended personal protective equipment are essential for the safe use and effectiveness of any pesticide.


Taking a closer look at the damage to trees on your woodland is the first step to identifying  the pest. The tree part and the type of damage are both initial clues. If you decide that a control product is needed, take time to review and select the appropriate option