Forest Insect & Disease Newsletter

photo collage forest tent caterpillar, person cleaning boot at boot brush station, close up of pine seedling in shock, pine truck with white speaks

July 2021

group of forest tent caterpillars

Oak wilt reaches new territory

When a resident of the Brainerd Lakes Area noticed a group of their beautiful pin oak trees abruptly losing leaves last summer, they became worried.

Read about the latest discovery of oak wilt in Crow Wing County.

drought mpa of minnesota. detail in article.

How dry we are!

According to the U. S. Drought Monitor, at least 40 percent of the state is in Severe Drought conditions, 53 percent of the state is in Moderate Drought conditions and 7 percent of the state is in Abnormally Dry conditions.

Read more about how dry weather is affecting the state.

shriveled brown oak leaves

Shriveling and browning oak and ash leaves? No need to worry.

Our recent complaints of hot, arid weather make us forget that in late May, most northern Minnesotans experienced nighttime temperatures in the 20s.

Read more how cold temperatures caused extensive damage to bur oak and ash.

close up showing tiny white thrips

Small pest with a big impact.

In late May, a retired DNR employee in central Minnesota expressed concern for his sickly basswoods.

Learn how a single report from an observant citizen signaled a widespread pest issue in our forests.

group of forest tent caterpillars

Which is it – forest tent caterpillar, eastern tent caterpillar, or gypsy moth?

How can you tell a forest tent caterpillar from its look-alikes? There are two other species in Minnesota that look similar to forest tent caterpillar and are also active at this time of year.

Learn how to tell them apart.

small purplish-brown colored insect on pine needles.

A native insect may be on the rise in northern Minnesota.

Pine leaf adelgid has not been around much in the last 30 to 40 years and is damaging white pines.

See what this tiny insect is up to.

white colored mold worts on small ash tree trunk.

Those warts on tree branches are not as concerning as they look.

Foresters and landowners in Itasca and St. Louis counties, and most likely others, have observed an abundance of scales on broadleaf trees, particularly small ash trees.

Learn more about what these scale insects are.

comparison between male and female Asian Longhorned beetle and Whitespotted Pine Sawyer.

Mistaken identity? Never again!

Whitespotted sawyer is a longhorned beetle native to Minnesota and often mistaken for the invasive Asian longhorned beetle.

Learn how to tell them apart.

Hackberry emperor butterfly on the ground

A bevy of butterflies!

Massive emergence of native hackberry emperor butterflies in one homeowner's yard led to a call to the DNR's forest entomologist.

Read more about this wonderful massive emergence of butterflies.

pine forest

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