The Real Culprit of California’s Wildfires

Dave Powell, USDA Forest Service (retired),

Dave Powell, USDA Forest Service (retired),

By: Adam Doklovic, Agribusiness and Applied Economics | Mansfield, Ohio

In the past few years most of California has been in a massive drought, which has created apocalyptic looking wildfires. According to Angela Johnston, a journalist from a local radio station in San Francisco, California has had over 5,000 wildfires this year alone, and it’s not even considered wildfire season yet!

This summer has been extremely difficult in not only preventing wildfires but also containing them. Why have these fires been able to spread so easily? The question should be more focused with whom than of why. Now we ask, who has been the culprit to allow the rapid spread of these wildfires, none other than a beetle that is only 5 millimeters long.

The Western Pine Beetle is native to many parts of the world but here in the United States the beetle has been taking advantage of California’s drought. Just as when a human is dehydrated, he/she becomes susceptible to a greater number of health issues, the same goes for trees. The Western Pine Beetle is a species of bark beetle that can infest trees that are stressed.  When they infest a tree already struggling with dehydration, the tree has little chance to survive and usually ends up dying.

In California alone the Western Pine Beetle is estimated to have killed over 66 million trees. This has created a lot of standing firewood to allow a massive fire spread in a rapid amount of time.

Next time you turn on the news and the media is blaming global warming, or a rogue campfire for a massive forest fire that is engulfing California just remember that there could be other factors at play, even a microscopic beetle.

Adam Doklovic is currently an undergraduate student at Ohio State and experienced the California drought first hand while interning with the USDA in the Bay Area during summer 2016.


Dead trees are fueling California wildfires, but what’s killing the trees? (KALW San Francisco)

This blog post was an assignment for Societal Issues: Pesticides, Alternatives and the Environment (PLNTPTH 4597). The views expressed are those of the author and do not necessarily reflect the views of the class, Department of Plant Pathology or the instructor.


Thousand Cankers Disease Hits Ohio

Curtis Utley, CSUE,

Image: Curtis Utley, CSUE,

by Stephen Marinkov, Communications major

Being from Ohio it is important for the natives to be educated on invasive species that can harm the state.  Thousand Cankers Disease is an invasive species caused by the fungus Geosmithia morbida.  The fungus is carried by the walnut twig beetle that bores into the trees, killing walnut and butternut trees in Ohio.

This fungus causes thousands of small cankers to form under the bark of the tree; the cankers eventually close up.  When this happens, nutrients and water intended for the branches and stem are cut off, killing the trees.
The Black walnut and butternut trees are most susceptible to the disease and natives should be informed of the symptoms.  Homeowners (?) should be aware of yellowing foliage where the leaves turn yellow and thinning in the upper crown of the infested tree.

Major spread of this disease is caused by human movement of wood products.  Natives need to be aware of the infected trees and limit the movement of potential infected trees.  The Great Lakes Early Detection Network (GLEDN) smart phone app is available as a free download.  This app contains images of Thousand Cankers Disease that users can look at to investigate possible infected trees.

As an Ohio native I want to spread awareness about invasive species that could harm this state.  If natives work together and combat diseases head on we can limit the deaths of so many trees.

More info > Ohioline Thousand Cankers Fact Sheet

This blog post was an assignment for  Societal Issues: Pesticides, Alternatives and the Environment (PLNTPTH 4597). The views expressed are those of the author and do not necessarily reflect the views of the class, Department of Plant Pathology or the instructor.

Sudden Oak Death Kills More Than Oaks

Photo: U.S. Forest Service

Sudden oak death is a disease of oaks and over 100 other trees, shrubs and ornamentals. Photo: U.S. Forest Service

It’s a bit misleading. Sudden oak death is indeed a serious disease of several oak species, but the disease also impacts over 100 trees, shrubs and ornamentals, making it a concern for our forests, landscapes and the ornamental and nursery industries > More info

Sudden oak is an invasive disease spreading in Northern California forests (and a small portion of Oregon), causing widespread death of infected trees.  Because the pathogen, Phytophthora ramorum, infects several ornamental species, nursery stock in California, Oregon and Washington are subject to regulations for dissemination and sale.

It’s not hard to imagine the consequences if sudden oak death were to spread acroo\ss the U.S.  There are very few management or treatment options that are environmentally safe, practical and effective in forest situations.  Ohio State scientists are studying how to determine how many and which trees are likely to survive in a given areas, based on genetic markers.

The work is being conducted by Pierluigi Bonello, professor in the Department of Plant Pathology at Ohio State, Anna Conrad, graduate student, and their colleagues.  Their work was recently published in Forest Ecology and Management (312:154-160).

Read more about their work in a recent CFAES news release > Will It Live or Die?