Emerald Ash Borer Switching Hosts

The Emerald Ash Borer (Agrilus planipennis), an invasive pest once thought to only target ash trees, appears to be able to utilize a wider variety of trees as hosts. A researcher at Wright State University, Professor Don Cipollini, has found that the green beetle will also attack white fringetree, commonly known as Monrovia (Chionanthus virginicus) (Cipollini and Peterson, 2018). Cipollini was examining some white fringetrees in southwestern Ohio and discovered the tell-tale signs of an emerald ash borer: a D-shaped exit hole. This observation makes the white fringetree the second non-ash EAB host. In 2017, EAB was also observed successfully completing development to adulthood on a major cultivar of olive after its cut stems were inoculated with EAB eggs (Cipollini et al., 2017).

A close-up photo of a white fringetree taken in Maryland (Photo credit: Flickr).

A close-up photo of a white fringetree taken in Maryland (Photo credit: Flickr).

In addition to the threat it poses to native Oregon ash (Fraxinus latifolia) and other ash species planted around the state, EAB’s ability to utilize cultivated olive as a host is another reason for Oregonian’s to be concerned. While still fairly young, the olive industry is growing in the state of Oregon.

It is estimated that the emerald ash borer will have caused $10 billion in economic damage by 2019 across the United States. Now that there is a new potential host for the insect, the extent of the issue could be more devastating than previously understood.

Literature Cited
Cipollini, D., C.M. Rigsby, D.L. Peterson. 2017. Feeding and Development of Emerald Ash Borer (Coleoptera: Buprestidae) on Cultivated Olive, Olea europaea. Journal of Economic Entomology: 10(4). 1935-1937. https://doi.org/10.1093/jee/tox139

Cipollini, D. and D.L. Peterson. 2018. The potential for host switching via ecological fitting in the emerald ash borer‐host plant system. Oecologia (2018) 187:507–519. https://doi.org/10.1007/s00442-018-4089-3

Call for 2019 Oregon Invasive Species Council Nominations

The Oregon Invasive Species Council (OISC) is seeking nominations for 5 at-large member seats to serve a 2-year term from 2019-2020. Could you, or someone you know, be a good addition to the Council? Send us your nominations by November 8, 2018!

Many state, federal, and tribal governments, as well as local government agencies and non-governmental organizations, play a role in managing invasive species. In order to successfully protect Oregon from invasive species, the OISC recognizes the need for participation between a wide range of fields and expertise.

Strong nominees will have expertise in one or more of the following areas: environmental law; marine and estuary ecology; aquaculture, horticulture; weed control; small woodlands; parks and recreation; environmental or outdoor education; K-12 education; pet trade; regional industry or representation; and seed or nursery industry. The council is particularly interested in representation outside the Willamette Valley including Coastal, Eastern, Southern, or Central Oregon. Nominees should be willing and able to serve for two years.

For more details on how to submit a nomination, check out the official 2019 OISC Nomination Press Release.

Factors Influencing the Release of Invasive Pets

Science Daily recently published an article on a study that aimed to identify biological and economic factors that influence the release exotic pets. The study, conducted at Rutgers University-New Brunswick by ecologists Julie Lockwood and Oliver Stringham, found that pets that were both prevalent in the pet trade and that were large-bodied or long-lived had the highest probability of being released (Stringham & Lockwood, 2018).

These findings could help provide guidance for educational programs and awareness around the responsibility of owning exotic pets, specifically reptiles and amphibians, and the importance of not releasing them into the wild. To learn more about why you should never release pets into the wild, visit the OISC Don’t Let it Loose webpage.

To read the full article, published by Science Daily on August 22, 2018, click here.


Oliver C. Stringham, Julie L. Lockwood. Pet problems: Biological and economic factors that influence the release of alien reptiles and amphibians by pet owners. Journal of Applied Ecology, 2018; DOI: 10.1111/1365-2664.13237

Pretty Plants Create a Dangerous Threat

Columbia County’s The Chronicle recently published an article about the threat of invasive plants and shared some great insight from Crystlyn Bush, a Riparian Specialist with the Columbia Soil & Water Conservation District. Though this may not be new information to some of us, certain attractive plants or those that provide delicious fruit can be quite dangerous, posing a threat to biodiversity across the country. Specifically in our region, we have issues with Himalayan Blackberry, English Ivy, and Scotch Broom, among others. These plants arrived here by different methods; some came over inadvertently on ships with settlers, while others were intentionally introduced by people who weren’t aware of the long lasting impacts.

These plants not only affect biodiversity, but can have huge economic consequences. “The top 25 invasive plants are responsible for $83 million in costs to agriculture in the form of reduced production, the cost of controlling their spread, and degrading the native environment,” says Bush.

However, Bush gives us hope and a positive outlook on invasives: “There is not a bad plant, just a plant out of place.” While we may not be able to get rid of invasives entirely, we can attempt to keep them from spreading further.

Read the full article written by Morris Malakoff here.

To learn more about invasive plants in Oregon, check out the Oregon Department of Agriculture’s Oregon Noxious Weed Profiles page.


Beech Leaf Disease: Emerging Threat from the Eastern US

There is another forest pest that needs to be on our radar! Beech Leaf Disease (BLD) is a newly recognized problem of American Beech trees (Fagus grandifolia) and possibly European Beech (Fagus sylvatica). It was first observed in northeast Ohio in 2012 and has has since been observed in Pennsylvania, New York, and the Canadian Province of Ontario.

The symptoms of BLD can include striping on leaves, thicker textures where striping occurs, and heavily shriveled and deformed leaves in later stages. BLD can even result in mortality, mainly in saplings, occurring in as little as two years. Larger trees can resist BLD effects longer and some foliage that appear to be unaffected may even persist on an otherwise affected tree. That being said, it has spread rapidly in established areas, with the proportion of American beech showing symptoms reaching nearly 100% (Pogacnik and Macy, 2016).

Early leaf striping symptoms of BLD. From Pogacnik & Macy, 2016.

Early leaf striping symptoms of BLD. From Pogacnik & Macy, 2016.

Later stages of BLD resulting in leathery, curled leaves. From Pogacnik & Macy, 2016.

Later stages of BLD resulting in leathery, curled leaves. From Pogacnik & Macy, 2016.

To address this threat, a group of individuals was gathered earlier this year from various fields and partner agencies with expertise in BLD. The purpose of this group is to create a framework document that will guide future work, hopefully leading to a decline in the disease and the recovery of healthy beech species. You can look for the framework document to be complete by the end of this year from USDA Forest Service Forest Health Protection staff. 


To view/download the BLD Pest Alert, click here.

To view/download the August 2018 BLD Update, click here.


Information in this post was gathered from the BLD Pest Alert, written by John Pogacnik and Tom Macy (2016); August 2018 BLD Update, written by James Jacobs.