January 14, 2015

This collaborative effort of the USDA Forest Service Northeastern Area, Missouri Department of Conservation, and Indiana, Iowa and Illinois Departments of Natural Resources provides technical updates on forest health issues of regional interest.Useful information can also be found in previous editions, which are available on the www at

Welcome to a new calendar year! Our goal for this communication is twice per year. It has been a long stretch of time since the last edition of the CSFHW, so we’re giving you TWO feature topics this time. As always, if you think of topics you’d like to hear (or share!) more about, let us know so that we can include information in future editions.

Contents:

Important Regional Forest Health Issues (EAB, ALB, Gypsy Moth, andTCD)………………. Page 1

Weather Overview…………………………………………..…………………………………… Page 6

What Else is Being Reported around the Region …..….………………………………….…….Page 8

Other Issues outside the Region ………………………………………………………………… Page 8

Other Resources and Sources of Information ……………………………………………….. Page 9

Feature Topics:

Investigation of Rapid White Oak Mortality in Missouri, Iowa and Arkansas …..Page9

Apps for Foresters ……………………………………………………………………..Page 11

Important Regional Forest Health Issues

Nonnative insects and pathogens continue to be highly significant forest health issues in our region.In this edition you will find updates on emerald ash borer, gypsy moth, Asian longhorned beetle, and thousand cankers disease.

Emerald Ash Borer (EAB)

All four of the Central States (Missouri, Illinois, Indiana, and Iowa) are now wholly included in one large federal quarantine area.Even when a State is fully under federal quarantine, individual states, such as Illinois and Indiana, have separate state quarantine boundaries in place to try to slow the movement of EAB to counties that are currently unaffected.

Illinois:The internal quarantine now encompasses 61 of Illinois’ 102 counties. EAB was confirmed in 14 new Illinois counties in 2014, including 8 within the quarantine boundaries that were confirmed via EAB traps. In addition, five that are located outside of the current state quarantine boundary were added. Twelve new counties were added to the internal state quarantine in 2014, including seven counties where EAB was first identified in 2014, and five “at risk” counties. For more information on EAB in Illinois, visit the Illinois Department of Agriculture’s EAB page at

Indiana:As of January 6, only eight counties in the SW corner of Indiana are not yet under the internal quarantine. For information on quarantine and reporting EAB in Indiana, see the Indiana DNR webpage at information on how to respond to EAB for your management situation, see the Purdue University EAB page at:

Iowa:Eighteen Iowa counties now have confirmed EAB infestations. Most recently, EAB was confirmed killing ash trees in woodlands in southern Iowa counties.A statewide quarantine, issued in 2014, restricts the movement of hardwood firewood, ash logs, wood chips and ash tree nursery stock out of Iowa into non-quarantined areas of other states. Iowans are urged to be vigilant in reporting suspicious symptoms in counties that are not yet known to be infested.

Missouri:EAB was found in 2 more counties in 2014, bringing the total to 11. EAB populations are growing in the Kansas City area, and have been confirmed in both Kansas and Missouri.The City of Kansas City, MO, manages an aggressive response to EAB ( was also first reported in the St. Louis area in May 2014. For more information about EAB in Missouri see Efforts continued this year to establish biological controls for EAB, with releases of stingless parasitic wasps in Platte County. Releases also occurred in Wayne County in 2012 and 2013.More information about EAB biological control is available at:

We urge people to be vigilant in reporting suspicious symptoms in counties that are not yet known to be infested by EAB, because awareness of the presence of EAB signals a need for landowners to adjust their management from preemptive to responsive activities.Preemptive strategies would include survey and diversification of tree species. Responsive activities would include protective injections with insecticides and salvage harvests.If a landowner is interested in protecting a valuable and healthy ash tree within 15 miles of a known infestation, the next window for preventive treatment measures (trunk injection, soil injection, soil drench, or basal trunk sprays) will open early spring 2015 (mid-April to mid-May).

Woodpecker-flecking is a highly visible indicator of insect presence. If you are seeing a lot of woodpecker activity (e.g. the bark pecked off sections of the stem) in the upper crowns of ash trees, it warrants a closer look to see if EAB is present.

Even when a county or State is under quarantine, it does not necessarily mean that the entire area is infested by EAB. Movement of infested material can enhance the dispersal of EAB, as our vehicles can carry these pests much farther and faster than they disperse on their own.Avoid transporting firewood across county or state lines,since the movement of firewood throughout your own or to other states poses a threat to quickly spread EAB and other plant pests.

One recent twist of EAB events was the discovery by Don Cipollini, a professor at Wright State University in Ohio, of EAB attacking white fringetree (Chionanthus virginicus). The populations of EAB on ash were high at all four locations where this has been observed so far. White fringetree is a small tree native to the southeastern US. Like ash, it is a member of the olive (Oleaceae) family. (source:

Asian Longhorned Beetle in Bethel, Ohio

The number of infested trees in the Clermont County (Ohio) infestation continues to increase. For 2014 (ending Dec 13), 4,617 infested trees have been found, a significant increase from the 1,660 infested trees found during 2013. The grand total is 15,533 infested trees since 2011. The good news is that the quarantine area has not expanded this year – still at 61 square miles.High-risk host trees are being removed (23,996 during 2014) or injected with an insecticide (13,173 during 2014). Eradication is still the goal.

Early detection of a new ALB infestation is important to quickly contain and reduce the loss of infested trees during the eradication efforts. Now (with leaf off) is a good time to have a quick look at the upper canopy of maple trees for signs of ALB (e.g. large exit holes). Another check in July/August for adult beetles is also recommended.

Gypsy Moth (GM) Activities – Summer 2014 treatments, trap catches

We continue to have three levels of gypsy moth treatment activity in our Central States:

  • In areas without known populations of gypsy moth, detection traps are placed in strategic locations, and if trapping results detect an area of concern, delimit traps are placed the following year.If an outlying population is detected, eradication treatments will be applied to try to extirpate that population.Missouri falls in this category, as occasional male moths are captured.
  • In areas with high levels of established gypsy moth, generally the only activity is some suppression treatment to try to minimize the impact of defoliation. This is the situation in parts of northeast Illinois where gypsy moth has been present for some time.
  • The area in between is the “Slow the Spread” (STS) zone, where reducing the numbers of moths in strategic “hot spots” can significantly slow the natural expansion of gypsy moth. An intensive grid of traps helps define the location of these building gypsy moth populations, and the data from the traps is used to define the “Action Zone boundaries”, as shown on the map below.In 2014, Central States in which STS treatments took place were Indiana and Illinois.

The extremely low temperatures in winter 2013-14 may have affected the overwintering population of gypsy moth in the northern Midwest (e.g. Minnesota and Wisconsin, perhaps even Iowa); however, Indiana’s 2014 moth catch does not indicate that any effects on gypsy moth survival extended down to the southern extent of our populations.

The following map also shows the relative moth catches in traps in 2014, with brighter pink/magenta indicating high numbers of moths, and bluish tones indicating building populations. The 2014 Action Zone and Treatments are also shown on the map. The 2014 moth catch numbers was used to define the 2015 Action Zone (not shown on the map), which has shifted very little since 2014.Based on 2014 trapping results, STS treatments for 2015 are being proposed in the Central States of Illinois and Indiana.Forcustomized maps and details on past and proposed STS treatments, visit the STS Decision Support website at

Additional state-specific information on 2014 treatments is in the table.

States without established populations:
Treatment Activities / Trapping Activities
Iowa / No STS treatments were needed for 2014. Also no STS treatments are planned for 2015 due to the low trap catch during 2014. / Gypsy moth detection traps are placed across the State in a joint effort by state and federal agencies. Iowa captured only 46 male moths during 2014, which is lower than the 269 male moths from last year, & 225 male moths in 2012
Missouri / No gypsy moth populations are known to be established in Missouri. / A total of 7,702 pheromone traps were monitored in 62 counties in 2014 through a cooperative effort of state and federal agencies. A total of four male moths were captured statewide in the annual survey (3 in St. Louis Co., and 1 in Camden Co.). Annual traps catches have been less than 10 moths since 2009.
States with established populations:
Treatment Activities / Trapping Activities
Illinois / STS treatments during 2014 consisted of 9 mating disruption sites (approximately 26,000 acres). For 2015, 5 treatment areas proposed, totaling about 10,000 acres (~2500 Btk, ~7500 mating disruption). Due to STS work and weather, the range of gypsy moth has contracted each year over the last few years. / For 2014, IL Department of Agriculture and APHIS placed 9,073 traps and caught 5,223 moths. This is a small decrease from 5,453 in 2013.
Indiana / STS treatments during 2014 included 3 Btk sites (1182 acres) and 2 Mating Disruption sites (10,718 acres). Also 1 eradication site in West Lafayette was treated with Btk (29 acres) and Mating Disruption (750 acres). The STS Project has held the average spread rate to -0.6 miles/yr over the last 4 years. / Trapping continued in the STS area and the uninfested area of the state, with 11,427 traps set & 22,875 moths caught, which is almost double the moths caught during 2013. STS treatment sites and acres for 2015 will be greater than in 2014, but no eradication sites.

Thousand Cankers Disease of Black Walnut

National update, from FHTET Pest Portal*:

Thousand cankers disease (TCD) results from the combined activity of the walnut twig beetle (WTB), (Pityophthorus juglandis) tunneling through the bark and delivering a canker-causing fungus (Geosmithia morbida) which can cause mortality, primarily in eastern black walnut (Juglans nigra).Eastern black walnut is an economically important hardwood species.

On October 8, 2014, the Maryland Department of Agriculture announced the confirmation of TCD on black walnut in Cecil County, Maryland.Two bait logs from one positive trap site collected on September 4, 2014, were confirmed positive by Jennifer Juzwik of the U.S. Forest Service on October 6, 2014.Follow-up DNA sequencing confirmed identity of isolates obtained from beetles in the galleries of two logs. In 2014, two additional counties (Chester and Lancaster) in Pennsylvania were also confirmed to have TCD, and the quarantine was extended to include six counties.

The new MD finding brings the total number of states with confirmed with TCD to 16: Arkansas, California, Colorado, Idaho, Indiana, Maryland, North Carolina, New Mexico, Nevada, Ohio, Oregon, Pennsylvania, Tennessee, Utah, Virginia, and Washington. There are currently 16 states with phytosanitary quarantines in place, six of which are both internal and external regulations.States with external quarantines include: Arkansas, Illinois, Kansas, Michigan, Minnesota, Missouri, Nebraska, Oklahoma, Wisconsin, and West Virginia. States with both internal and external quarantines include: Indiana, North Carolina, Ohio, Pennsylvania, Tennessee, and Virginia.Annual TCD Surveys are wrapping up for 2014, in the eastern US, as the dispersal season comes to a close.

At the end of 2013, TCD was reported for the first time in Italy on a small number of J. nigra trees. This disease may present a risk since walnut (Juglans spp.) is widely grown in Europe.The European and Mediterranean Plant Protection Organization (EPPO) Secretariat decided to add G. morbida and its vector, P. juglandis, to the EPPO Alert List.

* This update was originally written October 24, 2014, by Dr. Bruce Moltzan of the USDA Forest Service. Dr. Jennifer Juzwik and Manfred Mielke provided supplemental information in January 2015. To find current updates on other pests of national importance, visit the FHTET Pest Portal at

What’s up with TCD in the Central States:

In the eastern US, TCD has now been found in six states, plus the pathogen has been found (without WTB) in Indiana. Infestations discovered in the East generally have been present for many years prior to discovery, and they are limited in distribution. TCD isn’t racing across the landscape like EAB, but we are still very intentional in our efforts to determine where TCD is present. In 2014, all four Central States again conducted surveys to detect existing infestations, and none were found.

Most detection efforts for TCD are based either on visual surveys for symptomatic walnut trees or pheromone traps using a lure for WTB. A trap tree survey, in which black walnut trees were intentionally stressed in order to attract beetles, was conducted across 27 sites in Indiana and Missouri in 2011. No WTB were detected in these stressed trees, but many other bark beetles, ambrosia beetles, and weevils were captured and identified. A subset of the captured insects was assayed for Geosmithia morbida. DNA of G. morbida was detected on three specimens of a weevil, Stenomimus pallidus, from a study site in Brown County, IN. This study by Dr. Jennifer Juzwik and others will be published in Plant Health Progress (an e- journal of the Plant Management Network)in January 2015.

In response to this finding of G. morbida, additional specimens of S. pallidus from other study sites in Indiana were assayed, as well as additional ambrosia beetle specimens from the Brown County site. No other beetles yielded the pathogen. The nearest known location of TCD to this Brown County, IN, site is Butler County, OH, approximately 100 miles away. The plantation in Yellowwood State Forest was placed under quarantine and additional surveys are being conducted.

This study was the first report of G. morbidafrom an insect other than WTB. The low frequency of occurrence of the pathogen on S. pallidus suggests a casual (not dependent) relationship, compared to studies where G. morbida has been detected on 100% of WTB emerging from symptomatic trees. The initial interpretations of this study, based on the behavior and characteristics of S. pallidus, is that this particular weevil is unlikely to be capable of causing mass inoculation needed for TCD development.

In another recently released study on G. morbida ( Dr. Keith Woeste and other researchers analyzed the genetic diversity of the pathogen from populations across the US. They confirmed that G. morbida is native to the US, and that the disease likely originated in Southern California. They found the pathogen to be highly variable, indicating it may have high capacity to mutate and evolve.

A third piece of recent TCD literature, an open access article in Forest Pathology ( by Dr. Gary Griffin, documents the development of TCD on diseased black walnut trees in Knoxville, TN, and Richmond, VA, over a period of three years. They found only moderate to quiescent (stable) disease progression on most individual affected trees over a 3-year period, and that the most accelerated disease progression occurred under conditions of low precipitation and low soil moisture. Their observations so far suggest that abiotic stressors (extreme weather, poor site conditions,etc.) may be necessary to initiate TCD symptoms, and that under good growing conditions, affected eastern black walnut trees may exhibit recovery.

These various studies and observations underscore how many aspects of TCD are really not yet fully understood. As we continue to gather information, it is prudent for us to be cautious when we move around plant material (logs, wood burls, and firewood) that might contain the potential pathogen and insect(s) that can cause TCD, and to do our best to manage our walnut resource for health and diversity.

Weather Overview

In the ongoing saga of weather effects on trees, our December 2013 edition left you with trees going into dormancy under moisture stress. At that point in time, we were blissfully unaware that we were about to plunge into the “polar vortex”, which allowed frigid air to reach down into the central plains in December 2013 and then again during January to April 2014. The extended cold led to speculation about the effects of cold on overwintering survival of EAB, but it is worth noting that although the bitter cold may have reduced EAB populations in the far north, these effects did not extend down into the Central States.

The long, cold winter of 2013-14 did eventually give way to summer. In the Central States this summer was cooler than average, generally with adequate moisture. It was a good year for plant growth, and also a good year for fungal growth, allowing leaf diseases to thrive.