Walnut Council Bulletin Promoting Walnut and Other Fine Hardwoods Volume 40, Number 2 ISSN 1041-5769 June 2013

Walnut Council State Chapter Reports Bark and Ambrosia and Their Associated Fungi Colonizing Stressed Walnut in Missouri and Indiana Missouri Chapter Indiana Chapter Report The Missouri Chapter of the Walnut Council had its spring The Indiana Chapter met on April 20th at the Bill By Dr. Sharon Reed and Dr. James English, post-doctoral fellow In addition to walnut twig beetles, there are many other types meeting on Friday and Saturday, May 10 & 11 at member’s Rodecker property in central Indiana with 34 in and professor of the University of Missouri Plant Sciences of bark- and wood-boring beetles that create egg galleries in properties in central Missouri. On Friday, the 32 attendees attendance. The sessions were led by Lenny Farlee Division, Dr. Jennifer Juzwik, forest pathologist of the Forest black walnut trees. Most of these beetles carry fungi on their carpooled to the Fred Crouse property. Management of (Purdue University extension), and Phil O’Connor Service Northern Research Station, and Dr. Matt Ginzel, bodies, some of which can be pathogenic to trees. Researchers mainly white and red oak was discussed along with the past (Indiana Division of Forestry). The 10 year old planting associate professor of the Purdue Department of Entomology at the University of Missouri, Purdue University and the Forest management history and plans for the future. featured over 2,000 walnut trees with some single and Service have teamed up to investigate which bark and ambrosia (TCD) is a growing threat to black double row white pine borders. The site has a gradient beetles attack black walnut in the Midwest and to characterize Then the group visited the Jeremy Wilson property, which walnut, an economically and ecologically important tree in the in soil quality and is scheduled for thinning and pruning the types of fungi that they carry with them. Bark beetles create has been managed intensively for the last few years. The eastern US. Trees in the earliest stages of TCD do not display soon. The trees represent genetic tests of select egg galleries in the inner bark and ambrosia beetles create egg tract had been environmentally harvested and this was symptoms. In later stages, leaves of the canopy become yellow, seedlings versus bed run seedling, sprouted seed from galleries in the wood. These beetles are close relatives of the followed by a timber stand improvement practice. One of wilt, and ultimately die, yet remain attached to their branches. a single improved tree, and a progeny test of walnut walnut twig . Jeremy’s goals for the tract is to manage for high quality Eventually, all branches in the canopy may die, leading to tree showing the effects of diminishing soil quality. Our research team aims to improve TCD detection in the white oak and try to harvest a tree per acre per year. death. He has his own equipment and has harvested the tract During lunch a representative from the American Midwest and elucidate the possible roles of other beetles and TCD is caused by the , morbida that is carried marketing the lower quality trees and removing most of the Chestnut Foundation discussed research being fungi in the disease. Knowing which bark and ambrosia beetles by walnut twig beetles ( juglandis) attracted to pole material, some of which has been sold as firewood. He conducted with chestnut trees, including how to plant attack black walnut in the native range will aid surveyors in walnut trees. After landing on a tree, the beetles bore into the is also trying to sell the remaining small wood and cull logs and grow them. The afternoon session demonstrated differentiating between walnut twig beetle and other . inner bark to create egg galleries. The fungus spreads from for biofuel. pruning, spacing, and decision-making for thinning the Also, knowing which fungi are carried by beetles will determine galleries and creates small bark cankers. When trees are plantation for maximum timber growth. The fall field day if we need to monitor for other beetle species that might carry G. From that point the group drove to Scott Brundage’s attacked by a large number of beetles, the fungal cankers can morbida or other tree pathogens. property. Scott has about 20 acres under a deer proof will be October 5th in Greene County. coalesce and lead to development of the disease (Figure 1). For this investigation of beetles and associated fungi, our team fence (most of the time). He is cooperating with HTIRC on Submitted by Susan Greene a plantation of walnut selections from several states. Each was faced with the question of how to collect enough beetles year the trees are pruned lightly and evaluated for forest, to study. We decided to take advantage of the fact that bark diseases, nut production and growth. Scott also has several and ambrosia beetles are attracted to trees that are stressed thousand pitch/loblolly hybrids growing on the property for and declining in vigor. Consequently, researchers created potential pine straw production. There is also a plantation declining “trap” trees. During 2011, twelve trap-tree locations for nursery stock. were selected in Missouri and fifteen study sites in Indiana. At On Saturday, 44 attendees from Missouri, Minnesota and each location in Missouri, four black walnut trees were girdled Iowa met at the property of Mike and Nancy Gentzsch and treated with glyphosate or picloram to induce decline. At in Callaway County. The morning session involved the each study site in Indiana, two to four black walnut trees were selection, grading and evaluating walnut trees for marketing. stressed by girdling. Trap trees were left standing for three The reasons for leaving a $400 tree and harvesting a months to give beetles time to attack. Afterwards, two 12- inch $50 tree were presented to the group. After the marking Figure 1— Walnut twig beetle egg galleries and long stem and four branch pieces were removed from the trees and grading session was completed, a timber stand coalescing cankers on a walnut branch (Photo by Ned and placed in beetle emergence buckets (Figure 2). improvement segment was conducted. Even though the Tisserat, Colorado State University, bugwood.org) group was mainly in a walnut stand other considerations for the thinning of a stand were discussed including wildlife, Declining walnut trees with TCD symptoms were first described aesthetics, stream bank and flood plain protection and other in the 1900’s in the southwestern US, within the native range Figure 2— Modified 5-gallon buckets used forest species and products. of walnut twig beetle. However, the role of the beetles in tree decline was not known at first and decline was blamed on to collect that After lunch, Mike Gentzsch ran his bandsaw mill and drought. Then in 2009, Colorado scientists made the connection emerged from black explained some of the products he produces. He also between walnut twig beetles, the pathogenic fungus, and walnut logs (Photo by demonstrated his clipper equipment where he can shear declining black walnut trees. Since that time, the walnut twig Sharon Reed, University off smaller trees (under 4 inches in diameter) in a thinning beetle and have been detected outside of of Missouri). or clearing operation. He also had a commercial tractor their native southwestern range, with known occurrences in nine mounted skidder/winch with about 150’ of cable so that he western states and three eastern states, including Tennessee, can winch trees out of a stand with a minimum of damage to Pennsylvania, and Virginia. G. morbida infected trees have also the site and the residual trees. HTIRC select seedling plantation in central Indiana, photo by Jim McKenna, US Forest Service been detected in North Carolina but not the beetle, and walnut Submitted by Fred Crouse, Missouri Chapter secretary twig beetles only have been collected from traps located at an Ohio mill. Continued on page 18 16 www.walnutcouncil.org 17 Walnut Council Bulletin Promoting Walnut and Other Fine Hardwoods Volume 40, Number 2 ISSN 1041-5769 June 2013

Continued from page 17 Bark and Ambrosia Beetles Our emergence bucket traps consisted ambrosia beetle and the fruit-tree who provided oversight, equipment, of a five-gallon plastic bucket with most pin hole borer. The association of vehicles, and research space. Also, we of the bottom cut out with an attached Geosmithia fungi with ambrosia beetles extend thanks to research technicians, funnel and a transparent collection jar. is not unusual and has been described Megan Shawgo of the Missouri Plant Logs were end coated with wax and previously in Europe, Central America, Science Division and Matt Paschen and suspended from the lid of the bucket. and the US. Although G. morbida was Gary Frazier of the Purdue University After adult beetles emerged from logs, not detected, other pathogens were Entomology Department for collecting they were attracted to light emanating commonly associated with sampled wood, rearing and collecting emerged from below the bucket and fell into the beetles. Fusarium solani and multiple insects, sorting beetles and isolating collection container. Our team reduced Phaeoacremonium species were fungi. Another special thanks to MDC Figure 3A and 3B—Trapping sites in Missouri and Indiana. Small, medium, and forest Pathologist Simeon Wright, Walnut the risk of beetles and the fungi on large dots represent 1 to 4; 5 to 8; and 9 or more beetle species, respectively, isolated frequently from beetles. These Council member Harlan Palm, Hardwood their bodies desiccating by placing trapped at each location. Black, blue and green dots represent 1 – 500, 501 – pathogens are known for their ability to Tree Improvement and Regeneration a moistened paper towels in each 1000, and 1001 – 2500 beetles, respectively. Trapping locations with the most attack many species of woody plants, collection cup. including nut- bearing trees that have Center (HTIRC) research scientist Jim species and beetles captured appear as large, green dots while locations with few Figure 4—Top view of More than 16,000 bark and ambrosia species and beetles appear as small, black dots. Figure created by Bill Dijak, US been weakened by drought, flood, and McKenna, HTIRC extension forester saxesenii (left) and Pityophthorus Lenny Farlee, USDA HTIRC forest beetles were collected as they Forest Service. freeze damage. juglandis (right). Photos by Natasha manager Brian Beheler, MU technician emerged from the logs. Each beetle Other than Geosmithia pallida, more Wright, Florida Dept. of Ag. and Consumer the middle of a forest. One reason stem borers will resprout. Young trees Jim Licklider, USFS biological aide Keith was identified based on its body shape than 80 types of fungi were recovered services and Steven Valley, Oregon Dept. for some trap-tree locations having attacked by these species may not Brown and numerous MDC Forestry and its patterns of spines, ridges, and from the bodies of bark and ambrosia of Ag, Bugwood.org, respectively. more beetles than other sites could be appear to be stressed. Tree death and Division employees for assistance in site punctures. On the basis of these traits, beetles. These fungi normally occupy differing amounts of breeding material dieback are thought to be the result of selection and field work. Finally, a thank beetles collected from Missouri and many different such as dead could be easily confused by collectors (nearby dead trees, wood debris) pathogenic fungi introduced to woody and living plant material, soil, insect with limited taxonomic training (Figure 4). you is extended to the George O. White Indiana were sorted into 19 species, State Forest Nursery for donating black available to beetles for egg laying. tissues when beetles create egg guts, and parasitized insects and fungi. In addition, our research team confirmed with 18 of those species collected in galleries. walnut seedlings for testing pathogenicity Indiana and nine collected in Missouri. Most beetles collected in Missouri Most types of fungi occurred on just that all the beetle and species Our team knew that exotic and native of the fungal isolates. Several species of bark-inhabiting and Indiana were species of ambrosia a few beetles; however, some fungal investigated carry a large assortment ambrosia beetles carry many types of types were collected from nearly half or were also collected in our beetles that have been introduced to of fungi on their bodies, including fungi References: fungi on their bodies but no one had more of beetles belonging to a particular Seybold, S., D. Haugen, and A. Graves. study, but are tentatively considered to the United States, and therefore are known to be pathogenic to walnut and described the full diversity of fungi species. These fungal types included closely related tree species. The research 2013. Thousand Cankers Disease be minor or inconsequential to walnut considered “exotic”. Very commonly, exotic beetles arrive on infested wood associated with these beetles. The first Aspergillus, Fusarium, Penicillium,and team is investigating the potential Pest Alert. USDA Forest Service, health. or wood products imported from step in sorting this out was to isolate Phaeoacremonium species. It is uncertain impact of the isolated fungi on black Northeastern Area State and Private No walnut twig beetles were countries worldwide. The small size of fungi from beetles collected from trap- why some types of fungi are associated walnut seedlings, especially their ability Forestry. http://na.fs.fed.us/pubs/ captured at any of the trap-tree these beetles makes them very difficult tree logs. A simple procedure was with beetles more often than others. to cause disease. Further studies are palerts/cankers disease/thousand_ locations. However, a close relative, to detect on imported products during used to isolate fungi from individual The number of fungi found in this survey characterizing lesions, cankers and spots cankers_disease_screen_res.pdf Pityophthorus lautus, was collected at port inspections. The majority of exotic beetles selected from each of the four is likely a conservative estimate of the found on girdled branches of otherwise Tisserat N, W. Cranshaw, D. Leatherman, a single trap tree location in Indiana. beetle species arrive in solid wood most abundant species. Each selected number of fungi carried by beetles. healthy black walnut. C. Utley and K. Alexander. 2009. Black Although not collected in Missouri packing materials from U.S. trading beetle was ground into small pieces One reason for this is that not all fungi This project was funded by US Forest walnut mortality in Colorado caused by during this survey, P. lautus beetles partners in other countries. that were spread onto a nutrient agar are capable of growing on the nutrient Service Forest Health Protection Special the walnut twig beetle and thousand have been collected previously The three most abundant exotic growth medium that supports growth medium used in the study. In addition, Projects. Microbiologist Mark Banik cankers disease. Online. Plant Health throughout Missouri. Fortunately, P. species that were collected from black of G. morbida and many other kinds some fungi go undetected because they and plant pathologist Dr. Dan Lindner, Progress, doi:10.1094/PHP-2009-0811- lautus beetles are not a black walnut walnut included the granulate ambrosia of fungi. Each type of fungus found grow slowly or they are suppressed by USFS, are key cooperators in direct 01-RS. growing on medium was recorded pest and there is no evidence that this beetle (Xylosandrus crassiusculus), combative chemicals produced by other DNA detection of all fungi on a subset of Weber, B.C. and J.E. McPherson and purified. Rather than identifying beetle can transmit G. morbida. the black stem borer (Xylosandrus fungi. A different molecular method, also the assayed beetles. We appreciate the (1985). Relation between attack by each fungus visually using taxonomic germanus), and the fruit-tree pinhole using DNA, is being used by our research assistance of the many other individuals Xylosandrus Germanus (Coleoptera: The number of beetles collected keys, the organisms were identified borer (Xyleborinus saxesenii). These team to detect fungi that otherwise would and organizations that contributed to the Scolytidae) and disease symptoms varied considerably among the trap by molecular methods, using the DNA three beetles are known agricultural not be detected. project. Among these are the Missouri in black walnut. The Canadian tree locations in Missouri and Indiana code unique to each species. (Figure 3A and 3B). For example, pests. In addition, the granulate Our survey demonstrated that stressed Department of Conservation (MDC), Entomologist, 117, pp 1275-1277. Geosmithia morbida was not among researchers collected as few as eight ambrosia beetle and the black stem black walnut trees are an attractive Walnut Council, Purdue University, doi:10.4039/Ent1171278-10. the fungi isolated from 257 beetles; and Indiana private landowners and beetles from a managed plantation borer have been reported to attack for many types of beetles. Author contact: however, a close relative, G. pallida, public land managers. Special thanks but collected over 2,000 beetles from and kill stressed black walnut trees, These beetles are similar in size and Dr. Sharon Reed, [email protected] was recovered from two types of are extended to US Forest Service an abandoned plantation located in regardless of age. In some cases, appearance to the walnut twig beetle and young black walnuts attacked by black ambrosia beetles, the granulate plant physiologist Jerry Van Sambeek 18 www.walnutcouncil.org 19 Walnut Council Bulletin Promoting Walnut and Other Fine Hardwoods Volume 40, Number 2 ISSN 1041-5769 June 2013

Continued from page 17 Bark and Ambrosia Beetles Our emergence bucket traps consisted ambrosia beetle and the fruit-tree who provided oversight, equipment, of a five-gallon plastic bucket with most pin hole borer. The association of vehicles, and research space. Also, we of the bottom cut out with an attached Geosmithia fungi with ambrosia beetles extend thanks to research technicians, funnel and a transparent collection jar. is not unusual and has been described Megan Shawgo of the Missouri Plant Logs were end coated with wax and previously in Europe, Central America, Science Division and Matt Paschen and suspended from the lid of the bucket. and the US. Although G. morbida was Gary Frazier of the Purdue University After adult beetles emerged from logs, not detected, other pathogens were Entomology Department for collecting they were attracted to light emanating commonly associated with sampled wood, rearing and collecting emerged from below the bucket and fell into the beetles. Fusarium solani and multiple insects, sorting beetles and isolating collection container. Our team reduced Phaeoacremonium species were fungi. Another special thanks to MDC Figure 3A and 3B—Trapping sites in Missouri and Indiana. Small, medium, and forest Pathologist Simeon Wright, Walnut the risk of beetles and the fungi on large dots represent 1 to 4; 5 to 8; and 9 or more beetle species, respectively, isolated frequently from beetles. These Council member Harlan Palm, Hardwood their bodies desiccating by placing trapped at each location. Black, blue and green dots represent 1 – 500, 501 – pathogens are known for their ability to Tree Improvement and Regeneration a moistened paper towels in each 1000, and 1001 – 2500 beetles, respectively. Trapping locations with the most attack many species of woody plants, collection cup. including nut- bearing trees that have Center (HTIRC) research scientist Jim species and beetles captured appear as large, green dots while locations with few Figure 4—Top view of Xyleborinus More than 16,000 bark and ambrosia species and beetles appear as small, black dots. Figure created by Bill Dijak, US been weakened by drought, flood, and McKenna, HTIRC extension forester saxesenii (left) and Pityophthorus Lenny Farlee, USDA HTIRC forest beetles were collected as they Forest Service. freeze damage. juglandis (right). Photos by Natasha manager Brian Beheler, MU technician emerged from the logs. Each beetle Other than Geosmithia pallida, more Wright, Florida Dept. of Ag. and Consumer the middle of a forest. One reason stem borers will resprout. Young trees Jim Licklider, USFS biological aide Keith was identified based on its body shape than 80 types of fungi were recovered services and Steven Valley, Oregon Dept. for some trap-tree locations having attacked by these species may not Brown and numerous MDC Forestry and its patterns of spines, ridges, and from the bodies of bark and ambrosia of Ag, Bugwood.org, respectively. more beetles than other sites could be appear to be stressed. Tree death and Division employees for assistance in site punctures. On the basis of these traits, beetles. These fungi normally occupy differing amounts of breeding material dieback are thought to be the result of selection and field work. Finally, a thank beetles collected from Missouri and many different habitats such as dead could be easily confused by collectors (nearby dead trees, wood debris) pathogenic fungi introduced to woody and living plant material, soil, insect with limited taxonomic training (Figure 4). you is extended to the George O. White Indiana were sorted into 19 species, State Forest Nursery for donating black available to beetles for egg laying. tissues when beetles create egg guts, and parasitized insects and fungi. In addition, our research team confirmed with 18 of those species collected in galleries. walnut seedlings for testing pathogenicity Indiana and nine collected in Missouri. Most beetles collected in Missouri Most types of fungi occurred on just that all the beetle and weevil species Our team knew that exotic and native of the fungal isolates. Several species of bark-inhabiting and Indiana were species of ambrosia a few beetles; however, some fungal investigated carry a large assortment ambrosia beetles carry many types of types were collected from nearly half or weevils were also collected in our beetles that have been introduced to of fungi on their bodies, including fungi References: fungi on their bodies but no one had more of beetles belonging to a particular Seybold, S., D. Haugen, and A. Graves. study, but are tentatively considered to the United States, and therefore are known to be pathogenic to walnut and described the full diversity of fungi species. These fungal types included closely related tree species. The research 2013. Thousand Cankers Disease be minor or inconsequential to walnut considered “exotic”. Very commonly, exotic beetles arrive on infested wood associated with these beetles. The first Aspergillus, Fusarium, Penicillium,and team is investigating the potential Pest Alert. USDA Forest Service, health. or wood products imported from step in sorting this out was to isolate Phaeoacremonium species. It is uncertain impact of the isolated fungi on black Northeastern Area State and Private No walnut twig beetles were countries worldwide. The small size of fungi from beetles collected from trap- why some types of fungi are associated walnut seedlings, especially their ability Forestry. http://na.fs.fed.us/pubs/ captured at any of the trap-tree these beetles makes them very difficult tree logs. A simple procedure was with beetles more often than others. to cause disease. Further studies are palerts/cankers disease/thousand_ locations. However, a close relative, to detect on imported products during used to isolate fungi from individual The number of fungi found in this survey characterizing lesions, cankers and spots cankers_disease_screen_res.pdf Pityophthorus lautus, was collected at port inspections. The majority of exotic beetles selected from each of the four is likely a conservative estimate of the found on girdled branches of otherwise Tisserat N, W. Cranshaw, D. Leatherman, a single trap tree location in Indiana. beetle species arrive in solid wood most abundant species. Each selected number of fungi carried by beetles. healthy black walnut. C. Utley and K. Alexander. 2009. Black Although not collected in Missouri packing materials from U.S. trading beetle was ground into small pieces One reason for this is that not all fungi This project was funded by US Forest walnut mortality in Colorado caused by during this survey, P. lautus beetles partners in other countries. that were spread onto a nutrient agar are capable of growing on the nutrient Service Forest Health Protection Special the walnut twig beetle and thousand have been collected previously The three most abundant exotic growth medium that supports growth medium used in the study. In addition, Projects. Microbiologist Mark Banik cankers disease. Online. Plant Health throughout Missouri. Fortunately, P. species that were collected from black of G. morbida and many other kinds some fungi go undetected because they and plant pathologist Dr. Dan Lindner, Progress, doi:10.1094/PHP-2009-0811- lautus beetles are not a black walnut walnut included the granulate ambrosia of fungi. Each type of fungus found grow slowly or they are suppressed by USFS, are key cooperators in direct 01-RS. growing on medium was recorded pest and there is no evidence that this beetle (Xylosandrus crassiusculus), combative chemicals produced by other DNA detection of all fungi on a subset of Weber, B.C. and J.E. McPherson and purified. Rather than identifying beetle can transmit G. morbida. the black stem borer (Xylosandrus fungi. A different molecular method, also the assayed beetles. We appreciate the (1985). Relation between attack by each fungus visually using taxonomic germanus), and the fruit-tree pinhole using DNA, is being used by our research assistance of the many other individuals Xylosandrus Germanus (Coleoptera: The number of beetles collected keys, the organisms were identified borer (Xyleborinus saxesenii). These team to detect fungi that otherwise would and organizations that contributed to the Scolytidae) and disease symptoms varied considerably among the trap by molecular methods, using the DNA three beetles are known agricultural not be detected. project. Among these are the Missouri in black walnut. The Canadian tree locations in Missouri and Indiana code unique to each species. (Figure 3A and 3B). For example, pests. In addition, the granulate Our survey demonstrated that stressed Department of Conservation (MDC), Entomologist, 117, pp 1275-1277. Geosmithia morbida was not among researchers collected as few as eight ambrosia beetle and the black stem black walnut trees are an attractive Walnut Council, Purdue University, doi:10.4039/Ent1171278-10. the fungi isolated from 257 beetles; and Indiana private landowners and beetles from a managed plantation borer have been reported to attack habitat for many types of beetles. Author contact: however, a close relative, G. pallida, public land managers. Special thanks but collected over 2,000 beetles from and kill stressed black walnut trees, These beetles are similar in size and Dr. Sharon Reed, [email protected] was recovered from two types of are extended to US Forest Service an abandoned plantation located in regardless of age. In some cases, appearance to the walnut twig beetle and young black walnuts attacked by black ambrosia beetles, the granulate plant physiologist Jerry Van Sambeek 18 www.walnutcouncil.org 19