and R.G. Western Forest Insects and Diseases: Publications and Links, Forest Insect and Disease Leaflets - Balsam Woolly Adelgid, How to Cite DecAID | Frequently Asked Questions | Further Help and Website Contact, View Maps by WHT, plot, S-Class, and SVS diagrams, Guide to the use and interpretation of DecAID, http://www.biodiversitylibrary.org/bibliography/80321, http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0165094, http://www.fs.usda.gov/Internet/FSE_DOCUMENTS/fsbdev2_043667.pdf, Willamette Valley, Puget Sound trough, coastal streams, South of the Cowlitz River in Washington, in the Cascade Mountains and Coast Range. USDA Forest Service, Pacific Northwest Forest and Range Exp. Repeated attacks weaken trees, cause twig gouting, kill branches and, over the course of several years, cause trees to die. Balsam woolly adelgid is similar to these species: Hemlock woolly adelgid, Pineapple gall adelgid, Adelges and more. Balsam woolly adelgid, Adelges piceae, (Ratzeburg) (Hemiptera: Adelgidae) BWA was introduced into eastern North America from Europe around 1900. Symptoms of balsam woolly adelgid feeding is more likely to be noticed. Increased deadfall increases fuel loads and may heighten the potential for severe wildfires. Dense red rings similar to compression wood are formed in the wood at feeding sites in the bole, and gall-like structures and calluses form on branches and twigs. While wildfires can be regenerative for many forests, they are hazardous in the Central Wasatch because of the proximity of our forests to urban areas. BWA infestations primarily target true fir trees, with subalpine fir being the most susceptible species. It feeds on true firs, including balsam and Fraser firs. Generally speaking, balsam woolly adelgid appears to be established throughout much of the range of true firs in Oregon and Washington. Tiny (1-2 mm) white cottony tufts on the bole or branches that indicate the presence of adult adelgids usually are most easily found in the spring and late fall. Liz Hebertson, a U.S. Forest Service Forest Health Specialist in the Uinta-Wasatch-Cache National Forest, says that the cold temperatures throughout fall and winter greatly reduce the risk of spreading BWA, and that there isn’t enough of a risk to take immediate action yet. (2016) for subalpine fir and grand fir may be useful for assessing stand level-impacts of balsam woolly adelgid and the likelihood of adverse effects. Because the balsam woolly adelgid is a non-native, introduced species, it would be highly undesirable to encourage its activity in native ecosystems. Figure 5. Over time, natural selection pressures in host species populations will probably increase levels of tolerance and resistance to this insect. Your email address will not be published. 62(2): 181–189. 2indicates an appropriate time to consider management options, such as chemical treatments and movement restrictions. Goheen, E.M. and E.A. Balsam woolly adelgid life history in Utah. Jerald E. Dewey, USDA Forest Service, Bugwood.org The eggs hatch to give the first instar larva, known as a … USU Extension, the University of Utah, and other local, state and federal partners are working collaboratively to determine the best treatment options for our forest. A white woolly substance is produced by adults as they feed, usually on the trunk below where branches emerge. Infestations appear to be permanent (so long as host trees remain), because it takes only one surviving individual to maintain or start a colony. Found throughout both states, most commonly in the Cascade and coastal mountain ranges, western valleys and lowlands, and in the Blue Mountains of eastern Oregon and Washington. Research Paper, PNW-35. Balsam woolly adelgid females are softbodied, spherical, purplish-black, wingless insects. Mitchell, R.G., and P.E. In about 1900, a tiny insect called balsam woolly adelgid (Adelges piceae), a European native, appeared in North America on balsam firs (Abies balsamea) in New England and Canada. Although the rapid killing of native trees has become less evident since the mid-1900’s, this non-native insect nevertheless continues to cause significant negative impacts to native ecosystems. Balsam woolly adelgids (Adelges piceae) are small wingless insects that infest and kill firs, especially balsam fir and Fraser fir. BWA feast on true fir trees, including subalpine firs trees and white firs trees. The infestation in Utah has spread south from Idaho into Northern Utah forests, and has been confirmed in Lambs Canyon, Millcreek Canyon, Big Cottonwood Canyon, Little Cottonwood Canyon, and American Fork Canyon. West. The eggs are laid under the visible white, woolly tufts on the bark of the tree bole or on branches. As it initially spread throughout the Pacific Northwest, balsam woolly adelgid caused extensive mortality of subalpine, grand, and Pacific silver firs during the late 1950’s and 1960’s. The adults lay a cluster of orange eggs on the bark beside them (see second picture below). Under the wool Adelges piceaeadults are less than 1mm long, blackish-purple and roughly spherical in shape (see first picture below). Chronic crown infestations kill trees more slowly, causing tree crowns to become narrow and misshapen, with thin foliage, shortened lateral branches, stunted terminal growth, and tops that may droop at an angle to the main stem or be broken near the apex. R6-NR-FID-PR-01-06. Increased deadfall increases fuel loads and may heighten the potential for severe wildfires. Subalpine fir is the most susceptible species, followed by Pacific silver fir and grand fir. Population dynamics, climatic factors, and other variables are still being studied. The balsam woolly adelgid (Adelges piceae) (BWA) is a tiny, soft-bodied insect which appears when adult as a white, woolly spot on true firs. After this discovery, the species was found to be gradually dispersing to the other Atlantic provinces. In Europe, where it is indigenous, the adelgid causes little damage to its principle host plant, Abies alba. For Sci. There are nearly 1.9 billion balsam fir trees in Michigan’s forests. Trees of these species are frequently killed by heavy or prolonged infestations. Balsam Woolly Adelgid (wool removed) The balsam woolly adelgid is an insect that infests Balsam and Fraser fur trees, killing a once healthy tree in only 3 to 4 years. Given enough time, persistent branch gouting infestations that halt new growth in the crowns are capable of causing tree mortality. https://www.fs.fed.us/rm/ogden/pdfs/wasatch.pdf, https://www.usgs.gov/mission-areas/water-resources/science/water-quality-after-wildfire?qt-science_center_objects=0#qt-science_center_objects. They are about 1⁄25 inch long (< 1 mm) and are not mobile. The cycle of egg laying, hatching, crawler dispersal, resting, and development into adults repeats for each generation. The cottony tufts conceal amber-colored eggs and stationary feeding adults, which are dark purple, nearly round, and about 1mm in length. When BWA was detected in the forests of the Pacific Northwest in the late 1950’s, the agent wasn’t a primary concern for forestry management professionals. On relatively dry sites at high elevations near timberline, infestations in subalpine fir appear to be rare and, when they do occur, somewhat ephemeral in nature. By influencing stand microclimate and tree vigor, defoliators may also interact with balsam woolly adelgid in ways that are not yet fully understood. The balsam woolly adelgid, a species introduced from Europe, was first reported in Canada in 1910, in southern Nova Scotia. A flat top or weak terminal that is slanted, swollen twigs that drop their needles (referred to as gouting), dead shoots or branches and wilted appearance of shoots are common symptoms. Subalpine fir is susceptible at all locations except near timberline, and severe adelgid infestations are especially common on the edges of alpine meadows and lakes, avalanche chutes, and lava beds. BWA is an introduced pest of true firs that has spread throughout the southern half of the State. BWA infestations primarily target true fir trees, with subalpine fir being the most susceptible species. The balsam woolly adelgid, an insect species native to Europe that was inadvertently introduced to eastern North America about 1900, was first noted in the Pacific Northwest in 1930 damaging grand fir trees in the Willamette Valley. Stem infestations that are not confined to the lower bole cause the greatest amount of tree mortality. This can result in heightened. Share. The jury is still out in terms of the best practices to manage this insect and its spread. Shasta red fir, noble fir, and white fir growing in natural stands are resistant to infestation, but have been readily infested and killed when planted at low elevations in ornamental plantings or arboreta. The most frequently attacked true fir species are Abies balsamea, Abies fraseri, Abies lasiocarpa, Abies amabilis and Abies grandis (Foottit and Mackauer, 1980, 1983). Balsam woolly adelgid feeding frequently causes “gouting”, i.e. DESCRIPTION OF DAMAGE Introduced from Europe around 1900, the balsam woolly adelgid is considered a serious pest of forest, seed production, landscape, and Christmas trees. Each female produces 50 to 200 eggs. Unfortunately, they are under attack from a non-native insect called the hemlock woolly adelgid (Adelges tsugae). All individuals in the United States are females capable of reproducing without males. Balsam Woolly Adelgid Overview 1 Life History 2 Natural Control 2 Silvicultural Alternatives 3 Chemical Control 3 Recognizing adelgid damage 4 Other Reading 4 Field Guide Management Guide Index Topics Balsam woolly adelgid was discovered in northern Idaho in 1983 feeding predominantly on subalpine fir and to a less extent, grand fir. Newly hatched crawlers disperse within a tree through active locomotion or are carried longer distances by wind currents and perhaps incidentally by birds or mammals. It generally concentrates either on the outer portions of tree crowns or on the main stem and large branches. Hosts: Ok, enough of Dr. Doom. Balsam woolly adelgid inhibits the ability of some host species to persist in certain native environments by decreasing seed production and causing slow decline and mortality of older trees. Adelgid infestations weaken trees, cause foliage to become sparse, and can kill trees. Forest Insect & Disease Leaflet 118 (revised). Host species have unique responses and susceptibilities that tend to vary with location (Table 1). The balsam woolly adelgid injects saliva into its host plant when feeding. BWA has primarily been known to infest subalpine fir trees at elevations below 7,500 ft, but it hasn’t been documented in Utah’s valleys. Long-legged, very active, amber-colored crawlers also may be present. In 1928 it was found for the first time in a western state, on ornamental firs near San Francisco. The balsam woolly adelgid is an imported pest of the balsam fir forest. ).In its native range, HWA is not a serious pest because populations are managed by natural predators and parasitoids and by host resistance. Various chemical, biological, and mechanical removal techniques are also being vetted. After this discovery, the species was found to be gradually dispersing to the other Atlantic provinces. http://www.fs.usda.gov/Internet/FSE_DOCUMENTS/fsbdev2_043667.pdf. Current infestations more commonly are characterized by less dramatic chronic crown infestations. In addition, susceptible trees make up a much smaller percentage of their forests. ‘Wool-covered’ balsam woolly adelgid adults feeding near the base of an infested tree (Photo: Danielle Malesky, Forest Health Protection) Why are BWA concerning to the Central Wasatch? Balsam woolly adelgids (Adelges piceae) are small wingless insects that infest and kill firs, especially balsam fir and Fraser fir.They are an invasive species from Europe introduced to the United States around 1900.. Because this species is not native to the United States, the Fraser fir has not evolved any type of defense against it. Species similar to or like Balsam woolly adelgid. swollen, deformed branches and persistent woody swellings at branch nodes and terminal buds, and bark calluses. BALSAM WOOLLY ADELGID ALERT The balsam woolly adelgid (BWA), Adelges piceae (Ratz.) Forest health experts then “ground-truth” the probable areas and remove bark samples from infested trees. These factors played into the lack of research and development of appropriate management strategies. Later, it appeared on the west coast • California, 1928 on ornamental firs near San Francisco • Oregon, 1930 on grand fir near Salem This was because BWA does not attack the most desirable trees, those that are used for forest products. The hemlock woolly adelgid (/ ə ˈ d ɛ l. dʒ ɪ d /; Adelges tsugae), or HWA, is an insect of the order Hemiptera (true bugs) native to East Asia.It feeds by sucking sap from hemlock and spruce trees (Tsuga spp. Infestations may be categorized by whether they occur primarily on the main stem of the tree (stem infestations), or occur primarily in the branches and twigs of the crown (crown infestations). 16(3)121-126. For. Balsam woolly adelgid infestations sometimes alter successional pathways, causing sites to be dominated by non-host or less susceptible tree species. Is there enough concern for that land management agencies might regulate the movement of firewood or cutting of Christmas trees? It is a wingless, soft-bodied sucking insect with a life cycle consisting of several stages, including egg, “crawler”, and stationary immature and adult stages. On-Line Information – NC State University Balsam woolly adelgid. Balsam woolly adelgids (BWA) were first noticed in this country in Brunswick, Maine, in 1908. Like the dreaded hemlock woolly adelgid, this tiny, wingless, introduced insect feeds by inserting its sucking mouthparts into a tree. A stand severity rating developed by Hrinkevich et al. It is currently found in the northeastern U.S., the Canadian Maritimes, British Columbia and the Pacific Northwest. Balsam woolly adelgid. The balsam woolly adelgid is a small, aphid-like insect that threatens the . Adult female of Adelges piceae (balsam woolly adelgid) showing its ventral face and the long stylet that is normally inserted within the tree tissues. This microscopic invasive insect is native to south central Europe and entered the United States by hitching a ride on nursery stock imported to both the east and west coast. The balsam woolly adelgid is considered a serious pest of forests, seed production, landscapes, and Christmas trees. 1966. 2006. Photo credit: Diane Alston. They inject a salivary substance into the tree during feeding, causing the formation of abnormal wood structure that interferes with the normal transport of water and nutrients within a tree. Field Guide to Common Diseases and Insect Pests of Oregon and Washington Conifers. Balsam woolly adelgids feed by inserting long, straw-like mouthparts through the bark of tree boles, branches, and twigs and extracting tree sap. Why we care: Balsam woolly adelgid (BWA) is a sap-feeding insect that attacks true fir trees, including balsam fir and Fraser fir. Bole infestations can migrate along the stem over time as old feeding sites become exhausted of available nutrients and crawlers move on to establish new infestations elsewhere. 1 Indicates the appropriate time for monitoring … During the winter, immature nymphs can be found on bark. 337 pp. Wildfires may also adversely affect our watershed by, altering the rapidity of runoff. Experts are able to identify new BWA infestations through aerial detection surveys, in which the mortality of subalpine fir trees becomes apparent to the trained eye. 2006. Mitchell. Hrinkevich, K.H., R.A. Progar, and D.C. Shaw. Required fields are marked *, 41 N Rio Grande Street, Suite 102  Population dynamics, climatic factors, and other variables are still being studied. Portland, OR: USDA Forest Service, Pacific Northwest Region. Possible changes in turbidity and chemical composition can also be costly for water treatment plants and could delay water delivery to faucets in Salt Lake City. They are dark and have white, waxy rods down their backs and around the edges of their bodies. Wool often remains on the bark throughout the year. Balsam woolly adelgid appears to be most successful on hosts growing at low elevations for their species ranges, and on wet sites. As the mature, they continue to secrete this waxy substance, which gives them a covering that may cause them to resemble minute cotton balls by … At this stage, they closely resemble the eggs of balsam twig aphid. Figure X. Balsam woolly adelgid life history in Utah. has been very abundant in the last several years in Maine and feeding activity by this pest has resulted in serious injury to or death of large volumes of balsam fir. It is also eliminating subalpine fir as a pioneer species in important mountain environments such as alpine meadows, avalanche chutes, and lava beds. The balsam woolly adelgid (Adelges piceae), a native of Europe, was first located in the southern Appalachians in 1957 on Mount Mitchell, North Carolina (Figure 1).It has become a major pest of Fraser fir (Abies fraserii) in the southern Appalachians.Fraser fir is an endemic southern Appalachian tree and the only fir native to the southeastern United States. Susceptibility is variable across the host ranges, and is strongly associated with elevation and geographic location (Table 1). Hrinkevich, K.H., R.A. Progar, and D.C. Shaw. The saliva is toxic to the plant and inhibits bud formation and causes long-term tree decline. Once a crawler selects a place to feed and inserts its mouthparts into the bark, that individual never moves from that location. In some locations, understory host tree growth and survival also are negatively affected. While most Utahans know of the bark beetle infestations occurring throughout the state, many are unaware of another lethal agent affecting our forests: balsam wooly adelgids, or BWA. In managed host stands growing in susceptible locations, managers can reduce impacts when regenerating, thinning, or partial cutting by planting and selecting for resistant and non-host species, and perhaps by selecting for retention mature individuals that appear resistant. The balsam woolly adelgid, an insect species native to Europe that was inadvertently introduced to eastern North America about 1900, was first noted in the Pacific Northwest in 1930 damaging grand fir trees in the Willamette Valley. Wayne Brewer, Auburn University, Bugwood.org Grand fir is especially heavily colonized in the Willamette Valley, Puget Sound trough, and along coastal streams. Species delimitation and invasion history of the balsam woolly adelgid, Adelges (Dreyfusia) piceae (Hemiptera: Aphidoidea: Adelgidae), species complex Balsam woolly adelgids have two to four generations per year. Where are they found and how do they spread? Ragenovich, I.R. Balsam Woolly Adelgid (Adelges piceae) Distribution: Introduced from Europe around 1900, this pest is now common throughout eastern North America wherever true firs are grown. Salt Lake City, UT 84101. If you have true firs and in particular, Sub-alpine fir in your landscape that are suffering from Balsam Wooly Adelgid damage, we can provide a once-a-year treatment solution that will stop the infestation, provided it hasn’t progressed to the trunk of the tree. ; Picea spp. Except near timberline, susceptible at all locations, and especially around swamps, lakes, streams, meadows, avalanche chutes, and lava beds. http://www.biodiversitylibrary.org/bibliography/80321. 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