Spruce Budworm
Encyclopedia
Spruce budworms and relatives are a group of closely related insects in the genus Choristoneura. Most are serious pests of conifers. There are nearly a dozen Choristoneura species, subspecies, or forms, with a complexity of variation among populations found throughout much of the United States
and Canada
, and about again this number in Eurasia
.
and Coast Mountains
. The first recorded outbreak was in 1909 on the southeastern part of Vancouver Island
in British Columbia
, Canada. Since that year, infestations have frequently been reported in western Canada.
The budworm was first recorded in 1914 in the United States, in Oregon
. However, it was not initially recognized as a serious threat to coniferous forests in the western U.S. Aerial spraying apparently terminated some smaller epidemics in the southern and central Rockies; others subsided naturally. The insect then appeared to be dormant in US forests until 1922, when two outbreaks were reported near Priest Lake
in northern Idaho
. Since then, significant outbreaks in the Rockies and in the Pacific Northwest
have caused top-killing and serious economic losses in tree growth. Tree mortality from budworm can occur in regeneration, sapling, and pole-sized trees. Trees in mature stands severely defoliated by the western spruce budworm may become susceptible to bark beetles, which kill mature trees.
Considered the most destructive defoliator in British Columbia, sustained outbreaks of the Western Spruce Budworm resulted in defoliation of over 100,000 hectares (247,105 acres) in the Fraser Canyon
- Lillooet
- Pemberton
area from 1949-58. From 1970 -2001 further outbreaks occurred over a much larger area including the area of the previous outbreaks, as well as the Thompson
and South Okanagan
areas in 1970-2001.
There is no typical pattern for Western Spruce Budworm epidemics. Most of the early epidemics subsided naturally after a few years. Others persisted longer, but without spreading over large areas. An epidemic which began in 1949 in the northern Rocky Mountains has persisted for over 30 years despite insecticidal treatment of more than 6,000,000 acres (24,300 km²) between 1952 and 1966.
Larvae develop through six stages. Newly hatched larvae are yellow-green with brown heads. In the next three stages, larvae have black heads and collars and orange- or cinnamon-brown bodies. In the fifth stage, larvae have reddish-brown heads marked with black triangles, black collars, and pale olive-brown bodies marked with small whitish spots. Mature larvae are 1 to 11/4 inches (25 to 32 mm) long, with tan or light chestnut-brown heads and collars and olive- or reddish-brown bodies with large ivory-colored areas.
Pupae are 1/2 to 5/8 inch (13 to 16 mm) long, broad at the head end, and narrower toward the tail. They are brownish-yellow or brownish-green at first, and later turn reddish-brown.
The adults mate, and within 7 to 10 days, the female deposits her eggs and then dies. Each female deposits approximately 150 eggs, usually on the underside of conifer needles. Eggs are laid in one to three-row masses containing a few to 130 eggs, with an average of 25 to 40 eggs per mass.
Larvae hatch from eggs in about 10 days. Larvae do not feed, but seek sheltered places under bark scales or in and among lichens on the tree bole or limbs. Here, they spin silken tents in which they remain inactive through the winter.
In early May to late June, larvae leave their hibernacula to search for food. They first mine or tunnel into year-old needles, closed buds, or newly developing vegetative or reproductive buds.
New foliage, which is normally the preferred food, is usually entirely consumed or destroyed before larvae will feed on older needles. Larvae become full grown usually in early July about 30 to 40 days after leaving their overwintering sites.
Larvae pupate in webs of silk they have spun either at the last feeding site or elsewhere on the tree. The pupal stage usually lasts about 10 days.
of budworm outbreaks holds that particularly major infestations occur every 40–60 years, as the result of a cusp-catastrophe event, whereby populations jump suddenly from endemic to epidemic levels. An alternative theory holds that outbreaks are the result of spatially synchronized population oscillations that are caused by delayed density-dependent feedback (from various mortality agents) which are synchronized via a process of entrainment
.
The first recorded outbreak of the spruce budworm in the United States occurred in Maine about 1807. Another outbreak followed in 1878. Since 1909 there have been waves of budworm outbreaks throughout the Eastern United States and Canada. The States most often affected are Maine
, New Hampshire
, New York
, Michigan
, Minnesota
, and Wisconsin
. These outbreaks have resulted in the loss of millions of cords of spruce and fir. In 20th century eastern Canada, the major outbreaks occurred in the time periods ~1910-20, ~1940-50, and ~1970-80. Longer-term tree-ring studies suggest that spruce budworm outbreaks have been recurring every three decades or so since the 16th century. Paleoecological studies suggest the spruce budworm has been outbreaking in eastern North America for thousands of years.
Balsam Fir
is the species most severely damaged by the budworm in the Eastern United States. White, Red, and Black Spruce
are suitable host trees and some feeding may occur on tamarack, pine, and hemlock. Spruce
mixed with Balsam Fir is more likely to suffer budworm damage than spruce in pure stands.
The range of the spruce bud-worm includes the Northern States east of Montana but the budworm is found wherever host species grow.
, vertebrate and invertebrate predators, and adverse weather conditions. During prolonged outbreaks when stands become heavily defoliated, starvation can be an important mortality factor in regulating populations.
This species is a favoured food of the Cape May Warbler
, which is therefore closely associated with its host plant, Balsam Fir
. This bird
, and the Tennessee
and Bay-breasted Warbler
s, which also have a preference for budworm, lay more eggs and are more numerous in years of budworm abundance.
Natural enemies are probably responsible for considerable mortality when budworm
populations are low, but seldom have a regulating influence when populations are
in epidemic proportions.
Chemical insecticides such as malathion, carbaryl, and acephate can substantially reduce budworm. Microbial insecticides such as the bacterium Bacillus thuringiensis
, a naturally occurring, host-specific pathogen that affects only the larvae of lepidopterous insects is environmentally safe to use in sensitive areas such as campgrounds or along rivers or streams where it may not be desirable to use chemical insecticides.
/Spencer Tracy
film Desk Set
, the market cost of the annual depredations of the Spruce Budworm on United States
forests is invoked as an example reference question in comparing the response times of human reference
librarian
s and early computer database
s.
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
and Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
, and about again this number in Eurasia
Eurasia
Eurasia is a continent or supercontinent comprising the traditional continents of Europe and Asia ; covering about 52,990,000 km2 or about 10.6% of the Earth's surface located primarily in the eastern and northern hemispheres...
.
Species
- Choristoneura adumbratanus (Walsingham, 1900)
- Choristoneura africana Razowski, 2002
- Choristoneura albaniana (Walker, 1863)
- Choristoneura argentifasciata Heppner, 1989
- Choristoneura biennis Freeman, 1967
- Choristoneura bracatana (Rebel, in Rebel & Rogenhofer, 1894)
- Choristoneura carnana (Barnes & Busck, 1920)
- Choristoneura colyma Razowski, 2006
- Choristoneura conflictanaChoristoneura conflictanaThe Large Aspen Tortrix is a moth of the Tortricidae family. It is found from the Pacific to the Atlantic coast and from Alaska to California, Arizona, and New Mexico....
(Walker, 1863) - Choristoneura diversana (Hubner, [1814-1817])
- Choristoneura evanidana (Kennel, 1901)
- Choristoneura ferrugininotata Obraztsov, 1968
- Choristoneura fractivittanaChoristoneura fractivittanaThe Broken-banded Leafroller or Dark-banded Fireworm is a moth of the Tortricidae family.-Distribution:It is found from Quebec and Maine to Florida, west to Texas, north to western Canada.-Description:...
(Clemens, 1865) - Choristoneura fumiferana (Clemens, 1865), Eastern Spruce Budworm
- Choristoneura griseicoma (Meyrick, 1924)
- Choristoneura hebenstreitellaChoristoneura hebenstreitellaThe Mountain-ash tortricid is a moth of the family Tortricidae. It is found in Western Europe, Central Europe and the Near East.The wingspan is 19–30 mm. The moth flies from May to July. ....
(Muller, 1764), Mountain-ash tortricidChoristoneura hebenstreitellaThe Mountain-ash tortricid is a moth of the family Tortricidae. It is found in Western Europe, Central Europe and the Near East.The wingspan is 19–30 mm. The moth flies from May to July. .... - Choristoneura improvisana (Kuznetsov, 1973)
- Choristoneura jecorana (Kennel, 1899)
- Choristoneura jezoensis Yasuda & Suzuki, 1987
- Choristoneura lafauryana (Ragonot, 1875)
- Choristoneura lambertianaChoristoneura lambertianaThe Sugar Pine Tortrix is a moth of the Tortricidae family. It is found in the Eastern parts of North America and the North of the United States .The wingspan is 18–23 mm....
(Busck, 1915) - Choristoneura longicellanus (Walsingham, 1900)
- Choristoneura luticostana (Christoph, 1888)
- Choristoneura metasequoiacola Liu, 1983
- Choristoneura murinanaChoristoneura murinanaChoristoneura murinana is a moth of the Tortricidae family. It is found in Middle and Central Europe and the Near East and in North America.The wingspan is 17–24 mm....
(Hubner, [1796-1799]) - Choristoneura neurophaea (Meyrick, 1932)
- Choristoneura obsoletana (Walker, 1863)
- Choristoneura occidentalis Freeman, 1967, Western Spruce Budworm
- Choristoneura oraeChoristoneura oraeThe Spruce Budworm is a moth of the Tortricidae family. It is found in North America.The wingspan is about 24 mm.The larvae feed on Picea species....
Freeman, 1967 - Choristoneura parallela (Robinson, 1869)
- Choristoneura pinusChoristoneura pinusThe Jack Pine Budworm is a moth of the Tortricidae family. It is found in Jack pine forests in Canada from Atlantic provinces to Cypress Hills on the Alberta-Saskatchewan border as well as northern United States from New England to the lake states.The wingspan is 18–24 mm for males and...
Freeman, 1953, Jack Pine Budworm - Choristoneura propensa Razowski, 1992
- Choristoneura quadratica Diakonoff, 1955
- Choristoneura retiniana (Walsingham, 1879)
- Choristoneura rosaceanaChoristoneura rosaceanaThe Oblique Banded Leaf Roller or Rosaceous Leaf Roller is a moth of the Tortricidae family. It is native to North America, but has been accidentally introduced into other parts of the world....
(Harris, 1841) - Choristoneura simonyi (Rebel, 1892)
- Choristoneura spaldingana Obraztsov, 1962
- Choristoneura thyrsifera Razowski, 1984
- Choristoneura zapulata (Robinson, 1869)
Western Spruce Budworm
Western Spruce Budworm is the most destructive defoliator of coniferous forests in Western North America. It is now widely distributed throughout the RockyRocky Mountains
The Rocky Mountains are a major mountain range in western North America. The Rocky Mountains stretch more than from the northernmost part of British Columbia, in western Canada, to New Mexico, in the southwestern United States...
and Coast Mountains
Coast Mountains
The Coast Mountains are a major mountain range, in the Pacific Coast Ranges, of western North America, extending from southwestern Yukon through the Alaska Panhandle and virtually all of the Coast of British Columbia. They are so-named because of their proximity to the sea coast, and are often...
. The first recorded outbreak was in 1909 on the southeastern part of Vancouver Island
Vancouver Island
Vancouver Island is a large island in British Columbia, Canada. It is one of several North American locations named after George Vancouver, the British Royal Navy officer who explored the Pacific Northwest coast of North America between 1791 and 1794...
in British Columbia
British Columbia
British Columbia is the westernmost of Canada's provinces and is known for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . Its name was chosen by Queen Victoria in 1858...
, Canada. Since that year, infestations have frequently been reported in western Canada.
The budworm was first recorded in 1914 in the United States, in Oregon
Oregon
Oregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...
. However, it was not initially recognized as a serious threat to coniferous forests in the western U.S. Aerial spraying apparently terminated some smaller epidemics in the southern and central Rockies; others subsided naturally. The insect then appeared to be dormant in US forests until 1922, when two outbreaks were reported near Priest Lake
Priest Lake
Priest Lake, Idaho, United States is located in the northernmost portion of the Idaho Panhandle, 80 miles north of Spokane Washington, with the northern end of the lake extending to within 15 miles of the Canadian border. The primary lake, lower Priest is 19 miles long and over 300 feet deep...
in northern Idaho
Idaho
Idaho is a state in the Rocky Mountain area of the United States. The state's largest city and capital is Boise. Residents are called "Idahoans". Idaho was admitted to the Union on July 3, 1890, as the 43rd state....
. Since then, significant outbreaks in the Rockies and in the Pacific Northwest
Pacific Northwest
The Pacific Northwest is a region in northwestern North America, bounded by the Pacific Ocean to the west and, loosely, by the Rocky Mountains on the east. Definitions of the region vary and there is no commonly agreed upon boundary, even among Pacific Northwesterners. A common concept of the...
have caused top-killing and serious economic losses in tree growth. Tree mortality from budworm can occur in regeneration, sapling, and pole-sized trees. Trees in mature stands severely defoliated by the western spruce budworm may become susceptible to bark beetles, which kill mature trees.
Considered the most destructive defoliator in British Columbia, sustained outbreaks of the Western Spruce Budworm resulted in defoliation of over 100,000 hectares (247,105 acres) in the Fraser Canyon
Fraser Canyon
The Fraser Canyon is an 84 km landform of the Fraser River where it descends rapidly through narrow rock gorges in the Coast Mountains en route from the Interior Plateau of British Columbia to the Fraser Valley...
- Lillooet
Lillooet, British Columbia
Lillooet is a community on the Fraser River in western Canada, about up the British Columbia Railway line from Vancouver. Situated at an intersection of deep gorges in the lee of the Coast Mountains, it has a dry climate- of precipitation is recorded annually at the town's weather station,...
- Pemberton
Pemberton, British Columbia
Pemberton is a village north of Whistler in the Pemberton Valley of British Columbia in Canada, with a population of 2,192. Until the 1960s the village could be accessed only by train but that changed when Highway 99 was built through Whistler and Pemberton.-Climate:The climate of Pemberton is...
area from 1949-58. From 1970 -2001 further outbreaks occurred over a much larger area including the area of the previous outbreaks, as well as the Thompson
Thompson Plateau
The Thompson Plateau, also known as the Okanagan-Thompson Plateau, forms the southern portion of the Interior Plateau of British Columbia, Canada, lying to the west of Okanagan Lake, south of the Thompson River and to the east of the Fraser River...
and South Okanagan
South Okanagan
South Okanagan was a provincial electoral district in the Canadian province of British Columbia beginning with the election of 1916. Following the 1975 election boundary revisions accompanied the riding's renaming to Okanagan South...
areas in 1970-2001.
There is no typical pattern for Western Spruce Budworm epidemics. Most of the early epidemics subsided naturally after a few years. Others persisted longer, but without spreading over large areas. An epidemic which began in 1949 in the northern Rocky Mountains has persisted for over 30 years despite insecticidal treatment of more than 6,000,000 acres (24,300 km²) between 1952 and 1966.
Description
Adult moths are about 1/2 inch (12.7 mm) long and have a wing-spread of 7/8 to 11/8 inches (22 to 28mm). Moths of both sexes are similar in appearance, although the females are a bit more robust than males. Both sexes fly. The gray- or orange-brown forewings are banded or streaked, and each usually has a conspicuous white dot on the wing margin. Eggs are oval, light green, and about 3/64 inch (1.2mm) long and overlap like shingles.Larvae develop through six stages. Newly hatched larvae are yellow-green with brown heads. In the next three stages, larvae have black heads and collars and orange- or cinnamon-brown bodies. In the fifth stage, larvae have reddish-brown heads marked with black triangles, black collars, and pale olive-brown bodies marked with small whitish spots. Mature larvae are 1 to 11/4 inches (25 to 32 mm) long, with tan or light chestnut-brown heads and collars and olive- or reddish-brown bodies with large ivory-colored areas.
Pupae are 1/2 to 5/8 inch (13 to 16 mm) long, broad at the head end, and narrower toward the tail. They are brownish-yellow or brownish-green at first, and later turn reddish-brown.
Life History
Throughout most of its range, the Western Spruce Budworm completes one cycle of development from egg to adult within 12 months. Moths emerge from pupal cases usually in late July or early August; in the southern Rockies, adults often begin emerging in early July.The adults mate, and within 7 to 10 days, the female deposits her eggs and then dies. Each female deposits approximately 150 eggs, usually on the underside of conifer needles. Eggs are laid in one to three-row masses containing a few to 130 eggs, with an average of 25 to 40 eggs per mass.
Larvae hatch from eggs in about 10 days. Larvae do not feed, but seek sheltered places under bark scales or in and among lichens on the tree bole or limbs. Here, they spin silken tents in which they remain inactive through the winter.
In early May to late June, larvae leave their hibernacula to search for food. They first mine or tunnel into year-old needles, closed buds, or newly developing vegetative or reproductive buds.
New foliage, which is normally the preferred food, is usually entirely consumed or destroyed before larvae will feed on older needles. Larvae become full grown usually in early July about 30 to 40 days after leaving their overwintering sites.
Larvae pupate in webs of silk they have spun either at the last feeding site or elsewhere on the tree. The pupal stage usually lasts about 10 days.
Eastern Spruce Budworm
The eastern version of the Spruce Budworm is Choristoneura fumiferana, which is one of the most destructive native insects in the northern spruce and fir forests of the Eastern United States and Canada. According to one common theory, popularized in the 1970s, periodic outbreaks of the spruce budworm are a part of the natural cycle of events associated with the maturing of balsam fir. The catastrophe theoryCatastrophe theory
In mathematics, catastrophe theory is a branch of bifurcation theory in the study of dynamical systems; it is also a particular special case of more general singularity theory in geometry....
of budworm outbreaks holds that particularly major infestations occur every 40–60 years, as the result of a cusp-catastrophe event, whereby populations jump suddenly from endemic to epidemic levels. An alternative theory holds that outbreaks are the result of spatially synchronized population oscillations that are caused by delayed density-dependent feedback (from various mortality agents) which are synchronized via a process of entrainment
Entrainment (chronobiology)
Entrainment, within the study of chronobiology, occurs when rhythmic physiological or behavioral events match their period and phase to that of an environmental oscillation. A common example is the entrainment of circadian rhythms to the daily light–dark cycle, which ultimately is determined by...
.
The first recorded outbreak of the spruce budworm in the United States occurred in Maine about 1807. Another outbreak followed in 1878. Since 1909 there have been waves of budworm outbreaks throughout the Eastern United States and Canada. The States most often affected are Maine
Maine
Maine is a state in the New England region of the northeastern United States, bordered by the Atlantic Ocean to the east and south, New Hampshire to the west, and the Canadian provinces of Quebec to the northwest and New Brunswick to the northeast. Maine is both the northernmost and easternmost...
, New Hampshire
New Hampshire
New Hampshire is a state in the New England region of the northeastern United States of America. The state was named after the southern English county of Hampshire. It is bordered by Massachusetts to the south, Vermont to the west, Maine and the Atlantic Ocean to the east, and the Canadian...
, New York
New York
New York is a state in the Northeastern region of the United States. It is the nation's third most populous state. New York is bordered by New Jersey and Pennsylvania to the south, and by Connecticut, Massachusetts and Vermont to the east...
, Michigan
Michigan
Michigan is a U.S. state located in the Great Lakes Region of the United States of America. The name Michigan is the French form of the Ojibwa word mishigamaa, meaning "large water" or "large lake"....
, Minnesota
Minnesota
Minnesota is a U.S. state located in the Midwestern United States. The twelfth largest state of the U.S., it is the twenty-first most populous, with 5.3 million residents. Minnesota was carved out of the eastern half of the Minnesota Territory and admitted to the Union as the thirty-second state...
, and Wisconsin
Wisconsin
Wisconsin is a U.S. state located in the north-central United States and is part of the Midwest. It is bordered by Minnesota to the west, Iowa to the southwest, Illinois to the south, Lake Michigan to the east, Michigan to the northeast, and Lake Superior to the north. Wisconsin's capital is...
. These outbreaks have resulted in the loss of millions of cords of spruce and fir. In 20th century eastern Canada, the major outbreaks occurred in the time periods ~1910-20, ~1940-50, and ~1970-80. Longer-term tree-ring studies suggest that spruce budworm outbreaks have been recurring every three decades or so since the 16th century. Paleoecological studies suggest the spruce budworm has been outbreaking in eastern North America for thousands of years.
Balsam Fir
Balsam Fir
The balsam fir is a North American fir, native to most of eastern and central Canada and the northeastern United States .-Growth:It is a small to medium-size evergreen tree typically tall, rarely to tall, with a narrow conic crown...
is the species most severely damaged by the budworm in the Eastern United States. White, Red, and Black Spruce
Black Spruce
Picea mariana is a species of spruce native to northern North America, from Newfoundland west to Alaska, and south to northern New York, Minnesota and central British Columbia...
are suitable host trees and some feeding may occur on tamarack, pine, and hemlock. Spruce
Spruce
A spruce is a tree of the genus Picea , a genus of about 35 species of coniferous evergreen trees in the Family Pinaceae, found in the northern temperate and boreal regions of the earth. Spruces are large trees, from tall when mature, and can be distinguished by their whorled branches and conical...
mixed with Balsam Fir is more likely to suffer budworm damage than spruce in pure stands.
The range of the spruce bud-worm includes the Northern States east of Montana but the budworm is found wherever host species grow.
Controls
Budworm populations are usually regulated naturally by combinations of several natural factors such as insect parasitesParasitism
Parasitism is a type of symbiotic relationship between organisms of different species where one organism, the parasite, benefits at the expense of the other, the host. Traditionally parasite referred to organisms with lifestages that needed more than one host . These are now called macroparasites...
, vertebrate and invertebrate predators, and adverse weather conditions. During prolonged outbreaks when stands become heavily defoliated, starvation can be an important mortality factor in regulating populations.
This species is a favoured food of the Cape May Warbler
Cape May Warbler
The Cape May Warbler, Dendroica tigrina, is a small New World warbler. It breeds in northern North America. Its breeding habitat spans across all but the westernmost parts of southern Canada, and into the Great Lakes region and New England. It is migratory, wintering in the West Indies...
, which is therefore closely associated with its host plant, Balsam Fir
Balsam Fir
The balsam fir is a North American fir, native to most of eastern and central Canada and the northeastern United States .-Growth:It is a small to medium-size evergreen tree typically tall, rarely to tall, with a narrow conic crown...
. This bird
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
, and the Tennessee
Tennessee Warbler
The Tennessee Warbler, Oreothlypis peregrina, is a New World warbler. It breeds in northern North America across Canada and the northern USA. It is migratory, wintering in southern Central America and northern Colombia and Venezuela, with a few stragglers going as far south as Ecuador. It is a...
and Bay-breasted Warbler
Bay-breasted Warbler
The Bay-breasted Warbler, Dendroica castanea , is a New World warbler. They breed in northern North America, specifically in Canada, into the Great Lakes region, and into northern New England....
s, which also have a preference for budworm, lay more eggs and are more numerous in years of budworm abundance.
Natural enemies are probably responsible for considerable mortality when budworm
populations are low, but seldom have a regulating influence when populations are
in epidemic proportions.
Chemical insecticides such as malathion, carbaryl, and acephate can substantially reduce budworm. Microbial insecticides such as the bacterium Bacillus thuringiensis
Bacillus thuringiensis
Bacillus thuringiensis is a Gram-positive, soil-dwelling bacterium, commonly used as a biological pesticide; alternatively, the Cry toxin may be extracted and used as a pesticide. B...
, a naturally occurring, host-specific pathogen that affects only the larvae of lepidopterous insects is environmentally safe to use in sensitive areas such as campgrounds or along rivers or streams where it may not be desirable to use chemical insecticides.
Appearances in the Media
In the Katharine HepburnKatharine Hepburn
Katharine Houghton Hepburn was an American actress of film, stage, and television. In a career that spanned 62 years as a leading lady, she was best known for playing strong-willed, sophisticated women in both dramas and comedies...
/Spencer Tracy
Spencer Tracy
Spencer Bonaventure Tracy was an American theatrical and film actor, who appeared in 75 films from 1930 to 1967. Tracy was one of the major stars of Hollywood's Golden Age, ranking among the top ten box office draws for almost every year from 1938 to 1951...
film Desk Set
Desk Set
Desk Set is a 1957 American romantic comedy film directed by Walter Lang and starring Spencer Tracy and Katharine Hepburn...
, the market cost of the annual depredations of the Spruce Budworm on United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
forests is invoked as an example reference question in comparing the response times of human reference
Library reference desk
The reference desk or information desk of a library is a public service counter where professional librarians provide library users with direction to library materials, advice on library collections and services, and expertise on multiple kinds of information from multiple sources.- Explanation...
librarian
Librarian
A librarian is an information professional trained in library and information science, which is the organization and management of information services or materials for those with information needs...
s and early computer database
Database
A database is an organized collection of data for one or more purposes, usually in digital form. The data are typically organized to model relevant aspects of reality , in a way that supports processes requiring this information...
s.