Choristoneura freemani

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Choristoneura freemani
Choristoneura freemani Razowski, 2008.jpg
Adult
Scientific classification Red Pencil Icon.png
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Lepidoptera
Family: Tortricidae
Genus: Choristoneura
Species:
C. freemani
Binomial name
Choristoneura freemani
Razowski, 2008 [1]
Synonyms
  • Choristoneura occidentalisFreeman, 1967 (preocc. Walsingham, 1891)

Choristoneura freemani, the western spruce budworm, is a species of moth of the family Tortricidae. It is the most destructive defoliator of coniferous forests in western North America.

Contents

Distribution

It is now widely distributed throughout the Rocky 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. [2]

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. [2]

Pinus contorta ssp. latifolia defoliated by western spruce budworm (Choristoneura freemani) near Blewett Pass summit, Chelan County Washington Pinus contorta var. latifolia & western spruce budworm 1.jpg
Pinus contorta ssp. latifolia defoliated by western spruce budworm (Choristoneura freemani) near Blewett Pass summit, Chelan County Washington

Impact

Considered the most destructive defoliator in British Columbia, sustained outbreaks of the western spruce budworm resulted in defoliation of over 100,000 hectares (250,000 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. [3]

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 (24,000 km2) between 1952 and 1966. [2]

Description

Western spruce budworm caterpillar, sixth (final) instar Wsprucebudworm.jpg
Western spruce budworm caterpillar, sixth (final) instar

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 cycle

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.

Taxonomy

The species was originally named Choristoneura occidentalis by Freeman. However, this name was already in use for an African species described by Walsingham. The replacement name for this North American species is Choristoneura freemani. [4]

Related Research Articles

<i>Choristoneura</i> Genus of moths in the family Tortricidae

Choristoneura is a genus of moths in the family Tortricidae. Several species are serious pests of conifers, such as spruce and are known as spruce budworms.

Tortricidae Family of tortrix moths

The Tortricidae are a family of moths, commonly known as tortrix moths or leafroller moths, in the order Lepidoptera. This large family has over 10,350 species described, and is the sole member of the superfamily Tortricoidea, although the genus Heliocosma is sometimes placed within this superfamily. Many of these are economically important pests. Olethreutidae is a junior synonym. The typical resting posture is with the wings folded back, producing a rather rounded profile.

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Western pine elfin Species of butterfly

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The gall adelgid is an adelgid species that produces galls in spruce trees. They infect the new buds of native spruce trees in the[foothills of the Rocky Mountains in the spring. They also attack blue spruce to a lesser degree. The insects complete two generations within the year. They require two different trees for its life cycle, the second being the Rocky Mountain Douglas-fir. They may also attack Sitka, Engelmann, or white spruce. The many different species of adelgids produce different galls on different spruce species.

<i>Choristoneura fumiferana</i> Species of moth

Choristoneura fumiferana, the eastern spruce budworm, is a species of moth of the family Tortricidae native to the eastern United States and Canada. The caterpillars feed on the needles of spruce and fir trees. Eastern spruce budworm populations can experience significant oscillations, with large outbreaks sometimes resulting in wide scale tree mortality. The first recorded outbreaks of the spruce budworm in the United States occurred in about 1807, and since 1909 there have been waves of budworm outbreaks throughout the eastern United States and Canada. In Canada, the major outbreaks occurred in periods circa 1910–20, c. 1940–50, and c. 1970–80, each of which impacted millions of hectares of forest. Longer-term tree-ring studies suggest that spruce budworm outbreaks have been recurring approximately every three decades since the 16th century, and paleoecological studies suggest the spruce budworm has been breaking out in eastern North America for thousands of years.

<i>Choristoneura occidentalis</i> Species of moth

Choristoneura occidentalis is a species of moth of the family Tortricidae. It is found in the Democratic Republic of Congo, South Africa, Tanzania and Gambia.

<i>Malacosoma californicum</i> Species of insect

Malacosoma californicum, the western tent caterpillar, is a moth of the family Lasiocampidae. It is a tent caterpillar. The Western Tent Caterpillar is found in southern Canada, the western United States, and parts of northern Mexico. There are currently six recognized subspecies of M. californicum. Western tent caterpillars are gregarious and will spend a large portion of their time with other caterpillars in silken tents constructed during their larval stage.

<i>Zeiraphera canadensis</i> Species of moth

Zeiraphera canadensis, the spruce bud moth, is a moth of the family Tortricidae. It is a small brown moth mainly found in North America, specifically New Brunswick, Quebec, and the north-eastern United States. The adult moth flutters quickly, and stays low among trees during the day and higher above tree cover after sunset. The spruce bud moth relies primarily on the white spruce tree as a host plant. Both male and female spruce bud moths mate multiply, however males have the ability to secrete accessory gland proteins that prevent female re-mating. The moth is univoltine, meaning only one generation hatches per year, and its eggs overwinter from July to May. The species Z. ratzeburgiana is very similar to Z. canadensis and can only be distinguished by the presence of an anal comb in Z. canadensis.

<i>Acleris semipurpurana</i> Species of moth

Acleris semipurpurana is a species in the moth family Tortricidae, and one of several species of moth commonly known as oak leaftier or oak leaf tier. The larvae feed on the leaves of oak trees in the Eastern United States and southeastern Canada which can be a major cause of defoliation. The loss of leaves can kill or damage the affected trees, which are chiefly in the Lobatae or red oak section of Quercus, or oaks.

<i>Archips semiferanus</i> Species of moth

Archips semiferanus is a species of moth in the family Tortricidae, and one of several species of moth commonly known as oak leafroller or oak leaf roller. The larvae feed on the leaves of oak trees in the eastern United States and southeastern Canada and are a major defoliator of oak trees, which can lead to tree mortality. In Pennsylvania in the late 1960s and early 1970s, oak leafrollers defoliated over 1,045,000 acres (423,000 ha).

<i>Epinotia nanana</i> Species of moth

Epinotia nanana, the European spruce needleminer, is a moth of the family Tortricidae. It is found from northern and central Europe to Russia and Mongolia.

Gypsy moths in the United States Spread of an invasive species

The gypsy moth was introduced in 1868 into the United States by Étienne Léopold Trouvelot, a French scientist living in Medford, Massachusetts. Because native silk-spinning caterpillars were susceptible to disease, Trouvelot imported the species in order to breed a more resistant hybrid species. Some of the moths escaped, found suitable habitat, and began breeding. The gypsy moth is now a major pest of hardwood trees in the Eastern United States.

<i>Orgyia pseudotsugata</i> Species of moth

Orgyia pseudotsugata, the Douglas-fir tussock moth, is a moth of the subfamily Lymantriinae first described by James Halliday McDunnough in 1921. It is found in western North America. Its population periodically irrupts in cyclical outbreaks. The caterpillars feed on the needles of Douglas fir, true fir, and spruce in summer, and moths are on the wing from July or August to November.

<i>Dioryctria reniculelloides</i> Species of moth

Dioryctria reniculelloides, the spruce coneworm, is a moth of the family Pyralidae. The species was first described by Akira Mutuura and Eugene G. Munroe in 1973. It is found from Nova Scotia to Alaska, south in the east to New York, and south in the west to California and New Mexico. It was recorded from China in 2009. Occasionally abundant, often in conjunction with epidemics of the spruce budworm, the spruce coneworm occurs through most or all of the range of spruce in North America, feeding on new foliage and cones of spruce, and often balsam fir. When abundant, it can be a serious pest "particularly on white spruce".

<i>Epinotia radicana</i> Species of moth

Epinotia radicana, the red-striped needleworm moth, is a species of moth of the family Tortricidae. It is found in western Canada, including British Columbia and the Alberta.

Archips packardianus, the spring spruce needle moth or spruce needleworm, is a species of moth of the family Tortricidae. Spruce needle worms are commonly found in small numbers on spruce and trees of other coniferous genera throughout most of Canada and the northeastern US. Archips packardiana overwinters as a tiny larva in a mined needle. Needle mining is resumed in the spring, the larvae later moving to feed on new foliage, where they spin considerable webbing. Full-grown larvae have a pale green head, sometimes patterned with brown, and a pale body and pale thoracic legs, and are about 20 mm long. The larva pupates, usually in the webbed needles, and the adult emerges in summer to early fall. The closely related Archips strianus is much less common, but probably has a habitat similar to that of A. packardiana. The larvae have dark thoracic legs and small dark areas around the base of the thoracic hairs. The habitat consists of coniferous and mixed woods.

Choristoneura biennis, the two-year-cycle budworm moth, is a species of moth of the family Tortricidae. It is found in Canada, where it has been recorded from Alberta and British Columbia.

<i>Gilpinia hercyniae</i> Species of sawfly

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Spruce sawflies are various sawfly species found in North America that feed on spruce. There are multiple species of sawflies known as spruce sawflies, including species in the genera Gilpinia, Pikonema, Pristiphora, and Cephalcia. Each kind of sawfly attacks particular parts of the spruce as larvae during different times of the year.

References

  1. tortricidae.com
  2. 1 2 3 Fellin, D. and J. Dewey (March 1992). Western Spruce Budworm Forest Insect & Disease Leaflet 53, U.S. Forest Service. Retrieved on: September 14, 2008.
  3. Natural Resources Canada. Western spruce budworm Archived 2007-05-27 at the Wayback Machine . Conifer Defoliating Insects of British Columbia. Canadian Forestry Service. Retrieved on: September 14, 2008.
  4. Gilligan, Todd M.; Brown, John W. (2014). "A new name for the western spruce budworm (Lepidoptera: Tortricidae)?". The Canadian Entomologist. 146 (6): 583–589. doi:10.4039/tce.2014.17. ISSN   0008-347X.

PD-icon.svg This article incorporates  public domain material from the United States Forest Service document: David G. Fellin, Jerald E. Dewey. "Forest Insect & Disease Leaflet 53: Western Spruce Budworm".