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 (taiga) regions of the Earth. Picea is the sole genus in the subfamily Piceoideae. Spruces are large trees, from about 20 to 60 m tall when mature, and have whorled branches and conical form. They can be distinguished from other members of the pine family by their needles (leaves), which are four-sided and attached singly to small persistent peg-like structures on the branches, and by their cones, which hang downwards after they are pollinated. The needles are shed when 4–10 years old, leaving the branches rough with the retained pegs. In other similar genera, the branches are fairly smooth.
The Pinaceae, or pine family, are conifer trees or shrubs, including many of the well-known conifers of commercial importance such as cedars, firs, hemlocks, piñons, larches, pines and spruces. The family is included in the order Pinales, formerly known as Coniferales. Pinaceae are supported as monophyletic by their protein-type sieve cell plastids, pattern of proembryogeny, and lack of bioflavonoids. They are the largest extant conifer family in species diversity, with between 220 and 250 species in 11 genera, and the second-largest in geographical range, found in most of the Northern Hemisphere, with the majority of the species in temperate climates, but ranging from subarctic to tropical. The family often forms the dominant component of boreal, coastal, and montane forests. One species, Pinus merkusii, grows just south of the equator in Southeast Asia. Major centres of diversity are found in the mountains of southwest China, Mexico, central Japan, and California.
A bark beetle is the common name for the subfamily of beetles Scolytinae. Previously, this was considered a distinct family (Scolytidae), but is now understood to be a specialized clade of the "true weevil" family (Curculionidae). Although the term "bark beetle" refers to the fact that many species feed in the inner bark (phloem) layer of trees, the subfamily also has many species with other lifestyles, including some that bore into wood, feed in fruit and seeds, or tunnel into herbaceous plants. Well-known species are members of the type genus Scolytus, namely the European elm bark beetle S. multistriatus and the large elm bark beetle S. scolytus, which like the American elm bark beetle Hylurgopinus rufipes, transmit Dutch elm disease fungi (Ophiostoma). The mountain pine beetle Dendroctonus ponderosae, southern pine beetle Dendroctonus frontalis, and their near relatives are major pests of conifer forests in North America. A similarly aggressive species in Europe is the spruce ips Ips typographus. A tiny bark beetle, the coffee berry borer, Hypothenemus hampei is a major pest on coffee plantations around the world.
The mountain pine beetle is a species of bark beetle native to the forests of western North America from Mexico to central British Columbia. It has a hard black exoskeleton, and measures approximately 5 millimetres, about the size of a grain of rice.
Verbenone is a natural organic compound classified as a terpene that is found naturally in a variety of plants. The chemical has a pleasant characteristic odor. Besides being a natural constituent of plants, it and its analogs are insect pheromones. In particular, verbenone when formulated in a long-lasting matrix has an important role in the control of bark beetles such as the mountain pine beetle and the Southern pine bark beetle.
The ant beetle, also known as the European red-bellied clerid, is a medium size insect, rather soft-bodied, with strong mandibles that can tear between the hard sclerotized integument of bark beetles. Larvae and adults are common predators of bark beetles in Europe.
The term mycangium is used in biology for special structures on the body of an animal that are adapted for the transport of symbiotic fungi. This is seen in many xylophagous insects, which apparently derive much of their nutrition from the digestion of various fungi that are growing amidst the wood fibers. In some cases, as in ambrosia beetles, the fungi are the sole food, and the excavations in the wood are simply to make a suitable microenvironment for the fungus to grow. In other cases, wood tissue is the main food, and fungi weaken the defense response from the host plant.
Dendroctonus rufipennis, the spruce beetle, is a species of bark beetle native to British Columbia, Newfoundland and Labrador, Nova Scotia, Ontario, Quebec, Northern Manitoba, the Yukon, Alaska, Colorado, Wyoming, Montana, and Maine. They are known to destroy forests of spruce trees including Engelmann, White, Sitka, and Colorado blue spruce. Adults average 4 to 7 mm in length.
Dendroctonus frontalis, the southern pine beetle, often shortened to simply SPB, is a species of bark beetle native to the forests of the southern United States, Mexico and Central America. It has recently expanded its range to the northeastern United States, where it is considered an invasive species and has destroyed massive amounts of pine forest.
Hylastes ater is a species of beetle in the family Curculionidae, the true weevils. It is a bark beetle, a member of the subfamily Scolytinae. Its common name is the black pine bark beetle. It is native to Europe and parts of Asia, including China and Korea. It is known as an introduced species in many other regions, including Australia, New Zealand, the Americas, and South Africa. It is a pest of pines and other trees, and it is widespread in areas where pine trees are cultivated. The species "is an important threat to the biosecurity of all forested countries."
Ips is a genus of beetles in the family Curculionidae, the true weevils. They are bark beetles, members of the subfamily Scolytinae. Species are distributed throughout the Northern Hemisphere. Some are known as introduced species in Australia and Africa. Many species are pests of forest trees, especially pines and spruces. They are known commonly as engraver beetles, ips engraver beetles, and pine engravers.
Micoletzkya is a genus of predatory bark-beetle-associated nematodes in the family Diplogastridae. The genus was named for the Austrian nematologist Heinrich Micoletzky. As of 2013 it consists of 25 described species.
Menzbieria is a genus of parasitic alveolates of the phylum Apicomplexa.
Dendroctonus valens, the red turpentine beetle, is a species of bark beetle native to the forests of North America, Mexico, Guatemala and Honduras. It has been introduced to China where it has become invasive. In its native range it causes little damage, but in China it is a destructive pest and has killed more than six million pine trees.
Dendroctonus micans, the great spruce bark beetle, is a species of bark beetle native to the coniferous forests of Europe and Asia. The beetles burrow into the bark of spruce trees and lay eggs which develop into larvae that feed on the woody layers under the bark.
Rhizophagus grandis is a species of predatory beetle in the family Monotomidae. R. grandis is a specialist predator on the larvae of the great spruce bark beetle, a pest of spruce trees (Picea), and is found in Eurasian forests where its prey is found.
Dendroctonus terebrans, the black turpentine beetle, is a species of bark beetle native to the eastern United States. Its larvae tunnel under the bark of pine trees, weakening and sometimes killing the trees.
Medetera bistriata is a species of longlegged fly in the family Dolichopodidae. It is widely distributed in North America, spanning from the pine forests of boreal Canada south to Honduras, and it is common in the pine forests of the Atlantic and Gulf costal plains. The larvae are predators of bark beetles in the genera Dendroctonus and Ips, and have been noted as important predators of the southern pine beetle, Dendroctonus frontalis.
Dendroctonus brevicomis, the western pine beetle, is a species of crenulate bark beetle in the family Curculionidae. It is found in North America and parts of Mexico. It is known as a destructive pest of ponderosa and Coulter pine trees. When drought makes these pines more susceptible to infestations by D. brevicomis, there is an increased risk of forest fires due to dead trees.
Dendroctonus adjunctus, the roundheaded pine beetle, is a species of bark beetle in the family Curculionidae found in North America. A parasite, the roundheaded pine beetle feeds on and eventually kills pine trees of several species in Guatemala, Mexico, and the Southern United States.
