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 20–60 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.
Galls or cecidia are a kind of swelling growth on the external tissues of plants, fungi, or animals. Plant galls are abnormal outgrowths of plant tissues, similar to benign tumors or warts in animals. They can be caused by various parasites, from viruses, fungi and bacteria, to other plants, insects and mites. Plant galls are often highly organized structures so that the cause of the gall can often be determined without the actual agent being identified. This applies particularly to some insect and mite plant galls. The study of plant galls is known as cecidology.
Picea glauca, the white spruce, is a species of spruce native to the northern temperate and boreal forests in North America. Picea glauca was originally native from central Alaska all through the east, across southern/central Canada to the Avalon Peninsula in Newfoundland. It now has become naturalized southward into the far northern United States border states like Montana, Minnesota, Wisconsin, Michigan, Vermont, New Hampshire and Maine; there is also an isolated population in the Black Hills of South Dakota and Wyoming. It is also known as Canadian spruce, skunk spruce, cat spruce, Black Hills spruce, western white spruce, Alberta white spruce, and Porsild spruce.
The blue spruce, also commonly known as green spruce, white spruce, Colorado spruce, or Colorado blue spruce, is a species of spruce tree. It is native to North America, and is found in USDA growing zones 1 through 7. Its natural range extends from northern New Mexico through Colorado and Utah to Wyoming and into Alberta and British Columbia, but it has been widely introduced elsewhere and is used as an ornamental tree in many places far beyond its native range. The blue spruce has blue-green colored needles and is a coniferous tree.
Cecidomyiidae is a family of flies known as gall midges or gall gnats. As the name implies, the larvae of most gall midges feed within plant tissue, creating abnormal plant growths called galls. Cecidomyiidae are very fragile small insects usually only 2–3 mm (0.079–0.118 in) in length; many are less than 1 mm (0.039 in) long. They are characterised by hairy wings, unusual in the order Diptera, and have long antennae. Some Cecidomyiids are also known for the strange phenomenon of paedogenesis in which the larval stage reproduces without maturing first. In some species, the daughter larvae consume the mother, while in others, reproduction occurs later on in the egg or pupa.
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.
Cydia strobilella, the spruce seed moth, is a moth of the family Tortricidae. It is found in Europe.
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.
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, 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.
Coleotechnites piceaella is a moth of the family Gelechiidae. It is found in north-eastern United States and Canada. It is an introduced species in Europe and was first recorded from Great Britain in 1952, then Germany in 1963 and has expanded from there over all of central Europe, towards France, Italy and Hungary.
Dasineura crataegi, the hawthorn button-top gall-midge, is a dipteran gall-midge. It causes the hawthorn button-top gall, which develops in the terminal shoots of common hawthorn, Crataegus monogyna Jacq., Midland hawthorn C laevigata (Poir.) DC and their hybrid, C × media Bechst. Synonyms are Perrisia crataegi and Cecidomyia crataegi.
Synanthedon pini, the pitch mass borer, is a moth of the family Sesiidae. The pitch mass borer occurs on spruce and pine in eastern North America. It does not kill trees, but the pitch-filled larval tunnels in the wood cause defects in the lumber.
The Pineapple gall adelgid is a type of conifer-feeding insect that forms pineapple-shaped plant galls on its host species, commonly Norway and Sitka spruce. The adelgids are pear-shaped, soft-bodied green insects with long antennae, closely related to the aphid. "Adelges" lays up to one hundred eggs at a time, one on each needle. Adelges abietis is one of the most common species; synonyms are A. gallarum-abietis, Chermes abietis and Sacciphantes abietis.
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".
Argyresthia picea is a moth of the family Yponomeutidae. It is found in Canada, including Alberta, Ontario, Quebec and the Yukon.
Orseolia oryzae, also called the Asian rice gall midge, is a species of small fly in the family Cecidomyiidae. It is a major insect pest of rice. The damage to the crop is done by the larvae which form galls commonly known as "silver shoots" or "onion shoots". The rice plant is stunted and the seed heads fail to develop.
Megastigmus atedius is a species of minute wasp that feeds on white spruce seed and cones. The damage it causes is largely undetected because the larvae complete their development hidden inside the seeds, which reveal no external indication of this. Although species of Megastigmus are said to be host-specific, the spruce seed chalcid found near Fairbanks, Alaska, was identified by E.H. Holsten and others in 1980 as M. piceae, while A.H. Rose and O.H. Lindquist applied the name Megastigmus piceae, but gave the authority as Rohwer.
Gilpinia hercyniae, the European spruce sawfly, was first found in North America near Hull, Quebec, in 1922. By 1930, severe damage was occurring in spruce stands in the Lower St. Lawrence–Gaspé region of Quebec. Population levels exploded, and further damage subsequently occurred in New Brunswick and the northeastern United States. Loss of wood from spruce mortality was estimated at 10 million cubic metres, but by the mid-1980s pest numbers on all species of spruce in Canada from Manitoba to the Atlantic Ocean and in adjacent parts of the United States had become relatively low under the influence of spontaneous virus disease and introduced parasites. In Newfoundland, control was helped by the introduction of the masked shrew, a cocoon-hunting insectivore.
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.
A gnat is any of many species of tiny flying insects in the dipterid suborder Nematocera, especially those in the families Mycetophilidae, Anisopodidae and Sciaridae. They can be both biting and non-biting. Most often they fly in large numbers, called clouds. "Gnat" is a loose descriptive category rather than a phylogenetic or other technical term, so there is no scientific consensus on what constitutes a gnat. Some entomologists consider only non-biting flies to be gnats. Certain universities and institutes also distinguish eye gnats: the Smithsonian Institution describes them as "non-biting flies, no bigger than a few grains of salt, ... attracted to fluids secreted by your eyes".
