Aphids are small sap-sucking insects and members of the superfamily Aphidoidea. Common names include greenfly and blackfly, although individuals within a species can vary widely in color. The group includes the fluffy white woolly aphids. A typical life cycle involves flightless females giving live birth to female nymphs—who may also be already pregnant, an adaptation scientists call telescoping generations—without the involvement of males. Maturing rapidly, females breed profusely so that the number of these insects multiplies quickly. Winged females may develop later in the season, allowing the insects to colonize new plants. In temperate regions, a phase of sexual reproduction occurs in the autumn, with the insects often overwintering as eggs.
A spruce is a tree of the genus Picea, a genus of about 40 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.
Galls or cecidia are a kind of swelling growth on the external tissues of plants. 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 insect and mite plant galls. The study of plant galls is known as cecidology.
A conifer cone or pinecone is a seed-bearing organ on gymnosperm plants. It is usually woody, ovoid to globular, including scales and bracts arranged around a central axis, especially in conifers and cycads. The cone of Pinophyta contains the reproductive structures. The woody cone is the female cone, which produces seeds. The male cone, which produces pollen, is usually herbaceous and much less conspicuous even at full maturity. The name "cone" derives from Greek konos, which also gave name to the geometric cone. The individual plates of a cone are known as scales. The umbo of a conifer cone refers to the first year's growth of a seed scale on the cone, showing up as a protuberance at the end of the two-year-old scale.
Tsuga canadensis, also known as eastern hemlock, eastern hemlock-spruce, or Canadian hemlock, and in the French-speaking regions of Canada as pruche du Canada, is a coniferous tree native to eastern North America. It is the state tree of Pennsylvania. Eastern hemlocks are widespread throughout much of the Great Lakes region, the Appalachian Mountains, the Northeastern United States, and Maritime Canada. They have been introduced in the United Kingdom and mainland Europe, where they are used as ornamental trees.
The blue spruce, also commonly known as Colorado spruce or Colorado blue spruce, is a species of spruce tree native to North America in Arizona, Colorado, Idaho, New Mexico, Utah and Wyoming. It is noted for its blue-green colored needles, and has therefore been used as an ornamental tree in many places far beyond its native range.
Woolly aphids are sap-sucking insects that produce a filamentous waxy white covering which resembles cotton or wool. The adults are winged and move to new locations where they lay egg masses. The nymphs often form large cottony masses on twigs, for protection from predators.
Adelges tsugae, the hemlock woolly adelgid or HWA, is an insect of the order Hemiptera native to East Asia. It feeds by sucking sap from hemlock and spruce trees. In its native range, HWA is not a serious pest because populations are managed by natural predators and parasitoids and by host resistance. In eastern North America it is a destructive pest that threatens the eastern hemlock and the Carolina hemlock. HWA is also found in western North America, where it has likely been present for thousands of years. In western North America, it primarily attacks western hemlock Tsuga heterophylla and has only caused minor damage due to natural predators and host resistance. Accidentally introduced to North America from Japan, HWA was first found in the eastern United States near Richmond, Virginia, in 1951. The pest is now found from northern Georgia to coastal Maine and southwestern Nova Scotia as well as areas of western Michigan near the eastern Lake Michigan shoreline. As of 2015, HWA has affected 90% of the geographic range of eastern hemlock in North America.
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.
The Adelgidae are a small family of the Hemiptera closely related to the aphids, and often included in the Aphidoidea with the Phylloxeridae or placed within the superfamily Phylloxeroidea as a sister of the Aphidoidea within the infraorder Aphidomorpha. The family is composed of species associated with pine, spruce, or other conifers, known respectively as "pine aphids" or "spruce aphids". This family includes the former family Chermesidae, or "Chermidae", the name of which was declared invalid by the ICZN in 1955. There is still considerable debate as to the number of genera within the family, and the classification is still unstable and inconsistent among competing authors.
Pine and fir trees, grown purposely for use as Christmas trees, are vulnerable to a wide variety of pests, weeds and diseases. Many of the conifer species cultivated face infestations and death from such pests as the balsam woolly adelgid and other adelgids. Aphids are another common insect pest. Christmas trees are also vulnerable to fungal pathogens and their resultant illnesses such as root rot, and, in the U.S. state of California, sudden oak death. Douglas-fir trees in particular are vulnerable to infections from plant pathogens such as R. pseudotsugae.
Pissodes strobi, known as the white pine weevil or Engelmann spruce weevil, is the primary weevil attacking and destroying white pines. It was described in 1817 by William Dandridge Peck, professor of natural history and botany at Harvard University. The weevil is dark brown with white spots and is native to North America.
Cinara cupressi, the cypress aphid, is a brownish soft-bodied aphid. It sucks sap from twigs of conifers, and can cause damage to the tree, ranging from discoloring of the affected twig to the death of the tree. This insect appears to have originated in the Middle East and has been increasing its range and is considered to be an invasive species in Africa and Europe. It has been included in the List of the world's 100 worst invasive species.
The balsam woolly adelgid is small wingless insect that infests and kills firs. In their native Europe they are a minor parasite on silver fir and Sicilian fir, but they have become a threat especially to balsam fir and Fraser fir after they were introduced to the United States around the beginning of the 20th century. Because this species is not native to North America, the Fraser fir has not evolved any type of defense against it.
Adelges is a genus of insects which feed on conifers. They have complex life cycles, some species feeding exclusively on spruce, others feeding on spruce and an alternate conifer. However, galls characteristic of each species are formed only on spruce. Six generations are usually needed to complete the 2-year cycle, and in the case of species having an alternate host, winged adults about 2 mm long are formed only in the generations that move from one host to the other.
Pemphigus betae, also known as the sugarbeet root aphid, is a species of gall-forming aphid that forms galls specifically on the commonly found narrowleaf cottonwood, Populus angustifolia. Sugarbeet root aphids have been found in North America and Europe. They infect sugarbeets, but also other plants like tablebeets and Swiss chard. Their size has been likened to that of a pinhead, and are pale white-yellow in color. Sugarbeet root aphids have soft bodies that are bulbous in shape, with mandibular parts that can pierce and suck and paired abdominal tubes that point backwards, and come in both winged and wingless forms. They are known for their consequential effects on agriculture due to infestation of plants, and efforts to control the pests have proved to be difficult.
Phylloxeridae is a small family of plant-parasitic hemipterans closely related to aphids with only 75 described species. This group comprises two subfamilies and 11 genera with one that is fossil. The genus type is Phylloxera. The Phylloxeridae species are usually called phylloxerans or phylloxerids.
Eriosoma lanigerum, the woolly apple aphid, woolly aphid or American blight, is an aphid in the superfamily Aphidoidea in the order Hemiptera. It is a true bug and sucks sap from plants.
Elatobium abietinum, commonly known as the spruce aphid or green spruce aphid, is a species of aphid in the subfamily Aphidinae that feeds on spruce, and occasionally fir. It is native to Northern, Central and Eastern Europe and has spread to Western Europe, North America and elsewhere.
Nalepella, the rust mites, is a genus of very small Trombidiform mites in the family Phytoptidae. They are commonly found on a variety of conifers, including hemlock, spruce, balsam fir, and pine. They sometimes infest Christmas trees in nurseries. Nalepella mites are vagrants, meaning they circulate around the tree; females overwinter in bark cracks. Infested spruce emit a characteristic odour.
