Beech Blight Aphids - Flickr - treegrow (8)

Woolly aphids (subfamily: Eriosomatinae) are

sap Sap is a fluid transported in xylem cells (vessel elements or tracheids) or phloem sieve tube elements of a plant. These cells transport water and nutrients throughout the plant. Sap is distinct from latex, resin, or cell sap; it is a separ ...

-sucking

insect Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three ...

s 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. Woolly aphids occur throughout the Northern Hemisphere. Many of the numerous species of woolly aphids have only one host plant species, or alternating generations on two specific hosts. They have been known to cause botanical damage and are often considered a pest. While most damage is minor, they can spread plant diseases and fungi. Some species can produce galls as well. In flight they have been described as looking like "flying mice." Other nicknames include "angel flies", “cotton fairies”, "fluff bugs", "fairy flies", "ash bugs", "snow bugs", "fluffer fairies", "poodle flies", and "fluffy gnats".

Diet

Woolly aphids feed by inserting their needle-like mouthparts into plant tissue to withdraw sap. They are able to feed on leaves, buds, bark, and even the roots of the plant. As a result of feeding on the sap, woolly aphids produce a sticky substance known as honeydew, which can lead to sooty mold on the plant.

Botanical damage

Woolly aphids generally are not much cause for alarm, although they can cause rather unsightly damage to plants, which is particularly a problem for growers of ornamental plants. Symptoms caused by their feeding on a plant include twisted and curled leaves, yellowed foliage, poor plant growth, low plant vigor, and branch dieback. The woolly apple aphid, ''

Eriosoma lanigerum ''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. Description The adults of ''Eriosoma lanigerum'' ar ...

'' is a widespread pest of fruit trees, feeding principally on apple, but also, pears, hawthorn, ash, alders, elms and oak

Gall making species include ''

Melaphis rhois ''Melaphis rhois'' is an aphid species first identified by Asa Fitch in 1866. Known as the staghorn sumac aphid, it is the only species in the genus ''Melaphis''. It is a type of wooly aphid, woolly aphid and one of the few aphids that induce th ...

and'' ''

Pemphigus Pemphigus ( or ) is a rare group of blistering autoimmune diseases that affect the skin and mucous membranes. The name is derived from the Greek root ''pemphix'', meaning "pustule". In pemphigus, autoantibodies form against desmoglein, whi ...

'' spp. Further minor damage can be caused by the honeydew that woolly aphids secrete, which is difficult to remove. While the honeydew itself doesn't cause too much of a problem, the honeydew can cause sooty mold to grow, which can block some of the sunlight needed for

photosynthesis Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's activities. Some of this chemical energy is stored i ...

. Woolly aphids and other sucking insects are often vectors of transmission for

powdery mildew Powdery mildew is a fungal disease that affects a wide range of plants. Powdery mildew diseases are caused by many different species of ascomycete fungi in the order Erysiphales. Powdery mildew is one of the easier plant diseases to identify, a ...

(a white

fungus A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from t ...

which grows on above ground parts of some plants), and other infectious diseases. Typically wooly aphids in subtemperate climates precede and are an indicator of various plant

infection An infection is the invasion of tissues by pathogens, their multiplication, and the reaction of host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmissible disease or communicable dis ...

s, including powdery mildew. Aphids penetrate plant surfaces where they often reside and provide a host of potential inoculants through physical, digestive or

fecal Feces ( or faeces), known colloquially and in slang as poo and poop, are the solid or semi-solid remains of food that was not digested in the small intestine, and has been broken down by bacteria in the large intestine. Feces contain a relati ...

secretions. Aphids are often an indicator of other potential plant problems.

Taxonomy

The subfamily Eriosomatinae has recently been placed within the family

Aphididae The Aphididae are a very large insect family in the aphid superfamily ( Aphidoidea), of the order Hemiptera. These insects suck the sap from plant leaves. Several thousand species are placed in this family, many of which are considered plant/crop ...

. It was previously placed in family Pemphigidae = Eriosomatidae, but that taxon is no longer valid.

Tribes and genera

Tribe: Eriosomatini

'' Americanum'' - '' Aphidounguis'' - '' Byrsocryptoides'' - '' Colopha'' - '' Colophina'' - '' Eriosoma'' - '' Gharesia'' - '' Hemipodaphis'' - '' Kaltenbachiella'' - '' Paracolopha'' - '' Schizoneurata'' - '' Schizoneurella'' - '' Siciunguis'' - '' Tetraneura'' - '' Zelkovaphis''

Tribe: Fordini

'' Aloephagus'' - '' Aploneura'' - '' Asiphonella'' - '' Baizongia'' - '' Chaetogeoica'' - '' Dimelaphis'' - '' Forda'' - '' Geoica'' - '' Geopemphigus'' - '' Kaburagia'' - '' Melaphis'' - '' Nurudea'' - '' Paracletus'' - '' Rectinasus'' - '' Schlechtendalia'' - '' Slavum'' - '' Smynthurodes'' - '' Tramaforda''

Tribe: Pemphigini

'' Ceratopemphigiella'' - '' Ceratopemphigus'' - '' Clydesmithia'' - '' Cornaphis'' - '' Diprociphilus'' - '' Epipemphigus'' - '' Formosaphis'' - '' Gootiella'' - '' Grylloprociphilus'' - '' Mimeuria'' - '' Mordwilkoja'' - '' Neopemphigus'' - '' Neoprociphilus'' - '' Pachypappa'' - '' Pachypappella'' - '' Patchiella'' - ''

'' - '' Prociphilus'' - '' Thecabius'' - '' Tiliphagus'' - '' Uichancoella''

References

{{Taxonbar, from=Q846666 Agricultural pest insects Hemiptera subfamilies