Pineus

Shimer, 1869

Pineus is a of ( Adelgidae) comprising more than 20 described . These are small, sap-feeding specialized on conifer , primarily Pinus (pines) and Picea (spruces). Species exhibit complex with multiple morphological forms, including winged and wingless , and some alternate between two host species. Several species are economically significant as pests of forestry and ornamental plantings.

Pineus strobi by no rights reserved, uploaded by Lynn Harper. Used under a CC0 license.

Pineus strobi by (c) Summit Metro Parks, some rights reserved (CC BY), uploaded by Summit Metro Parks. Used under a CC-BY license.

Annual report of the Commissioners of Fisheries, Game and Forests of the State of New York" (1896-1900)) (19176028240) by Internet Archive Book Images. Used under a No restrictions license.

Pronunciation

How to pronounce Pineus: /ˈpɪnaɪəs/

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Identification

in the Pineus are distinguished from related adelgids (Adelges) by having four abdominal . They are small, soft-bodied with . Winged forms (gallicolae) possess two pairs of , while wingless forms (sistentes, neosistentes, ) are oval to pear-shaped and often covered with woolly secretions. First- () are the stage and possess functional legs; subsequent instars of wingless females become .

Images

Habitat

Coniferous forests and ornamental plantings; associated with trees in the Pinus and Picea. Some induce formation on spruce shoots, while others feed on bark or needles without gall formation.

Distribution

Widespread in the Northern Hemisphere. to North America, Europe, and Asia. Specific distributions vary by : P. similis in Colorado and Maine; P. floccus in eastern North America; P. pineoides in Europe and to eastern Canada; P. orientalis in Ukraine; P. strobi recorded in Fergana Valley, Central Asia.

Diet

Phloem sap of conifer . All feed exclusively on Pinaceae, with most specialized on Pinus (pines) and/or Picea (spruces).

Host Associations

Pinus strobus - Eastern pine; primary or for multiple
Pinus resinosa - Red pine; for P. coloradensis and P. boerneri
Pinus taeda - Loblolly pine; for P. boerneri
Pinus elliottii - Slash pine; preferred for P. boerneri
Picea pungens - spruce; for P. similis
Picea glauca - spruce; preferred for P. similis
Picea rubens - Red spruce; for P. similis and P. pineoides
Picea mariana - Black spruce; for P. similis
Picea abies - Norway spruce; for P. similis

Life Cycle

Complex with multiple parthenogenetic and typically one sexual generation. Most have at least five distinct morphological forms: (stem mother), gallicola (-former on spruce), sistentes and neosistentes (wingless feeding stages on pine), and (sexual forms). Some species alternate between spruce (primary , where galls form) and pine (secondary host); others complete their entire cycle on a single host . P. pineoides is exceptional in completing its life cycle on spruce without producing galls or winged forms. Development from to ranges from approximately 65–70 days under laboratory conditions.

Behavior

First- () are the only mobile stage in wingless ; they disperse to new growth or new via wind, birds, mammals, or human activity. Winged gallicolae from spruce to pine to initiate new generations. Some are non-migrating. Dense populations produce woolly secretions.

Ecological Role

that can cause significant damage to trees through direct feeding, formation, and associated stress. Heavy cause needle stunting, shoot deformation, reduced growth, and tree decline. production can lead to growth, further impairing . include , ( on ), the Laetilia coccidivora (predator on ), and such as Coccophagus lycimnia.

Human Relevance

Several are economically important forest and ornamental pests. P. pinifoliae, P. boerneri, P. coloradensis, and P. floccus cause damage to pine and spruce in forestry and urban settings. P. orientalis is an pest in Ukraine. reduce aesthetic value of ornamental trees, impair growth, and can kill stressed trees. Management involves and targeted .

Similar Taxa

AdelgesOther in ; distinguished by having six abdominal versus four in Pineus
Toumeyella of () also found on pines; distinguished by being with hardened coverings rather than mobile with woolly