''Cinara confinis'', the black stem aphid, is a

species In biology, a species is the basic unit of Taxonomy (biology), classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of ...

aphid 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 ...

in the genus ''

Cinara ''Cinara'', the conifer aphids or giant conifer aphids, is a genus of aphids in the family Aphididae. They are widespread in the Northern Hemisphere. These aphids specialize on conifers in the pine and cypress families.Jousselin, E., et al ...

'', found feeding on the twigs of various species of

fir Firs (''Abies'') are a genus of 48–56 species of evergreen coniferous trees in the family Pinaceae. They are found on mountains throughout much of North and Central America, Europe, Asia, and North Africa. The genus is most closely related to ...

(''Abies'') and on several other species of coniferous trees. This aphid has a

Holarctic The Holarctic realm is a biogeographic realm that comprises the majority of habitats found throughout the continents in the Northern Hemisphere. It corresponds to the floristic Boreal Kingdom. It includes both the Nearctic zoogeographical regi ...

distribution and is known from Europe, Asia, North America and Argentina.

Description

''Cinara confinis'' is a dark-coloured aphid growing to a maximum length of about . The head and thorax are dark brown with yellowish-grey antennae and dark brown-ringed or blackish limbs. The abdomen is greenish-black or dark brown with two longitudinal rows of shining black spots and specks of wax in transverse rows. The

cornicle The cornicle (or siphuncule) is one of a pair of small upright backward-pointing tubes found on the dorsal side of the 5th or 6th abdominal segments of aphids. They are sometimes mistaken for cerci. They are no more than pores in some species. ...

s (upright tubes found on the last abdominal segment) are prominent and dark-coloured.

Hosts

''Cinara confinis'' has been found feeding on species of

(''Abies''), and also on

cedar Cedar may refer to: Trees and plants *''Cedrus'', common English name cedar, an Old-World genus of coniferous trees in the plant family Pinaceae *Cedar (plant), a list of trees and plants known as cedar Places United States * Cedar, Arizona * ...

(''Cedrus''), spruce (''Picea'') and

juniper Junipers are coniferous trees and shrubs in the genus ''Juniperus'' () of the cypress family Cupressaceae. Depending on the taxonomy, between 50 and 67 species of junipers are widely distributed throughout the Northern Hemisphere, from the Arcti ...

(''Juniperus''). It has a

distribution and is found in temperate regions of Europe and Asia, in North America and Argentina. Fir trees were introduced into the United Kingdom in the 17th century, and ''C. confinis'' may have been introduced at the same time.

Biology

Maine Maine () is a U.S. state, state in the New England and Northeastern United States, Northeastern regions of the United States. It borders New Hampshire to the west, the Gulf of Maine to the southeast, and the Provinces and territories of Canad ...

, wingless females known as fundatrices hatch out of over-wintering eggs in mid-May, at the base of buds near the top of small trees. Colonies form just below the first whorl of shoots and the reproduction at first is

parthenogenetic Parthenogenesis (; from the Greek grc, παρθένος, translit=parthénos, lit=virgin, label=none + grc, γένεσις, translit=génesis, lit=creation, label=none) is a natural form of asexual reproduction in which growth and developmen ...

and

viviparous Among animals, viviparity is development of the embryo inside the body of the parent. This is opposed to oviparity which is a reproductive mode in which females lay developing eggs that complete their development and hatch externally from the ...

with the offspring being wingless. If disturbed, adults drop to the ground but nymphs move rapidly away on the trunk. Colonies are transitory, and by mid-June, most colonies are at the base of trees, at the root collar or on the roots. Some winged females then occur and colonies develop on the roots and root collars of nearby trees. By October, winged males are also produced, and they and winged females move to near the top of the trees where eggs are laid in crevices in the bark. Colonies of this aphid are often attended by ants such as the southern wood ant (''Formica rufa'') which feed on the honeydew produced by the aphids. Sometimes the ants construct earth galleries to enclose the aphid colony. The ants also protect the aphids from

parasitic wasps Parasitoid wasps are a large group of hymenopteran superfamilies, with all but the wood wasps ( Orussoidea) being in the wasp-waisted Apocrita. As parasitoids, they lay their eggs on or in the bodies of other arthropods, sooner or later cau ...

; however, some aphids are still

parasitized Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson has ...

, and become blackish,

mummified A mummy is a dead human or an animal whose soft tissues and organs have been preserved by either intentional or accidental exposure to chemicals, extreme cold, very low humidity, or lack of air, so that the recovered body does not decay fu ...

husks. The wasp ''

Pauesia grossa ''Pauesia grossa'' is a species of parasitoid wasp in the subfamily Aphidiinae. It is specific to a particular host, the black stem aphid (''Cinara confinis''), which feeds on the sap of coniferous trees, particularly firs (''Abies''). ''Pauesi ...

'', found in Central Europe, is probably restricted to using ''Cinara confinis'' as a host in which to lay eggs.

References

{{Taxonbar, from=Q10453011 Lachninae Insects described in 1856 Hemiptera of North America