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American juniper aphid, Large juniper aphidOn this page: Identification & Distribution Other aphids on the same host
Identification & Distribution
Adult apterae of Cinara fresai (see pictures below) are pinkish-grey to dark brownish-grey or greenish-grey. They are dusted with white wax down the midline and laterally, quite thickly on the thoracic segments but less heavily on the abdominal segments. They have paired black patches on thoracic and anterior abdominal tergites diverging in an inverted "V". The body and appendages are clothed with long pale hairs. The base of antennal segment VI has 7-12 hairs not restricted to the basal half (cf. Cinara cupressi which has 4-7 hairs restricted to the basal half ). Rostral segment IV has 5-7 accessory hairs (see micrograph below) (cf. Cinara cupressi which has 2-4 hairs on RIV). The distal parts of the hind femora are dusky or dark (cf. Cinara tujafilina which has hind femora pale). The bases and apices of the hind tibiae are dusky or dark but with a paler area in between (cf. Cinara juniperi which has the hind tibiae uniformly dark). The body length of adult Cinara fresai apterae is 2.2-4.2 mm.
The alate Cinara fresai (not pictured) is unusual in having the radial sector not reaching the apex of the forewing. The abdominal pattern is reduced in comparison to the aptera.
The micrographs below show an adult aptera of Cinara fresai, dorsal and ventral, and rostral segments RIV and RV, with 5-6 accessory hairs on RIV.
Cinara fresai feeds on the needles and adjacent woody shoots and branches of various Cupressaceae, especially junipers (Juniperus chinensis, Juniperus sabina, Juniperus squamata and Juniperus virginiana and their cultivated varieties), but not apparently in Europe on the native common juniper (Juniperus communis). Cinara fresai has also been reported on some Cupressus species. Reproduction is entirely parthenogenetic. No sexual forms have ever been found. It is sometimes attended by ants. As with Cinara cupressi large infestations can lead to the development of sooty mould and blackening of shoots, and can cause diebacks of shoots and death of trees. Cinara fresai presumably got its common name (American juniper aphid) from its presence on Juniperus virginiana, but its other preferred hosts suggest it is may be native to the Far East rather than America, and has been spread worldwide by the plant trade. It has been recorded from Japan, Korea, Australia, New Zealand, England & Wales, Poland, Spain, Israel, USA, Central and South America.
Other aphids on the same host
Cinara fresai has been recorded from 11 Juniperus species and 8 Cupressus species.
Blackman & Eastop list 28 species of aphid as feeding on juniper (Juniperus spp) worldwide, and provide formal identification keys (Show World list). Of those aphid species, Baker (2015) lists 7 as occurring in Britain (Show British list).
Blackman & Eastop list 9 species of aphid as feeding on cypresses (Cupressus species) worldwide, and provide formal identification keys (Show World list). Of those aphid species, Baker (2015) lists 5 as occurring in Britain (Show British list).