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Aphididae : Aphidinae : Macrosiphini : Decorosiphon


Genus Decorosiphon

Decorosiphon aphids

On this page: Decorosiphon corynothrix

Decorosiphon [Macrosiphini]

Decorosiphon are small, oval, moss-feeding aphids characterised by long, stiff, erect hairs on the body, antennae and legs. The frons is low, broad, coarsely granulate, with diverging antennal tubercles and a lower median frontal tubercle. The antennae are 6-segmented and longer than the body. Antennal segment I has a low conical hair-bearing process on the inner side, and the terminal process is pointed. The first tarsal segment has 3-3-2 hairs (fore-mid-hind). The stigmata are reniform (=kidney-shaped). Marginal tubercles on thorax and abdomen are absent. The siphunculi are longer than the cauda, markedly swollen on the distal half, and with a large flange. The cauda has the basal part broad, and the distal part slender, much like most other moss-feeding aphids.

Alatae have a large, dark dorsal abdominal patch.

There is only one species worldwide in the Decorosiphon genus, Decorosiphon corynothrix feeding on mosses, especially the hair cap moss (Polytrichum commune), in Europe & North America.


Decorosiphon corynothrix (Long-haired moss aphid) Europe, Eastern North America

Adult apterae of Decorosiphon corynothrix (see middle aphid in first picture below, and reddish brown aphid in second picture) are shiny olive, brownish yellow or reddish brown. The cuticle of the metanotum, and abdominal tergites I-V are fused into a sclerotic, but rather pale carapace. The antennae are 1.1-1.3 times the body length, with a terminal process that is about 2.6-2.9 times the base of antennal segment VI. Secondary rhinaria are distributed 0-1 on segment III, 0-12 on segment IV and none on segment V. Hairs on body and appendages are very long, with a spatulate distal part (cf. Pseudacaudella rubida and Myzodium spp., which have normal length hairs) The rostrum reaches behind the hind coxae, with the apical rostral segment (RIV+V) 1.5-1.6 times the second hind tarsal segment (HTII). The siphunculi have a subapical constriction and a well-developed apical flange (cf. Muscaphis musci, which has siphunculi with no subapical contriction, or flange). The siphunculi are strongly swollen distally to about twice their basal diameter, and are 2.3-3.1 times the caudal length. The cauda has a broad basal part and a slender distal part. Adult apterae of Decorosiphon corynothrix have a body length of 1.2-1.7 mm. Immatures (see left and right hand aphids in first picture above) are green to olive brown, with whitish wax dusting. The rupture lines in the cuticle which break at moulting are often very distinct, due to a denser wax coating.

First image above copyright Anders Albrecht, second image above copyright Henk Soepenberg,
both under a Creative Commons Attribution 3.0 License.

The alate Decorosiphon corynothrix has about 47 secondary rhinaria on antennal segment III, 27 on segment IV and about 18 on segment V.

Decorosiphon corynothrix is monoecious on mosses, seeming to prefer species in the Polytrichaceae, especially the common haircap moss (Polytrichum commune). Other hosts include Polytrichum juniperinum & Polytrichum strictum, and also Rhytidiadelphus squarrosus in the Hylocomiaceae. It is found in peat bogs, and in damp places in coniferous and deciduous forests. It is often on Polytrichum interspersed in Sphagnum tussocks. The species is anholocyclic. Both adults and immmatures can be found all the year. It is not attended by ants. The long-haired moss aphid is found in Europe and in eastern North America.



We are grateful to Anders Albrecht, and Henk Soepenberg, for permitting us to use their images, both under a Creative Commons Attribution 3.0 License.

We have used the keys and species accounts of Heie (1992), together with those of Roger Blackman & Victor Eastop in Aphids on Worlds Plants. We fully acknowledge these authors (see references below) as the source for the (summarized) taxonomic information we have presented. Any errors in identification or information are ours alone, and we would be very grateful for any corrections. For assistance on the terms used for aphid morphology we suggest the figure provided by Blackman & Eastop (2006).

Useful weblinks


  • Heie, Ole E. (1992). The Aphidoidea (Hemiptera) of Fennoscandia and Denmark. IV. Family Aphididae: Part I of tribe Macrosiphini and subfamily Aphidinae. Fauna Entomologica Scandinavica 25, 1-189 (p. 106).