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Berry aphidsOn this page: Genus Amphorophora Amphorophora gei Amphorophora idaei Amphorophora rubi
Genus Amphorophora [Macrosiphini]
Amphorophora are medium-sized to large rather pale greenish aphids. Adult viviparae may be winged or wingless. The body is elongate or oval, with long legs and antennae, the latter longer than body. Their antennal tubercles are well developed, with the inner margins nearly straight and distinctly divergent. The median frontal tubercle is less well developed. The siphunculi are long, distinctly but usually only slightly swollen on apical half, with a clearly marked apical flange, and no polygonal reticulation. The cauda is not very elongate, and somewhat blunt at its apex.
There are about 27 species of Amphorophora aphids, mostly in North America but with some in Europe and Asia. They have a sexual stage in the life cycle. They do not host alternate and feed on the leaves and stems of berries (Rubus spp., Rosaceae) or ferns. They are not attended by ants. Some species are important soft-fruit pests.
Adult apterae of Amphorophora gei are deep yellow to pale green with dusky swollen siphunculi and a thick cauda (see pictures below) (cf. Acyrthosiphon malvae ssp. potha which is yellowish or greyish green, but does not have swollen siphunculi). The antennae are about 1.2 times the body length, with the terminal process of antennal segment 6 about 5.0-7.1 times the length of the base of that segment. Antennal segment III has 1-10 secondary rhinaria with its longest hairs 17-30 μm long. Marginal tubercles are usually absent from the abdomen. The siphunculi are about 2.3-3.1 times the length of the cauda with the swollen apical part nearly twice as thick as the basal part. The cauda is thick, with 7-9 hairs. The adult body length of of Amphorophora gei apterae is 2.2-3.9 mm.
Both images above copyright Alan Watson Featherstone all rights reserved.
Alate Amphorophora gei have the abdomen green with small marginal sclerites and narrow, not very dark, cross bands on the anterior part. Each antenna has 19-32 secondary rhinaria on segment III in a row over its whole length.
Amphorophora gei is most commonly found on the undersides of the leaves of water avens (Geum rivale) in moist shady places, although it does also occur on other Geum species. Sexual forms are thought to occur in autumn with overwintering eggs laid on Geum. The water avens aphid is found infrequently in Britain, but is widespread in continental Europe, and has been introduced to the USA.
The large raspberry aphid (Amphorophora idaei) only feeds on raspberry and the apterae (see first picture below) are usually greenish white or pale yellow (cf. Amphorophora rubi which is darker green and feeds on blackberry). The antennal terminal process is usually more than seven times the length of the last two segments of the rostrum. The siphunculi are slightly swollen on the apical part and 2.1 to 2.6 times the length of the cauda. The cauda is short and triangular. The body length of Amphorophora idaei apterae is 2.7-4.1 mm.
The alate Amphorophora idaei (see second picture above) is of similar size but has a brown head and thorax, and has the distal half of the siphunculi darkened.
The large raspberry aphid has a sexual stage in its life cycle and does not host alternate. Oviparae and winged males appear in October-November. Amphorophora idaei feeds on the underside of leaves of raspberry (Rubus idaei) and is found throughout Europe.
The alate Amphorophora rubi has the marginal sclerites indistinct or absent, and the siphunculi are dusky.
The large blackberry aphid does not host alternate. It feeds on the underside of leaves of blackberry (Rubus fruticosus agg.) and related Rubus species, but not on raspberry (Rubus idaei). Amphorophora rubi is found throughout Europe and has been introduced to New Zealand.