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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.
Amphorophora agathonica (American large raspberry aphid)
Adult apterae of Amphorophora agathonica (see first picture below) are pale green. The apical rostral segment (R IV+V) is 1.05-1.85 times the length of the second hind tarsal segment (HT II) (cf. Amphorophora sensoriata and Amphorophora rubicumberlandi, which have RIV+V 0.6-0.8 times the length of HTII). The siphunculi are pale greenish at the base, shading to dark brown towards the apices (cf. Amphoropha idaei and Amphorophora rubi, which have entirely pale siphunculi apart from a darker apical rim, and Amphorophora tigwatensa, which have the siphunculi dusky or dark). The cauda and legs are light to medium brown. The siphunculi are swollen on the distal half (cf. Aphis rubicola, which have siphunculi tapering from base to flange). The siphunculi have no zone of polygonal reticulation (cf. Illinoia rubicola, which have a sub-apical zone of polygonal reticulation). The cauda is 1.5-2.7 times R IV+V and 2.2-3.4 times the base of antennal segment VI. The body length of adult Amphorophora agathonica apterae is 2.4-4.7 mm. Immature American large raspberry aphids (see second picture below) are whitish-yellow.
Both images above by permission, copyright Claude Pilon, all rights reserved.
Amphorophora agathonica alatae have a pale brown head and thorax with a pale green abdomen.
Amphorophora agathonica feeds on the young stems and undersides of leaves of red raspberry (Rubus idaeus var. strigosus), and occasionally in small numbers on other Rubus species such as black raspberry Rubus occidentalis. These aphids do not host alternate, but remain all year on raspberry. Sexuales develop in autumn with oviparae and alate males. The species is widely distributed in North America north of about latitude 38 ° N, including Alaska and Nova Scotia. It has not been found in Europe or Asia.
Amphorophora ampullata (Dark-tipped fern aphid)
Adult apterae of Amphorophora ampullata sensu lato are green except for the eyes which are red, the siphunculi which have the distal half brown and the apices black, the tarsi and the tips of antennal segments III-VI and tibiae which are black. The characteristics given first in this section refer to Amphorophora ampullata sensu stricto, followed by comparisons with the subspecies. The terminal process is 3.5-5.2 times the length of the base of antennal segment VI (Amphorophora ampullata laingi, which has the terminal process 5.0-6.6 times the length of the base of antennal segment VI). Antennal segment III has 5-23 secondary rhinaria (cf.Amphorophora ampullata bengalensis, which has only 1-6 rhinaria near the base). The apical rostral segment (R IV+V) is 0.85-1.15 times the length of the second hind tarsal segment (HT II) (cf. Amphorophora ampullata bengalensis, which has RIV+V 1.15-1.4 times the length of HTII). The siphunculi are almost smooth, have little or no subapical reticulation, and are swollen on the distal part with maximum width about twice the narrowest width just next to the flange. The siphunculi are 1.9-2.7 times the length of the cauda (cf. Amphorophora ampullata laingi which has siphunculi 1.5-2.1 times the length of the cauda). The cauda is short and thick with 20 hairs. The body length of adult apterae of Amphorophora ampullata sensu stricto is 3.0-5.0 mm.
Both images above by permission, copyright Claude Pilon, all rights reserved.
Amphorophora ampullata feeds on the frond undersides of ferns in a number of genera (e.g. Asplenium, Athyrium, Cystopteris, Dryopteris, Onoclea, Polypodium, Polystichum). It does not host alternate, remaining all year on ferns. Sexual forms with alate males develop in autumn, and the population overwinters in the egg stage. Amphorophora ampullata is found in Europe, Asia and North America.
Amphorophora gei (Water avens aphid)
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.
Amphorophora idaei (Large raspberry aphid)
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.
Amphorophora rubi (Large blackberry aphid)Amphorophora rubi apterae are pale green or yellowish green with pale siphunculi. Their antennal terminal process is usually less than seven times the length of last two segments of the rostrum. The third antennal segment bears 2-44 rhinaria with its longest hairs 26-48 µm (cf. Amphorophora gei which has the longest hairs on the third antennal segment 17-30 µm long). The siphunculi are slightly swollen on the apical part and 2.1 to 2.4 times the length of the cauda. The cauda is triangular. The body length of Amphorophora rubi apterae is 2.2-4.7 mm.
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.