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Green salmonberry aphidOn this page: Identification & Distribution Other aphids on the same host
Identification & Distribution
Adult apterae of Amphorophora forbesi (see picture below) are shiny light green, sometimes with darker green patches spinally and marginally. The apices of their tibiae and siphunculi are light brown. The head is spiculose only ventrally (cf. Illinoia maxima, where the head lacks spicules; and cf. Myzus persicae, where the head is densely spiculose dorsally and ventrally). The antennal tubercles are steep sided and slightly scabrous, and there is a low median frontal tubercle. The antennae are slightly shorter than the body, darkened towards the apices and without secondary rhinaria. The antennal terminal process is 3.8-7.2 times as long as the base of antennal segment VI. The apical rostral segment (RIV+V) is 1.1-1.33 times the length of the second hind tarsal segment. The dorsum of the abdomen has no pigmented sclerotic areas. The siphunculi are slightly swollen at the distal three-fifths, narrowing beyond the swelling to a prominent flange (cf. Macrosiphum euphorbiae, which have tapering siphunculi). The siphunculi are 2.5-3.2 times the caudal length. The cauda is rather hairy with 6-8 hairs on each side, and 3 or 4 dorsal ones.
Note: Robinson (1969) described the species under the name Aulacorthum capilanoense, which was later synonomised with Amphorophora forbesi. Based on various incompatible characteristics of this aphid with the Amphorophora genus, Jensen in Aphidtrek, and Blackman in Aphids on Worlds Plants have both expressed doubts about whether Richards assigned this species to the correct genus.
Image above copyright Andrew Jensen under a Creative Commons License.
The alate (not pictured) has 13-20 secondary rhinaria on antennal segment III, arranged in a straight line. The wings are hyaline except for a narrow fuscous border along each vein. There are no pigmented sclerotic areas on the dorsum of the alate.
Amphorophora forbesi feeds on the undersides of the leaves of salmonberry (Rubus spectabilis, see picture below).
Image above copyright Margalob under a Creative Commons License.
Jensen in Aphidtrek notes that it easily found on Rubus spectabilis, albeit it has yet to be found on any other Rubus species. Oviparae and males have not been described, but the species is most likely holocyclic monoecious. It has so far only been found in western North America, namely British Columbia in Canada and Washington & Oregon in the United States.
Other aphids on the same host
Amphorophora forbesi has been found on 1 species of Rubus (Rubus spectabilis).
Blackman & Eastop list 3 species of aphid as feeding on salmonberry (Rubus spectabilis) worldwide, and provide formal identification keys (Show World list). Of those aphid species, Baker (2015) lists 1 as occurring in Britain (Show British list).