Amphorophora

Buckton, 1876

Berry Aphids

Species Guides

Amphorophora agathonica(American Large Raspberry Aphid)
Amphorophora ampullata(Dark-tipped Fern Aphid)

Amphorophora is a of aphids in the Aphididae, established by George Bowdler Buckton in 1876. The genus contains approximately 27 , predominantly distributed in the Nearctic region with presence in Eurasia and North America. Species within this genus are significant agricultural pests of Rubus crops, particularly raspberries and blackberries. Several species, including A. idaei and A. agathonica, are major of plant viruses affecting commercial berry production.

Amphorophora agathonica by (c) Barry Cottam, some rights reserved (CC BY), uploaded by Barry Cottam. Used under a CC-BY license.

Amphorophora janesi by the Smithsonian. Used under a CC0 license.

Amphorophora rubicumberlandi by the Smithsonian. Used under a CC0 license.

Pronunciation

How to pronounce Amphorophora: //æmˌfɔːrəˈfɔːrə//

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Identification

Amphorophora can be distinguished from other by morphological features measurable on virginoparae. A. idaei (raspberry-feeding) and A. rubi (blackberry-feeding) can be separated using simple biometric methods based on pairs of morphological variables; A. idaei has a complement of 2n(♀)=18, while A. rubi has 2n(♀)=20. Canonical variates analysis based on eight characters reliably separates these two species.

Images

Habitat

Primarily associated with Rubus . A. idaei develops on European raspberry (Rubus idaeus), with nymphs developing on primocane tips and migrating to floricanes during bloom. A. rubi occurs on blackberry and brambles (R. fruticosus agg.). A. agathonica has been studied on 'Latham' red raspberry in Wisconsin. Some species utilize secondary for part of the , though these remain unidentified for A. agathonica.

Distribution

distributed across Eurasia and North America. -level distribution: A. idaei occurs in Europe; A. rubi in Europe and North America; A. agathonica documented in Wisconsin, USA. GBIF records indicate presence in Denmark, Norway, and Sweden. Most species are Nearctic in distribution.

Seasonality

A. agathonica in Wisconsin shows hatching in early May; peak late June to early July, declining through August; alatae appear mid-June; sexual forms and eggs produced in October. A. idaei and A. rubi show reduced resistance expression in autumn on some cultivars.

Diet

Phloem sap feeder. A. idaei feeds on raspberry plant phloem tissue. A. agathonica feeds on phloem sap of red raspberry (Rubus idaeus), utilizing primocanes and floricanes.

Host Associations

Rubus idaeus (European raspberry) - primary A. idaei; major pest and virus
Rubus idaeus 'Latham' (red raspberry) - primary A. agathonica
Rubus fruticosus agg. (blackberry, brambles) - primary A. rubi
Secondary hosts (unidentified) - summer A. agathonica; late summer destination

Life Cycle

Holocyclic with sexual phase. A. agathonica: overwinters as on raspberry canes; eggs hatch early May; nymphal development on primocane tips; to floricanes during bloom; return to primocanes; alatae production mid-June for migration to secondary ; return to raspberry for and egg-laying in October. Parthenogenetic dominates spring-summer; sexual reproduction occurs in autumn.

Behavior

A. idaei shows delayed probing initiation and prolonged time to reach phloem on raspberry cultivars compared to susceptible ones; altered phloem salivation patterns on resistant cultivars. A. agathonica exhibits seasonal between primocanes and floricanes. Alatae settle preferentially on upper zones of non-resistant raspberry cultivars; reduced settling on resistant cultivars containing major resistance genes A1 and A10.

Ecological Role

Major agricultural pest of cultivated raspberries and blackberries. A. idaei Raspberry leaf mottle virus (RLMV), Raspberry leaf spot virus (RLSV), Black raspberry virus (BRNV), and Rubus yellow net virus (RYNV). Despite heavy , A. agathonica showed no significant yield reduction on 'Latham' raspberry in Wisconsin study.

Human Relevance

Significant economic impact as pest of commercial berry production. Multiple strains of A. rubi (European raspberry strains 1, 2, and 3) and A. idaei strains have been identified, complicating resistance breeding programs. Raspberry breeding programs have developed cultivars with resistance genes (A1, A10, minor genes) that reduce settling, feeding, and . A rapid 48-hour screening test using floating leaflets has been developed to assess cultivar resistance.

Similar Taxa

Other Macrosiphini aphidsMorphological similarity; Amphorophora distinguished by specific biometric characters and numbers
Aphis rubicolaBoth occur on Rubus; Amphorophora are larger and have different morphological proportions

More Details

Chromosomal differentiation

Karyotype differences underpin separation: A. idaei has 2n(♀)=18, A. rubi has 2n(♀)=20.

Resistance gene effectiveness

Gene A1-containing cultivars bred in England showed much higher resistance to strain 1 A. idaei than those bred in Scotland, suggesting geographic variation in strain or screening methodology effects.

Virus vector capacity

Feeding differences between and susceptible cultivars are insufficient to explain virus resistance, indicating that resistance mechanisms may act through other .