Panaphis
Kirkaldy, 1904
Species Guides
1- Panaphis juglandis(Walnut Aphid)
Panaphis is a of aphids in the Aphididae, Calaphidinae. The best-known , Panaphis juglandis, is a destructive pest of walnut trees (Juglans spp.) and forms mutualistic associations with tending ants. Ants protect these aphids from such as lady beetles in exchange for honeydew. The genus has been documented in parts of Europe including Denmark, Norway, and Sweden.
Pronunciation
How to pronounce Panaphis: /ˈpænəfɪs/
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Identification
Members of Panaphis can be distinguished from the related walnut aphid Chromaphis by differences in defense : Panaphis juglandis is less effectively controlled by the lady beetle Harmonia axyridis compared to Chromaphis juglandicola, with lower rates and reduced searching by this predator. Specific morphological diagnostic features for the genus are not detailed in available sources.
Images
Habitat
Walnut orchards and natural stands of walnut trees (Juglans spp.), specifically on common walnut (Juglans regia).
Distribution
Recorded from Denmark, Norway, and Sweden; specific distributions within the are not separately detailed.
Diet
Phloem sap feeder on walnut (Juglans spp.), specifically documented on Juglans regia.
Host Associations
- Juglans regia - plantcommon walnut
- Juglans - plantwalnut
Behavior
Forms mutualistic associations with tending . Ants exhibit variable defensive when aphids are attacked by lady beetles: some ant species fight and attempt to rescue grabbed aphids (observed in Crematogaster scutellaris), while others are less effective or flee.
Ecological Role
Destructive pest of walnut trees; serves as honeydew producer in - mutualisms; prey for predatory lady beetles including native Adalia bipunctata and Harmonia axyridis.
Human Relevance
Economic pest in walnut orchards; target of efforts using predatory lady beetles, though efficacy is complicated by mutualisms that protect aphids from .
Similar Taxa
- ChromaphisBoth are walnut-feeding ; Chromaphis juglandicola co-occurs with Panaphis juglandis on walnut and is more effectively controlled by Harmonia axyridis due to differences in protection or vulnerability.
More Details
Ant mutualism variability
The effectiveness of protection for Panaphis juglandis varies significantly by ant . Dolichoderus quadripunctatus and Lasius emarginatus are aggressive defenders, while Camponotus piceus is less effective and often flees from .
Predator interference effects
rates on Panaphis juglandis by Harmonia axyridis decrease with increasing due to interference between individual lady beetles.
Sources and further reading
- BugGuide
- GBIF taxonomy match
- iNaturalist taxon
- NCBI Taxonomy
- Catalogue of Life
- POPULATION DYNAMICS AND SPATIAL DISTRIBUTION OF Panaphis juglandis (Goeze, 1778) (Hemiptera: Aphididae) ON COMMON WALNUT (Juglans regia L.)
- Effect of temperature on predation by Harmonia axyridis (Pall.) (Coleoptera: Coccinellidae) on the walnut aphids Chromaphis juglandicola Kalt. and Panaphis juglandis (Goeze)
- Fight and rescue or give up and flee? Behavioural responses of different ant species tending the mutualist walnut aphid Panaphis juglandis to native and exotic lady beetles – CORRIGENDUM
- Fight and rescue or give up and flee? Behavioural responses of different ant species tending the mutualist walnut aphid Panaphis juglandis to native and exotic lady beetles