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Hawthorn - Angelica aphidOn this page: Identification & Distribution Biology & Ecology Other aphids on the same host
Identification & Distribution:On their primary host, hawthorn, Dysaphis angelicae fundatrices cannot be distinguished from others of the Dysaphis crataegi species group - please refer to Dysaphis crataegi (Hawthorn-carrot aphid) for pictures of the fundatrix and gall. On their secondary host Dysaphis angelicae adult apterae (see first picture below) are greyish green with some white wax powdering. They also have a little reddish suffusion around the around the siphunculi, but this is much more prominent in immatures. Their antennae are short - about 0.3 times the body length. Their siphunculi are also quite short at 0.083-0.12 times the body length, but their length is more than twice their basal width.
The Dysaphis angelicae alate (see second picture above) has the bands on its doral abdomen fused to form a solid black patch.
The hawthorn - angelica aphid host alternates between hawthorn (Crataegus spp.) as the primary host and angelica (Angelica sylvestris) as the secondary host. On the primary host Dysaphis angelicae induces a cherry-red leaf gall. All females of the second generation are winged and migrate. On the secondary host it forms colonies on the lower leaf bases. Dysaphis angelicae occurs throughout much of Europe.
Biology & Ecology:
Unlike most of the species using hawthorn as a primary host, Dysaphis angelicae is restricted to a single hostplant species, wild angelica (Angelica sylvestris) as its secondary host. Wild angelica has white or pinkish flowers in umbels, and can be distinguished from related species by its hairless, ridged purple stem and its inflated sheathing leaf petioles (see pictures below).
Dysaphis angelicae lives in quite large colonies on wild angelica between the sheathing leaf bases and the stem.
The colonies are usually attended by ants.
The picture above shows Myrmica ants in attendance of Dysaphis angelicae.
Colonies are also commonly attended by the common black garden ant (Lasius niger) (see first picture below). Depa & Wojciechowski, 2008 found Dysaphis angelicae living inside the nests of Lasius niger.
More rarely Formica ants are in attendance, as in the second picture above showing a southern wood ant (Formica rufa).
If ants are in attendance, there is seldom much evidence of predator activity.
However, in one unattended colony we found some aphids were parasitized by trombidiid mites (see first picture above), and a few predatory syrphid larvae were present (see second picture above).
Other aphids on same host:
Blackman & Eastop list 16 species of aphid as feeding on common hawthorn (Crataegus monogyna) worldwide, and provide formal identification keys.
Of those aphid species, Baker (2015) lists 15 as occurring in Britain: Aphis fabae, Aphis gossypii Aphis pomi, Aphis spiraecola, Aulacorthum solani, Dysaphis angelicae, Dysaphis apiifolia, Dysaphis crataegi, Dysaphis lauberti, Dysaphis ranunculi, Ovatus crataegarius, Rhopalosiphum oxyacanthae, Ovatus insitus, Prociphilus pini and Rhopalosiphum rufulum.