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Aulacorthum palustre

Wax-banded daisy aphid

On this page: Identification & Distribution  Biology & Ecology  Other aphids on the same host 

Identification & Distribution

Adult apterae of Aulacorthum palustre are whitish green, pale green or pinkish with black tips to the antennae and legs. The dorsum and antennae have short capitate hairs. They often have rust-coloured or darker green spots around the bases of the siphunculi. The siphunculi are straight and pale, 1.8-2.5 times the length of the cauda, often with conspicuous darkened flanges. Immature Aulacorthum palustre have serial cross bands of whitish wax powder around the body (see pictures below of fourth instar nymphs), but these are apparently lost by the adult stage.

The alate Aulacorthum palustre is reddish or greenish with a brown or black abdominal dorsal pattern. The siphunculi are brown or with brown apices.

Aulacorthum palustre feed on the underside of leaves of plants in the daisy family (Asteraceae) such as cats ear (Hypochaeris), oxtongues (Picris), and possibly dandelions (Taraxacum) and hawkbits (Leontodon). They do not host alternate but live all year round on the same host. They may produce sexuales in autumn and overwinter as eggs, or they may overwinter parthenogenetically as viviparae. Aulacorthum palustre is found throughout Britain and much of Europe.

 

Biology & Ecology

Aulacorthum palustre seems to be rather a rare aphid in Britain, and we have only found it once. Heie (2009)  uses Aulacorthum palustre as an example of an aphid that, in Denmark at any rate, is rare having only been found once, despite its food plant being common. Heie observed that of 481 known species in Denmark, 93 had only ever been found once in that country (about 20%). We suggest in Rare aphids and conservation  that around half the aphids recorded in Britain can be regarded as rare. In the case of Aulacorthum palustre its apparent rarity may just result from it being under-recorded, given its cryptic habitat underneath the lower leaves.

 

Other aphids on same host:

Acknowledgements

Special thanks to Roger Blackman for identifying this aphid which we found wandering amongst numerous Aphis hypochoeridis on the root base of a cats ear plant (not its true feeding site), having dropped from the underside of one of the lower leaves.

We have made provisional identifications from high resolution photos of living specimens, along with host plant identity. In the great majority of cases, identifications have been confirmed by microscopic examination of preserved specimens. We have used the keys and species accounts of Blackman & Eastop (1994)  and Blackman & Eastop (2006)  supplemented with Blackman (1974) , Stroyan (1977) , Stroyan (1984) , Blackman & Eastop (1984) , Heie (1980-1995) , Dixon & Thieme (2007)  and Blackman (2010) . We fully acknowledge these authors as the source for the (summarized) taxonomic information we have presented. Any errors in identification or information are ours alone, and we would be very grateful for any corrections. For assistance on the terms used for aphid morphology we suggest the figure  provided by Blackman & Eastop (2006).

Useful weblinks 

References

  • Heie, O.E. (2009). Aphid mysteries not yet solved /Hemiptera:Aphidomorpha/ Monograph: Aphids and other hemipterous insects 15, 31-48. Full text