Uroleucon aeneum

Identification & Distribution:

Uroleucon aeneum apterae are shiny metallic bronze-black. The third antennal segment has rhinaria extending over 0.37-0.52 of the length. The tibiae have a paler middle section, and the hind femur is dark on the distal 0.4-0.5. Uroleucon aeneum siphunculi have reticulation on the distal 0.15-0.20, and the cauda is wholly dark (compare to the yellow cauda of Uroleucon cirsii ). The body length of apterae is 3.0-4.3 mm.

Guest image copyright Alan Outen, all rights reserved

Uroleucon aeneum lives in sometimes very large colonies on the upper parts of stems of thistles, mainly Carduus and Cirsium spp. The dark-tailed thistle aphid does not host alternate but remains all year round on thistle. Oviparae and alate males appear in September. Uroleucon aeneum is found throughout Europe to Turkey, Armenia, Kazakhstan and Siberia, and has been introduced to Argentina and Chile.

Other aphids on same host:

• Aside from a few polyphygous aphids, Blackman & Eastop list 29 aphid species  as feeding on Carduus thistles worldwide, and provide formal identification keys. Of those aphid species, Baker (2015)  lists 13 as occurring in Britain: Aphis fabae,  Aphis gossypii,  Aphis solanella, Brachycaudus cardui,  Brachycaudus helichrysi,  Brachycaudus lateralis,  Capitophorus carduinus,  Capitophorus elaeagni,  Pemphigus bursarius,  Protrama radicis,  Trama troglodytes,  Uroleucon aeneum and Uroleucon cichorii. 

• Blackman & Eastop list more than 55 species of aphid  as feeding on Cirsium thistles (also Cnicus) worldwide, and provide formal identification keys. Of those aphid species, Baker (2015)  lists at least 27 as occurring in Britain: Acyrthosiphon malvae,  Aphis craccivora,  Aphis fabae group,  Aphis gossypii,  Aphis solanella, Aphis spiraecola, Aulacorthum solani,  Brachycaudus cardui,  Brachycaudus helichrysi,  Brachycaudus lateralis,  Capitophorus carduinus,  Capitophorus elaeagni,  Capitophorus gynoxanthus, Dysaphis lappae sspp. cirsii,  Hyperomyzus lactucae,  Macrosiphum euphorbiae,  Myzus ascalonicus,  Myzus cymbalariae, Myzus persicae,  Nasonovia ribisnigri,  Protrama radicis,  Trama troglodytes,  Uroleucon aeneum, Uroleucon cirsii,  Uroleucon erigeronense and Uroleucon jaceae. 

Acknowledgements Our thanks to Alan Outen of the Bedfordshire Invertebrate Group  for his photo of a colony of Uroleucon aeneum. 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).

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