Identification & Distribution:
Uroleucon sonchi is a large smooth dark brownish or pinkish-brown aphid with a glossy shine. Dorsal scleroites on abdominal tergites 1-5 are either absent, or very small (cf. Uroleucon cichorii, which has dorsal hairs arising from dark scleroites). Antesiphuncular sclerites are usually rudimentary or absent. The siphunculi are less than twice as long as the cauda. The coxae of Uroleucon sonchi are dark.
The clarified slide mounts below are of adult viviparous female Uroleucon sonchi : wingless, and winged.
Micrographs of clarified mounts by permission of Roger Blackman, copyright AWP all rights reserved.
The large sowthistle aphid lives on sowthistle (Sonchus species) especially common sowthistle (Sonchus oleraceus) and prickly sowthistle (Sonchus asper). It has a very wide distribution being found over most of the world.
Other aphids on same host:
- Blackman & Eastop list 36 species of aphid as feeding on common sowthistle (Sonchus oleraceus) worldwide, and provide formal identification keys.
Of those aphid species, Baker (2015) lists 24 as occurring in Britain:
- Blackman & Eastop list 23 species of aphid as feeding on field sow thistle (Sonchus arvensis) worldwide, and provide formal identification keys.
Of those aphid species, Baker (2015) lists 18 as occurring in Britain:
Our particular thanks to Roger Blackman for images of his clarified slide mounts.
Whilst we make every effort to ensure that identifications are correct, we cannot absolutely warranty their accuracy. We have mostly made 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).