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Uroleucon jaceicola

Yellow-legged knapweed aphid

Identification & Distribution 

Identification & Distribution:

Apterae of Uroleucon jaceicola are dark bronze-brown. Body hairs are strong, pointed and placed on rather large scleroites. Their coxae are dark, but the legs are yellow apart from black knees and black apices to the tibiae (compare with Uroleucon jaceae  which has wholly dark tibiae).

Image of aptera: guest image copyright Nigel Gilligan, all rights reserved

Uroleucon jaceicola siphunculi are black, although they may be paler in summer than in spring. They are 2.0-3.0 times the length of the cauda. The cauda is pale and bears 9-18 hairs (cf. Uroleucon jaceae which has a black cauda). The body length of the aptera is 2.9-3.3 mm.

Uroleucon jaceicola lives on the stems of common knapweed (Centaurea nigra). In spring it is found mainly low on stem, but moves to the upper parts later on. Oviparae and very dark apterous males of Uroleucon jaceicola have been found on the petioles of radical leaves in October. Uroleucon jaceicola is found in Europe, west Siberia and Central Asia.

Acknowledgements

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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