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Aphidinae : Uroleucon upatorifoliae
 

 

Uroleucon eupatorifoliae

Varicolored snakeroot aphid

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

Identification & Distribution

Adult apterae of Uroleucon eupatorifoliae are dark dull green and/or red-brown (see note below). The head has large diverging antennal tubercles which bear several rather long, hyaline hairs. Their antennae are longer than the body. The first two antennal segments are greenish-brown, the remaining segments are very dark brown or black. Many of hairs on antennal segment III are longer than the basal diameter of that segment. Marginal tubercles on the abdomen are usually absent, and brown scleroites are usually present around dorsal abdominal setae. The legs have the femoral bases pale greenish, and the apical portion dark brown; the tibiae are dark brown. The siphunculi are dark brown to black, widest at the base, and tapering slightly toward the apex. The apical one-third is reticulated, with the portion below the reticulations heavily imbricated. The cauda is dark, long and narrow with a definite constriction below the middle (cf. Uroleucon nigrotuberculatum, Uroleucon eupatoricolens and Uroleucon ambrosiae, all of which have a mostly pale cauda). The cauda bears four long slightly curved hairs on each side, and two or three shorter dorsal ones.

Note: The only first-hand description we can find of live Uroleucon eupatorifoliae in the literature is Tissot (1935) who describes the aptera as being dull, dark green mottled with lighter areas, and the alate as having the anterior third and lateral margins of the abdomen a very dark dull green, but the middle portion reddish-brown. Both the apterae and alatae photographed here were mainly dark reddish-brown with dark-greenish head and thorax. Blackman in Aphids on Worlds Plants suggests that Uroleucon eupatorifoliae is synonomous with Siphonophora (= Macrosiphum) eupatorii) described from Nebraska, a species which Williams (1911) described as being greenish- or reddish-brown and living on Eupatorium ageratoides (= Ageratina altissima) & Eupatorium perfoliatum.

Both images above by permission, copyright Claude Pilon, all rights reserved.

The alate of the reddish-brown form is shown above. The antennae are slightly longer than the body, with the segments I-II very dark brown, and remaining segments black. Antennal segment III has approximately 30 secondary rhinaria scattered over more than half the surface of the segment.

Both images above by permission, copyright Claude Pilon, all rights reserved.

The images below are from the Centre for Biodiversity Genomics, University of Geuelph, Ontario and show a live aptera and a preserved alate of Uroleucon eupatorifoliae.

First image above copyright (2010) Her Majesty the Queen in Right of Canada, Agriculture & Agri-Food Canada.
Second image above copyright CBG Photography Group under a Creative Commons license.

Uroleucon eupatorifoliae was first described from Eupatorium incarnatum (= Fleischmannia incarnata) in Florida. It has also been recorded from the same host in more northerly states in eastern USA and (these observations) from Eupatorium ageratoides (= Ageratina altissima) in Canada. Sexual morphs have been collected in December in Florida.

 

Other aphids on the same host

  • Uroleucon eupatorifoliae has been recorded from 1 species of Ageratina (Ageratina altissima).

    Blackman & Eastop list 5 species of aphid as feeding on white snakeroot (Ageratina altissima) worldwide, and provide formal identification keys (Show World list). Of those aphid species, Baker (2015) lists 2 as occurring in Britain (Show British list).

  • Uroleucon eupatorifoliae has been recorded from 1 species of Fleischmannia (Fleischmannia incarnata).

    Blackman & Eastop list 1 species of aphid as feeding on pink thoroughwort (Fleischmannia incarnata) worldwide, and provide formal identification keys (Show World list). Of those aphid species, Baker (2015) lists none as occurring in Britain (Show British list).

Acknowledgements

We are grateful to Claude Pilon for pictures of Uroleucon eupatorifoliae (for more of her excellent pictures see).

Identification of specimens photographed by Claude Pilon was confirmed by Eric Maw by microscopic examination and DNA analysis of preserved specimens. For taxonomic details we have used the accounts of Tissot (1934) and Williams (1911) together with information from Roger Blackman & Victor Eastop in Aphids on Worlds Plants. We fully acknowledge these authors and those listed in the reference sections 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

  • Tissot, A.N. (1934). Two new aphids of the tribe Macrosiphini. The Florida Entomologist 18(2), 17-23. Full text

  • Williams, T.A. (1911)[1910]. The Aphididae of Nebraska. University of Nebraska University Studies 10(2), 85-91 (p 77).