InfluentialPoints.com
Biology, images, analysis, design...
Aphids Find them How to ID AphidBlog
"It has long been an axiom of mine that the little things are infinitely the most important" (Sherlock Holmes)

 

 

Brachycaudus cardui

Plum - thistle aphid

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

Identification & Distribution:

Brachycaudus cardui apterae (see first picture below) are brownish-yellow, pale green or brown, with separate cross bars on thoracic segments, a large shining black spot situated dorsally on the abdomen and 2 or 3 black stripes at the tip. The Brachycaudus cardui rostrum is long and reaches the hind coxae. The longest hairs on abdominal tergite 8 are 85-110 μm long, and the longest hairs on the hind femur are 40-80 μm long. (cf. the short-haired Brachycaudus lateralis for which the longest hairs on abdominal tergite 8 are 20-61 μm long, and the longest hairs on the hind femur are 10-25 μm long. ) Their siphunculi are black, thick and cylindrical and 1.7-3.4 times the length of their cauda. The body length of apterae is 1.8-2.4 mm.

The alate Brachycaudus cardui (see second picture above) has a large black patch on the dorsal abdomen. Immatures (see first picture below) are greenish or reddish. The second picture below shows a dorso-lateral view of an aptera in alcohol.

The clarified slide mounts below are of adult viviparous female Brachycaudus cardui : wingless, and winged.

Micrographs of clarified mounts  by permission of Roger Blackman, copyright AWP  all rights reserved.

In continental Europe Brachycaudus cardui host alternates between various Prunus species, mainly cherry, plum and apricot, and various wild and cultivated daisies (Asteraceae) especially thistle (Carduus and Cirsium spp.) and borage (Boraginaceae). In Britain it seems to live all year round on Asteraceae. Infested leaves undergo severe curling. Dense colonies occur at the base of flower heads and on the leaves. A return migration to primary hosts occurs in autumn. The plum-thistle aphid is found throughout Britain and Europe as well as in Asia, north Africa and North America.

 

Other aphids on same host:

Primary hosts

Brachycaudus cardui has been recorded on at least 14 Prunus species, ans there are about 72 species of aphids which feed on plants in the genus Prunus worldwide.

Secondary hosts

Acknowledgements

Our particular thanks to Roger Blackman for images of his clarified slide mounts.

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 

 

Identification requests

Alan Outen, 03 June 2014, Re: Aphid hunting

Today in Shefford, Beds I found a species on Oxford Ragwort (Senecio squalidus) but which was clearly not Aphis jacobaeae. Using the on-line Blackman and Eastop key it suggests four options: S. squalidus Brachycaudus cardui, helichrysi, lateralis; Macrosiphum euphorbiae, and I came down to Brachycaudus cardui, which I hope is correct.

Image(s) copyright Alan Outen,  all rights reserved.

   

Bob, InfluentialPoints:

  • Almost certainly Brachycaudus cardui. Can't distinguish B. lateralis from B. cardui in photos. B. lateralis is basically a short haired version of B. cardui. But looking at Blackman, they may be one and the same species, so for photos I'll just stick to B. cardui!

I have now looked at the hairs on the Brachycaudus under the stereo-binoc and these are certainly right for B. cardui.