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Brachycaudus linariae

Toadflax aphid

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

Identification & Distribution:

Adult apterae of Brachycaudus linariae are deep blackish shiny green. Immatures are a somewhat paler green. The last two fused rostral segments range in length from 0.135 to 0.160 mm. The body length of adult Brachycaudus linariae apterae is 1.4-1.9 mm.

There are medium to large flat marginal tubercles on the pronotum and on some or all of abdominal tergites 1-5.

The micrographs below show an aptera, dorsal and ventral, in alcohol.

Brachycaudus linariae alatae have 11-33 secondary rhinaria on the third antennal segment, 6-9 on the fourth segment and 0-2 on the fifth segment.

The clarified slide mounts below are of adult viviparous female Brachycaudus linariae : wingless strongly sclerotized form, and winged.

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

Toadflax aphids live on the basal parts of toadflax, especially yellow toadflax (Linaria vulgaris). Sexual morphs of the toadflax aphid have not yet been found in UK, but have been recorded in Slovakia. Brachycaudus linariae is found in parts of western and northern Europe and most of eastern Europe.


Other aphids on same host:

Blackman & Eastop list 3 species of aphid  as feeding on yellow toadflax (Linaria vulgaris) worldwide, and provide formal identification keys.

Of those aphid species, Baker (2015)  lists 2 as occurring in Britain: Brachycaudus linariae and Macrosiphum euphorbiae. 


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).

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