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Capitophorus carduinus

Green thistle aphid

On this page: Identification & Distribution 

Identification & Distribution:

Wingless viviparae of Capitophorus carduinus are pale greenish white to yellowish green (see pictures below of the two colour forms), almost translucent, often with two indistinct darker green longitudinal stripes. The terminal process of the antenna is 4.6-6.3 times the length of the base of the last antennal segment.

Capitophorus carduinus have long capitate hairs on the head and posterior abdominal segments (clearly visible in the micrographs below). Their siphunculi are pale, slender and cylindrical, and are 2.4-3.5 times the length of the cauda. The siphunculi have no distal reticulation and are without dark apices. The body length of wingless viviparae is 1.6-2.2 mm.

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

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

Unlike many of the other Capitophorus aphids whose primary host is oleaster (hence sometimetimes known as oleaster aphids) the green thistle aphid does not host alternate. The green thistle aphid lives on the undersides of the lower leaves of thistles (Carduus and Cirsium spp.). Capitophorus carduinus is found in Europe and in various Asian countries.

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).

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