Uroleucon campanulae

Identification & Distribution:

In life the adult aptera of Uroleucon campanulae (see first picture below) is shiny reddish brown to black. The fused apical rostral segments (RIV+V) are 0.8-1.05 times the length of the second hind tarsal segment (HTII). Their body hairs are thick and placed upon well developed scleroites. The legs are bicoloured yellow and black, and the antennae, siphunculi, and cauda are black. Uroleucon campanulae siphunculi have polygonal reticulation over more than 0.2 of their length. The siphunculi are 0.85-1.25 times the length of the cauda. The body length of Uroleucon campanulae is 2.1 to 3.7 mm.

Antesiphuncular sclerites are little developed in apterae, but usually well developed in alates (see second picture above). The images below are micrographs of Uroleucon campanulae in alcohol from Campanula rotundifoli in Dundreggan, Scotland.

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

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

The Harebell aphid feeds on the upper parts of stems and flowers of Campanulaceae (Harebells) especially Campanula rotundifolia, Campanula rapunculus and Jasione montana. Populations from different regions and hosts differ somewhat in morphology and there is possibly a complex of species in Europe. Uroleucon campanulae is found in Europe and Central Asia.

Biology & Ecology:

Uroleucon campanulae does not seem to be a common aphid and it has been little studied.

We have only found it once - in July at Dundreggan in northern Scotland.

Harebells (Campanula rotundifolia) were common, but Uroleucon campanulae was only found in one restricted location on about ten plants - just adjacent to a little used road.

Uroleucon campanulae spends its entire life cycle on bellflowers and does not host alternate. Sexual forms develop in autumn and the aphid overwinters in the egg stage.

Osiadacz & Halaj (2011) have looked at the diversity of aphid species on Campanulaceae (bellflowers). They noted that bellflowers have been colonized by only a limited number of aphids. Worldwide only a dozen or so aphid species are specifically associated with this family, whereas in Poland alone there are some 150 species associated with Asteraceae. Yet the Campanulaceae have about 2000 species worldwide. With the Asteraceae it seems there was coevolution of the aphid and plant species, but this has not happened with Campanulaceae. The plant family appears to have no notable defences and the sap is not toxic.

The low diversity seems to be because the vast majority of the Campanulaceae grow in very dry habitats, mainly xerothermic grasslands. Such habitats are 'challenging' for soft-bodied insects such as aphids. Also the degree of coverage by the plants is low - they grow separately rather than in dense aggregations.

Other aphids on same host:

Uroleucon campanulae has been recorded from 14 Campanula species.

• Blackman & Eastop list 7 species of aphid as feeding on harebell (Campanula rotundifolia) worldwide, and provide formal identification keys.

  Of those aphid species, Baker (2015) lists 5 as occurring in Britain: Dysaphis brevirostris, Dysaphis sorbi, Myzus ascalonicus, Rhopalosiphoninus staphyleae and Uroleucon campanulae.

Damage and control

Uroleucon campanulae is mentioned as a minor pest of decorative Campanula in Poland by Wilkaniec et al. (2008).

Acknowledgements Our particular thanks to Roger Blackman for images of his clarified slide mounts. Whilst we make every effort to ensure that identifications are correct, we cannot absolutely warranty their accuracy. We have mostly made 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

References Wilkaniec, B. et al. (2008). Aphid infestation of decorative perennials. Acta Sci Pol., Hortiorum Cultus 7(1), 13-19. Abstract Osiadacz, B. & Halaj, R. (2011). The aphids (Hemiptera: Aphididae) on Campanulaceae in Poland. Polish Journal of Entomology 80, 191-202.  Full text

 

Identification requests Nigel Gilligan, 14 March 2014, a dark red aphid with black spots I have struggled with this one, and think it might be one of the Uroleucon. It has all black siphunculi and cauda, black legs but orange bases to front & mid femora, and black antennae, which at least seems to fit Uroleucon campanulae. I can also see that it has very fine striations across the abdomen, almost like a fine mesh. As far as harebells are concerned, we did have some in the lawn, and there are a few patches round about. Seen 26/8/2012. One rubbish photo to show the overall shape from the rear, and the other 2 are detailed. Images copyright Nigel Gilligan, all rights reserved.     Bob, Influentialpoints: Your reddish aphid is indeed Uroleucon campanulae. It can look quite dramatic when you get a large colony on a harebell flower. Thanks very much for the Harebell aphid confirmation. That is good.