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Aphis taraxacicola

Dandelion aphid

On this page: Identification & Distribution  Biology & Ecology 

Identification & Distribution:

Aphis taraxacicola apterae are mottled dark green (see first picture below), and are not wax powdered. Their siphunculi are dark and the cauda is dusky. Aphis taraxacicola alates (second picture below) are also mottled dark green.

The apparent wax powdering of the dorsum of Aphis taraxacicola in the picture below is actually condensed water droplets following cooling to preserve the sample.

The terminal process of the sixth antennal segment is 2.1 to 2.8 times the length of the base of that segment. The abdominal sclerotic pattern varies from being heavily marked with dark intersegmental muscle sclerites and small marginal and postsiphuncular sclerites across tergites 7-8 to almost complete lack of any dark pigmentation. Abdominal marginal tubercles are rather large and prominent, and clearly visible in the micrographs below. The hairs on their legs are short with all femoral hairs shorter than the least width of the hind tibiae. Aphis taraxacicola siphunculi are 1.2 to 2.4 times the length of the cauda. The body length is 1.6 to 2.02 mm.

Aphis taraxacicola is closely related to Aphis hypochoeridis  and Aphis crepidis both of which share an association with yellow-flowered Asteraceae.

The dandelion aphid is found on the root collar and under the rosette leaves of Taraxacum (dandelion) species, mostly in dry sunny places with low or sparse vegetation. Aphis taraxacicola is usually ant attended and the ants tent over the colony with soil particles. It does not host alternate and sexual forms are found in autumn. It is found throughout Britain and the rest of Europe and in Siberia, with additional records from Canada and Japan (Sugimoto & Takahashi, 1996 ).

 

Biology & Ecology:

We first came across the dandelion root aphid when walking along the road past a local churchyard. A dandelion (Taraxacum officinale) was (just) managing to grow between the wall and the tarmac, and had a powdering of soil over its basal rosette of leaves (see first picture below). Careful brushing away of the soil revealed a colony of mottled dark green aphids shown below. The aphids had been tented over with soil particles by common black garden ants Lasius niger (see second picture below), rendering the aphids themselves invisible to any casual observer.

 

Aphis taraxacicola is one of 14 aphid species recorded in the nests of Lasius flavus in Poland by Depa. & Wegierek (2011)  It was found in a Lolio-Polygonetum meadow, situated in a housing estate, and described as intensively trodden on and regularly mown with a relatively low plant species diversity.

Despite this concealment and the attending ants, predators and parasitoids were still operating under the soil particle tent. We found parasitoids (below left, as yet unidentified) busy going round the colony parasitizing the aphids, and we found parasitized 'mummies' (below right). The straw-coloured aphid in the middle of this colony (second image on this page) was an aphid in process of mummification.

 

The parasitoid Lysiphlebus fabarum has been recorded attacking Aphis taraxacicola in Iran (Barahoei et al., 2014  ) and Serbia (Zikic et al., 2012 ).

As for predators, attending ants can certainly reduce the number of predators, but we have still found syrphid larvae amongst Aphis taraxacicola colonies (see below).

Coccinellid larvae of the genus Scymnus are reputedly important predators of root aphids, but we have so far only found them predating conifer aphids and the pellitory-on-the-wall aphid (Aphis parietariae ).

Acknowledgements

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 

References

  •  Barahoei, H. et al. (2014). Checklist of Aphidiinae parasitoids (Hymenoptera: Braconidae) and their host associations in Iran. Journal of Crop Protection 3(2), 199-232. Full text 

  •  Depa, L. & Wegierek, P. (2011). Aphid fauna (Sternorrhyncha, Aphidinea) in the nests of Lasius flavus (Fabricius, 1781) (Hymenoptera, Formicidae) of various plant communities. Aphids and other hemipterous insects 17, 73-79. Full text 

  •  Sugimoto, S. & Takahashi, S. (1996). New record of Aphis taraxacicola (Borner) (Homoptera: Aphididae) from Japan. Japanese Journal of Entomology 64(2), 288. Abstract 

  •  Zikic, V. et al. (2012). Aphidiinae (Hymenoptera: Braconidae) of Serbia and Montenegro - tritrophic interactions. Acta Entomologica Serbica 17 (1/2), 83-105. Abstract