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)

Search this site



Macrosiphoniella millefolii

Yarrow aphid

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

Identification & Distribution:

Apterae of Macrosiphoniella millefolii are of moderate size, green and wax powdered except for a spinal stripe on the abdomen and presiphuncular spots. The antennae, siphunculi and cauda are black; the legs are mostly black except for the basal part of the front femur which is brown. The antennae are 1.0-1.2 times the body length with the terminal process 3.7-4.3 times the length of the basal part. Dark sclerites are present on the sides and just in front of the siphunculi. There are numerous long body hairs on the dorsum positioned on dark scleroites; some of these may be fused into larger sclerites.The siphunculi are 0.12-0.15 times the length of the body and 0.8-0.9 times the caudal length.

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

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

The yarrow aphid does not host alternate and feeds on yarrow (Achillea millefolium). It has a sexual stage in its life cycle. Macrosiphoniella millefolii is common and widespread in Europe and North America.


Biology & Ecology:

The first picture below shows a dense colony of Macrosiphoniella millefolii on the flower stem of a yarrow plant.

The aphids in the colony above are of mixed age from the smallest I/II instar nymphs to the larger IV instar nymphs. Those with wing buds are destined to become alates. The colour of Macrosiphoniella millefolii is thought to mimic of the colour of the flower structures which may provide some protection from some natural enemies such as birds (Hille Ris Lambers, 1938). Lozzia et al. (2013) looked at the pattern of dispersion of Macrosiphoniella millefolii on Achillea collina, a medicinal plant grown for commercial purposes. The coefficients of Taylor's power law indicated aggregated distributions.

It is not unusual to find other species mixed in with colony - for example the picture below shows a dense colony of Macrosiphoniella millefolii with a single light yellow-green Myzus ornatus in the middle.

Morlacchi et al. (2011) compared the development of the polyphagous aphid Myzus persicae, considered a generalist, and the oligophagous aphid Macrosiphoniella millefolii, considered a specialist, on yarrow (Achillea collina). The wingless viviparae of the two species differed in the immature developmental time and survival, and in adult fecundity and life span. At high temperatures, the intrinsic rate of increase as an overall indicator of performance tended to be higher for the generalist than for the specialist aphid species, while the opposite appeared to occur at low and medium temperatures.

Lozzia et al. (2013) also looked at the population dynamics and economic impact of Macrosiphoniella millefolii on Achillea collina. They found indications for an influence of the plant and a possibly limited effect of natural enemies on aphid infestations.


We have also found high levels of parasitism of Macrosiphoniella millefolii. The braconid above (probably Aphidius absinthii) was found attacking Macrosiphoniella millefolii in Dundreggan, Scotland. Starý & Havelka (2008) recorded two Aphidiid species in the Czech Republic parasitizing Macrosiphoniella millefolii, Aphidius absinthii and Ephedrus niger.

Coccinellid larvae also predate Microsiphoniella species. The picture above shows a larva of Coccinella 14-punctata that had been recently feeding on a colony of Macrosiphoniella millefolii on Achillea millefolium.


Other aphids on same host:

Macrosiphoniella millefolii has been recorded from 16 Achillea species.

Blackman & Eastop list 46 species of aphid as feeding on yarrow (Achillea millefolium) worldwide, and provide formal identification keys (Show World list). Of those aphid species, Baker (2015) lists 26 as occurring in Britain (Show British list).


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


  • Blackman, R.L. & Eastop, V. (2006). Aphids on the World's Herbaceous Plants and Shrubs. Vols 1 & 2. J. Wiley & Sons, Chichester, UK. Full text

  • Hille Ris Lambers D. (1938). Contributions to a monograph of the Aphididae of Europe. I. The genus Macrosiphoniella Del Guercio, 1911. Temminckia, 3, 1-44.

  • Lozzia, G.C. et al. (2013). Comments on the dynamics of insect population assemblages and sampling plans for aphids in commercial alpine yarrow fields. Bulletin of Insectology 66(1): 35-43. Full text

  • Morlacchi, P. et al. (2011). The performance of Macrosiphoniella millefolii and Myzus persicae on Achillea collina. Bulletin of Insectology 64(1), 135-143.Full text

  • Rakhshani, E. et al. (2011). Aphidiinae parasitoids (Hymenoptera: Braconidae) of Macrosiphoniella aphids (Hemiptera: Aphididae) in the western Palaearctic region. Journal of Natural History 45, 41-42 DOI: 10.1080/00222933.2011.597004. Abstract

  • Starý, P. (1976). Aphid parasites (Hymenoptera, Aphidiidae) of the Mediterranean area. Dr W. Junk, The Hague.

  • Starý, P. & Havelka, J. (2008). Fauna and associations of aphid parasitoids in an up-dated farmland area (Czech Republic). Bulletin of Insectology 61(2), 251-276. Full text


Identification requests

Alan Watson Featherstone 7/8/2014

I was out at Dundreggan for a meeting on Tuesday this week and spotted some aphids on yarrow there, very close to where you found them last year. Please see the images [below] - I assume these are Macrosiphoniella millefolii.

Images copyright Alan Watson Featherstone/Trees for Life all rights reserved.


Bob, Influentialpoints:

  • Nice images!

    Yes, those rather photogenic beasties are indeed Macrosiphoniella millefolii.