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Aphidinae : Macrosiphini : Macrosiphoniella millefolii
 

 

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 antesiphuncular spots (cf. Macrosiphoniella usquertensis, which are brownish with a thick coating of greyish wax except for clearly defined patches on the mid-dorsum and around the bases of the siphunculi). Their antennae, siphunculi and cauda are black. The tibiae and femora are mostly black except for the basal part of the front femur which is brown (cf. Macrosiphoniella ptarmicae, whose tibiae a paler middle section). The antennae are 1.0-1.2 times as long as the body 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 which may be fused into larger sclerites (cf. Macrosiphoniella tanacetaria, which does not have dorsal abdominal hairs arising from dark scleroites). The siphunculi are 0.8-0.9 times the length of the cauda (cf. Macrosiphoniella sejuncta, which has siphunculi 1.7 to 2.2 times the length of the cauda, and Macrosiphoniella tapuskae, which has siphunculi 1.8-2.3 times the length of the cauda). The body length of adult Macrosiphoniella millefolii apterae is 2.1-3.6 mm.

Alatae and immatures are similarly pigmented to the apterae, although the alatae seem to have rather less wax. 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 mainly feeds on yarrow (Achillea millefolium), but it has been found on many other Achillea species, as well as on daisies (Leucanthemum), tansies (Tanacetum) and mayweeds (Tripleurospermum spp.). It does not host alternate, but does have a sexual stage in its life cycle. Macrosiphoniella millefolii is common and widespread in Europe into Asia and has been introduced into North America.

 

Biology & Ecology:

Life cycle

Overwintering eggs, laid on the stems of yarrow (Achillea millefolium) the previous autumn, hatch in spring to give fundatrices. These reproduce parthenogenetically giving birth to live young which mature and reproduce in turn. By mid-June there can be dense colonies of Macrosiphoniella millefolii living on the flower stems of their host plant (see picture below).

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.

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 alates are the dispersive phase of the species, and spread to other hosts at the right plant growth stage.

Populations can reach high levels in summer, although predation and parasitism (see natural enemies below) take a heavy toll.

From September onwards increasing number of sexuales develop. Male Macrosiphoniella millefolii are readily distinguished by their pinkish-red coloration.

Like most (but not all) Macrosiphoniella species, the males are winged.

The oviparae (see picture below) are coloured much as the viviparae.

After mating oviparae deposit their eggs on the yarrow stems.

Colour

The colour of Macrosiphoniella millefolii is thought to mimic the colour of the flower structures which may provide some protection from some natural enemies such as birds (Hille Ris Lambers, 1938).

Interspecific competition / association

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 relative 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 (rm) 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.

Natural enemies

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 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.

In southern England the most frequent predators we have found active in Macrosiphoniella millefolii colonies are syrphid larvae.

We have not identified the larva pictured first above, but the second appears to the larva of Syrphus ribesii, a common aphidophagous syrphid. Colonies later in the year are frequently littered with the remains of aphids which have been sucked dry by the marauding syrphid larvae.

Coccinellid larvae also predate Macrosiphoniella species. The picture below shows a larva of the fourteen-spot ladybird (Propylea quattuordecimpunctata) that had been recently feeding on a colony of Macrosiphoniella millefolii on Achillea millefolium.

Anthocorids are also occasional predator of Macrosiphoniella millefolii on yarrow.

 

Other aphids on same host:

The normal host of Macrosiphoniella millefolii is yarrow (Achillea millefolii) but it also occurs on 15 other Achillea species (Achillea ageratum, Achillea alpina, Achillea atrata, Achillea colina, Achillea crithmifolia, Achillea distans, Achillea erba-rotta, Achillea filipendula, Achillea ligusta, Achillea nabelki, Achillea nobilis, Achillea ptarmica, Achillea ptarmicifolia, Achillea tomentosa, Achillea umbellata).

Macrosiphoniella millefolii feeds on one species of Leucanthemum (Leucanthemum vulgare).

Macrosiphoniella millefolii feeds on 3 species of Tanacetum (Tanacetum millefolium, Tanacetum parthenium, Tanacetum vulgare. ).

Macrosiphoniella millefolii feeds on 1 species of Tripleurospermum (Tripleurospermum inodorum).

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

  • 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.