Macrosiphoniella tanacetaria

Identification & Distribution:

Macrosiphoniella tanacetaria apterae (see first picture below) are large wax powdered green or pinkish-brown aphids. The antennae are black including the base of the third segment (cf. Macrosiphoniella artemisiae which has the base of antennal segment 3 brown). The legs, siphunculi and cauda are also black. There are no body hairs on dark scleroites. The antennae are 1.0-1.3 times the body length with the terminal process 2.9-3.5 times the length of the base of the last antennal segment. The siphunculi are 0.1-0.2 times the body length and 0.6-0.9 times the length of the cauda. The body length of apterae is 3.2-4.1 mm. The female alate (see second picture below) is much like the Macrosiphoniella tanacetaria aptera.

The picture below shows a Macrosiphoniella tanacetaria alate vivipara in alcohol.

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

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

The principal host plant of Macrosiphoniella tanacetaria is Tansy (Tanacetum vulgare), but the range of reserve hosts seems greater than in most Macrosiphoniella, including records from other Tanacetum species, species of Achillea, Anthemis, Artemisia, Aster, Bidens, Chamaemelum, Chrysanthemum, Dendranthema and Matricaria, and also Salvia officinalis (common sage). Colonies occur on upper parts of stem and between the flowers. Eggs are laid on the stem and withered leaves. Macrosiphoniella tanacetaria is common and widespread throughout Europe extending into North Africa, parts of Asia and the Americas.

Biology & Ecology:

There are two colour forms of Macrosiphoniella tanacetaria, green and pink. We have found the green form to be more common than the pink.

Masssonnet et al. (2002) looked at the pattern of dispersion of Macrosiphoniella tanacetaria on Tanacetum. A tansy plant (termed a genet) consists of many individual shoots (termed ramets). Macrosiphoniella tanacetaria was found to cluster at three spatial scales: at the level of ramets, at the level of genets and at the level of sites. At all these levels persistence is low - average survival time of aphid 'populations' on ramets is less than 2 weeks, on genets less than 4 weeks and probably only a few years in sites.

Stadler (2004) studied Metopeurum fuscoviride, Brachycaudus cardui, Aphis fabae and Macrosiphoniella tanacetaria. He found that numbers of the various species changed significantly depending on the quality of the host plant and the presence / absence of attending ants. The obligate myrmecophile, Metopeurum fuscoviride, was abundant on high-quality plants, while the unattended Macrosiphum tanacetaria did best in poor quality patches.

Loxdale et al. (2011) focused on the spatial and seasonal metapopulation structure and dynamics of Macrosiphoniella tanacetaria and Metopeurum fuscoviride. They showed that the two species rarely occurred together on the same plant at the same time, possible because of disturbance of Macrosiphoniella by the ants. Both species showed extreme genetic heterogeneity within a metapopulation structure. Indeed the number of genotypic clusters found for tansy aphids in an 80 square km area was similar to that found globally for the pest aphid Myzus persicae.

We have also found mixed species populations of Macrosiphoniella tanacetaria with other aphid species. The picture above shows an alate tansy aphid with a nymphs and (less obviously) an aptera and at least three Myzus ornatus. The latter species shows extremely good cryptic colouration against the green stem of tansy.

The honeydew produced by Macrosiphoniella tanacetaria tends to have little or no melezitose - a sugar specially attractive to ants (Fischer & Shingleton (2001)) - so it is not tended by ants. This results in an accumulation of honeydew around the large colonies of aphids which attracts large numbers of insects other than ants, especially vespids. The Vespula, first image above, is gleaning the honeydew from the leaves under the colony. The Vespula, second above, has been killed by a comb-footed spider (most likely Enoplognatha ovata).

Other aphids on same host:

Blackman & Eastop list 23 species of aphid as feeding on Tanacetum vulgare worldwide, and provide formal identification keys.

Of those aphid species, Baker (2015) lists 17 as occurring in Britain: Aphis fabae, Aphis gossypii, Aphis spiraecola, Aphis vandergooti, Aulacorthum solani, Brachycaudus cardui, Brachycaudus helichrysi, Coloradoa tanacetina, Macrosiphoniella abrotani, Macrosiphoniella millefolii, Macrosiphoniella tanacetaria, Macrosiphoniella tapuskae, Macrosiphum euphorbiae, Metopeurum fuscoviride, Pleotrichophorus glandulosus, Trama troglodytes, and Uroleucon tanaceti.

Acknowledgements Our particular thanks to Graham Hall for correcting our identification of the comb-footed spider, shown above, and 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  Loxdale, H.D. et al. (2011). Stay at home aphids: comparative spatial and seasonal metapopulation structure and dynamics of two specialist tansy aphid species studied using microsatellite markers. Biological Journal of the Linnaean Society, 104, 838-865.Full text  Massonet, B. et al. (2002). Metapopulation structure of the specialized herbivore Macrosiphoniella tanacetaria (Homoptera, Aphididae) Molecular Ecology 11, 2511-2521. Abstract  Stadler, B. (2004). Wedged between bottom-up and top-down processes: aphids on tansy. Ecological Entomology 29, 106-116. Abstract  Starý, P. Aphid parasites: Hymenoptera, Aphididae) of the Mediterranean area. Springer

 

Identification requests Nigel Gilligan, 17 March 2014, Macrosiphoniella species maybe Having looked at the Macrosiphoniella species overview, I think it does have that essence, but nothing that looks good enough, or have the correct parameters. I am hesitant at the flower, but I think it is probably Tansy (which is a thug, and have been trying to get rid of it). I looked for images of said genus on the web, and found one very similar to mine on Bug Guide, but no species name given! My photos unfortunately do not have a single shot in great focus throughout, so you have to put the bits together. First shot only for the sake of the hairs around the rear end. The cauda has an interesting non-symmetrical shape. Seen 8/9/2012. Images copyright Nigel Gilligan, all rights reserved.       Bob, Influentialpoints: Looks like a fourth instar nymph of Macrosiphoniella tanacetaria The second picture on our tansy aphid page gives the pink form. Beware of Bug guide - it's mostly American species, which may look similar [to UK species] but are not the same.