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Macrosiphoniella subterranea

Masked oxeye aphid

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

Identification & Distribution

Adult apterae of Macrosiphoniella subterranea (see first picture below) are reddish brown with a rather thick coating of greyish wax except for clearly defined patches on the mid-dorsum and around the bases of the siphunculi. The third antennal segment is mostly pale, and has 10-22 secondary rhinaria. The legs and antennae of Macrosiphoniella subterranea have contrasting pale and black sections. The siphunculi and cauda are black, and the siphunculi are 0.9 -1.15 times the length of the cauda.

Images copyright Graham Hall, all rights reserved.

The alate Macrosiphoniella subterranea (see second picture above) appears to lack the wax-free patch on the mid-dorsum, but is wax free around the bases of the siphunculi.

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

Macrosiphoniella subterranea usually feeds on the undersides of the leaves of ox-eye daisy (Leucanthemum vulgare) and shasta daisy (Leucanthemum x superba). Sexual forms develop in October and November, and the aphid overwinters in the egg stage. It is rare in Britain, being previously only found in Cumbria and Hertfordshire, but is widely distributed in continental Europe and is also found in North America.

 

Biology & Ecology

We are yet to find this species in Britain, but in 2018 Graham Hall found the aphids shown on this page at the RSBP Ham Wall Nature Reserve in the Somerset Levels near Glastonbury. They were living on leaves of ox-eye plants growing in a 'wild flower mix' sown around the car park.

Oxeye daisy, Leucanthemum vulgare = Chrysanthemum leucanthemum. Illustration from Flora Batava by Kops et al. (1800). Public domain, Wikipedia. 

The black and white pattern on this aphid makes it unmistakable - and very conspicuous on the host plant, especially when they are on the upper side of the leaf, as they are in the photos above and below.

Image copyright Graham Hall, all rights reserved.

The bold black and white coloration is almost certainly aposematic (=warning) coloration to dissuade birds and other vertebrate predators from attacking it. But whether this aphid is toxic or even distasteful to birds is not known. There are some reports that Leucanthemum is toxic to dogs and cats because of the presence of sesquiterpenes and pyrethrins (see shasta daisy ), but we can find no hard evidence for this. It is nevertheless likely that this aphid is distasteful as a result of the rather thick coating of white wax, and is utilising a common black-and-white pattern used by other distasteful insects (Mullerian mimicry).

Support for this comes from the observation that only a few mainly well-marked adults are to be found on the upper leaf surface (see picture above), whilst most of the aphid colony, including the more cryptically coloured immatures, remains out of sight on the underside of the leaf (see picture below). The adults on the leaf surface could be regarded as 'sacrificial lambs', possibly post-reproductive females which may get eaten, thus reinforcing a predator's aversion to black-and-white patterned aphids (see also Uroleucon tanaceti ). This is all the more credible when one remembers that most aphid colonies are clones - so the survival of the colony promotes every individual's genes.

Image copyright Graham Hall, all rights reserved.

An alternative hypothesis is that Macrosiphoniella subterranea is a Batesian mimic, where the aphid is quite innocuous, but is simply copying the colour pattern of an inedible black and white aphid such as Macrosiphoniella absinthii. 

Image copyright Graham Hall, all rights reserved.

One may wonder why the aphid was given the specific name subterranea when it clearly does not live underground (there are many species of aphids that feed on the stem collar or roots of plants - but this is not one of them). The reason appears to be that 'subterranea' in Latin also means hidden or masked. In other words the name refers to the resemblance of the dorsal wax cover to a mask.

 

Other species on the same host

Acknowledgements

We especially thank Graham Hall  for permission to use his photographs.

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).

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