Macrosiphoniella asteris

Identification & Distribution

Adult apterae of Macrosiphoniella asteris are reddish brown suffused with green with a bronze sheen and sometimes a little wax powdering (see pictures below - although these may be oviparae). Dorsal hairs and their black scleroites are sparse and mainly arranged in longitudinal rows. The apical segment of the rostrum (RIV+V) is rather short, only 0.7-0.8 times the length of the second hind tarsal segment; it is not stiletto shaped as in other Macrosiphoniella, but has slightly convex margins. The antesiphuncular sclerites are rather large. The black siphunculi are 1.0-1.2 times the length of the cauda, which is dusky and paler than the siphunculi. The body length of adult Macrosiphoniella asteris apterae is 2.3-3.1 mm.

The alate vivipara has well developed marginal sclerites, and the spinal scleroites are fused in to cross bands on some tergites. The ovipara is similar to the viviparous female, and the apterous male is small and dark. The micrographs below show an adult Macrosiphoniella asteris aptera in alcohol, dorsal & ventral view (there is some foreshortening in the first image).

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

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

Macrosiphoniella asteris lives only on sea aster (Aster tripolium), feeding on the upper parts of the stems and the flowers. The species is found in coastal areas over most of Europe.

Biology & Ecology

Less is known about the ecology of the bronze sea aster aphid than is the case for some other salt marsh specialists. Healy (1975) investigated the salt marsh fauna of North Bull Island, in Ireland, during 1961-1963.

Sea aster (Tripolium pannonicum) (see picture above) hosted two salt marsh specialists: Aphis tripolii and Macrosiphoniella asteris. Colonies of Macrosiphoniella asteris were found on the sea aster in the marsh from July to September.

We have looked for this species in various salt marsh sites in Hampshire, Sussex and Kent, but have only found it once, very late in the year in October, in Keyhaven saltmarsh in Hampshire. Being so late in the year, there were sexuales present. The image below shows the small dark male of Macrosiphoniella asteris.

There were also a few immatures present (see picture below).

Other aphids on same host:

Macrosiphoniella asteris has not been recorded on any Aster species, and has only been recorded on 1 Tripolium species (Tripolium pannonicum).

Blackman & Eastop list 6 species of aphid as feeding on sea aster (Tripolium pannonicum) worldwide, and provide formal identification keys for aphids on Aster species.

Of those aphid species, Baker (2015) lists all 6 as occurring in Britain: Aphis fabae, Aphis tripolii, Brachycaudus helichrysi, Macrosiphoniella asteris, Myzus persicae and Pemphigus trehernei.

Acknowledgements 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 Healy, B. (1975). Fauna of the salt-marsh, North Bull Island, Dublin.. Proceedings of the Royal Irish Academy 75 B, 225-244. Full text