Aphis longirostris

Identification & Distribution:

Adult apterae of Aphis longirostris (see first picture below) are dark green to dull bluish green and are not wax powdered. The abdominal dorsum is entirely membranous, except sometimes for a faint dusky spinal band on tergite 8. The fused apical rostral segment (RIV+V) is 1.45-1.63 times the length of the second hind tarsal segment, markedly longer than is the case with Aphis plantaginis. The siphunculi are 0.94-1.64 times the length of the cauda, somewhat shorter than those of Aphis plantaginis. All the hairs on the legs are shorter than the least width of the hind tibiae, most very much so. The body length of the adult Aphis longirostris aptera is 1.0-1.8 mm.

Aphis longirostris alatae were previously unknown, but we have recently (in July 2016) photographed live alatae of Aphis longirostris at Keyhaven salt marshes in Hampshire (see second picture above). They are very dark green with prominent marginal tubercles.

The sea plantain aphid lives on the root collar and radical leaf bases of sea plantain (Plantago maritima) and buck's horn plantain (Plantago coronopus). They do not host alternate, but remain all year on plantain where they are tented over with sand particles by ants. In autumn they produce apterous males and oviparae. They are widely distributed in coastal counties in Britain, but little recorded. Aphis longirostris have been found in several countries in continental Europe, as well as in west Siberia and Central Asia.

Biology & Ecology:

Aphis longirostris is always attended by ants, and colonies of these aphids can be found by the characteristic tenting around the plant, as shown in the picture below.

On Plantago coronopus, Aphis longirostris are usually concentrated on the young central shoot of the plant (see picture below).

Plantago maritima provides a rather different environment for the aphids - the leaves are long, linear and fleshy.

Aphis longirostris live along the length of the leaves protected by the leaf curvature.

Until now the alate of Aphis longirostris has been unknown, although why so few have ever been found is unclear. We found alatae in several of the populations we sampled at Keyhaven Marshes in Hampshire (all of which lay within an area of just 1 square meter). Stroyan (1957) stressed the difficult conditions (high wind) when taking his sample which included only three apterae.

Other aphids on same host:

• Blackman & Eastop list 3 species of aphid as feeding on sea plantain (Plantago maritima) worldwide, and provide formal identification keys (Show World list). Of those aphid species, Baker (2015) lists all 3 as occurring in Britain (Show British list).

• Blackman & Eastop list 3 species of aphid as feeding on bucks horn plantain (Plantago coronopus) worldwide, and provide formal identification keys. (Show World list). Of those aphid species, Baker (2015) lists all 3 as occurring in Britain (Show British list).

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  Stroyan, H.L.G. (1957). Further additions to the British aphid fauna. Transactions of the Royal Entomological Society of London 109(2), 311-360. Abstract