A 'NEW' APHID IS CAUSING SEVERE DAMAGE TO LUPINS IN EAST ANGLIA G. D. HEATHCOTE
Essig's lupin aphid, Macrosiphum albifrons Essig, is a most unwelcom recent newcomer to East Anglia and other parts of England. This very large, blue-green aphid originated in North America and wasfirstfound in Britain in 1981 at the Royal Botanic Gardens, Kew (Stroyan, 1981). It was on lupins (Lupinus spp.) on which it completes its life cycle. It is not known to attack any other genera of Leguminosae or other plants. The lupins at Kew had all been grown from seed and the origin of the infestation is not known. It is at least possible that the infestation was started by a winged aphid which came as a stowaway on an aircraft landing at Heathrow. The chance of an aphid crossing the Atlantic in this way and of thenfindinga suitable host plant is, of course, extremely remote. However, even those aphids which attack only a limited number of plant species can sometimes be abundant locally and a few may then be carried by the wind or transported accidentally by man long distances from these sites. As most aphids are female, capable of producing twenty or more young without mating, and these young will in turn reproduce asexually, producing a similar number of young within about two weeks, it does not take long for a Single aphid to Start an infestation if conditions are favourable. The lupin aphid was caught for thefirsttime in the suction trap at Broom's Barn, Higham, Bury St Edmunds (run as part of Rothamsted's Insect Survey) in late June and early July 1983. In the same period Utamphoro phora humboldti (Essig), which is another aphid which is thought to hav come to England originally as a passenger on an aircraft, was trapped at Broom's Barn. They might conceivably have reached Europe overland from America by a series of long hops via Siberia and Central Europe, or by way of a very high air-mass (Dr C. S. Wood-Baker,pers. comm.). Whenfirstfound in Britain the lupin aphid was not thought to pose a serious threat, although it was considered prudent to keep a watch on gardens and nurseries for this pest, but in 1982 it had spread to many parts of London, and it had been found in Hertfordshire, Bedfordshire, Leicestershire and more generally in the South-east. In 1983 it was reported from Somerset, Dorset, the Isle of Wight, Anglesea, Yorkshire, many parts of Norfolk and Suffolk and in other counties. Several species of lupins are attacked, including the garden Russell lupin, L. polyphyllus Lindl., and the tree lupin, L. arboreus Sims. The aphi first discovered on L. albifrons Benth. in California in 1911. In Suffolk it ha been found on L. polyphyllus at Lowestoft, Southwold, Wenhaston, Bun gay, Haiesworth and Bury St Edmunds, and on L. arboreus at Lowesto Corton, Kessingland, Haiesworth, and from Southwold to Thorpness. In Norfolk it was reported on L. polyphyllus at Norwich, Felthorpe, Brundal Taverham, Stoke Holy Cross, Long Stratton, Pulham Market, Harleston, Bungay, Thetford, Downham Market, Fakenham, Lyng, Thursford, Trans. Suffolk Nat. Soc. 21