largely from four families - Mycetophilidae (the fungus gnats), Sciaridae, Platypezidae and
Heleomyzidae. Numerous other families have one or two or a few member species with fungus
feeding larvae.
The fungus Pleurotus cornucopiae is confined to elm and in Britain one fly species is
confined to this fungus - Brachypeza radiata (Mycetophilidae). The larvae are white with a
black head and can be found sometimes in numbers burrowing into the flesh of the fungus. I
have found this species in Dagnam Park, Romford usually around decaying elms. P. J. Chandler
(1973) gives an account of this fly and others he found associated with elm in Kent. Many other
fungi are found on elm but not specific to it and these host a wide range of Diptera from various
families.
Finally, it is worth noting here the flies of the genus Microsania (Platypezidae), tiny, black
insects that are almost only ever found in the smoke of bonfires. I came across a swarm of
Microsania pectinipennis near a smouldering elm in Dagnam Park in 1980. Nine males were
taken as they hovered in the midst of the smoke.
Very few flies have a specific association with elm, but an elm tree in the various stages of
its life will provide flies with a great range of micro-habitats as diverse as exudations, rot-holes,
leaves, flowers, bark decaying wood and associated fungi. For the diligent observer there still
remains much to be discovered about elms and their insect fauna.
References
(Note the nomenclature used in this chapter follows Kloet, G. S. and Hincks. W. D. (1975) A Check List
of British Insects. Hndbk Ident. Br. Ins. Vol. XI. pt. 5.)
d'Assis Fonseca, E. C. M. (1978) Handbk. Ident. Br. Ins. Vol. IX. pt. 5. Diptera: Dolichopodidae.
Barnes. H. F. (1951) Gall Midges of Economic Importance. Vol. 5. 129-35.
Benson, J. F. et al. (1974) Abundance of Odinia meijerei Collin (Diptera: Odiniidae) Ent. Mon. Mag. Vol
110.50.
Chandler, P. J. (1973) Some diptera and other insects associated with decaying elms (Ulmus procera
Salisbury) at Bromley, Kent, with some additional observations on these and related species. Ent. Gaz.
Vol. 24. 329-346.
Cogan, B. H. (1968) Two Species of the genus Odinia Robineau-Desvoidy (Diptera: Odiniidae) new to
Britain one of which is new to science. Ent. Mon. Mag. Vol. 104. 252-3.
Collin, J. E. (1952) On the European species of the genus Odinia Robineau-Desvoidy (Diptera: Odiniidae)
Proc. Roy. Ent. Soc. Lond. B. 21. 110-116.
Lewis, D. C. (1978) The Larvae and Purparium of Odinia meijerei Collin (Diptera: Odiniidae). Ent. Mon.
Mag. Vol. 114. 233-5.
Robinson, I. (1953) The Post-embryonic stages in the life-cycle of Aulacigaster leucopeza (Meigen)
(Diptera Cycolorrhapha: Aulacigasteridae). Proc. Roy. Ent. Soc. Lond. A. 28. 77-84.
Shillito, J. F. (1948) Notes on Insects Visiting Diseased Elms. Ent. Mon. Mag. Vol. 83. 290-2.
Stubbs, A. E. and Chandler, P. J. (Eds.) (1978) A Dipterist's Handbook. A.E.S.
Stubbs, A. E. and Falk, S. ]. (1983) British Hoverflies. B.E.N.H.S.
Uffen, R. W. J. (1962) Some Flies (Diptera) Breeding in Wounds on Elm Trees in Hyde Park. London
Naturalist. Vol. 42. 25.
5) Lichens and Fungi. Mr. J. F. Skinner
Lichens
The bark of elm is somewhat spongy in nature, allowing it to hold moisture quite well, rather
like that of oak and ash. This characteristic, together with a mildly acid to neutral chemistry,
produces a bark that can bear a rich and specialised flora of epiphytes. Watson et al. (1988)
record 200 species of lichens as occurring on elms, compared with 326 on oak (the highest total),
265 on ash, 160 on willows and 44 on hornbeam.
Forty-eight species of lichen have been recorded from elms in Essex since 1970, most of
them since 1980 by P. M. Earland-Bennett and myself. Most of the recent records are from logs
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