BR .1, I.N I NA I HIST. 13: 2001 



FUNGUS GNATS (DIPTERA: SCIAROIDEA) NEW TO BRITAIN 



Peter J. Chandi i r 

 43 Eastfield Road, Burnham, Slough, Berks SL1 7 EL 



Abstract: The British fauna of the families Ditomyiidae, Keroplatidae and 

 Mycetophilidac is updated and changes introduced in the checklist explained. Six 

 species of Mycctophilidae are newly described: Clastobasis loici, Sciophila caesarea, 

 Brevicornu rosmellitum, Mycetophila eppingensis, M. deflexa, Phronia carli (the two 

 latter previously misidentified as M. gratiosa Winnertz and P. longelamellata 

 Lundstrom respectively). A new name is also proposed for a homonym: Exechia 

 macula for E. maculipennis (Stannius). Dynatosoma norwegiense Zaitzev & 0kland is 

 indicated to be thoracicum sensu Landrock of the checklist. Sciophila quadriterga 

 Hutson is a synonym of S. thoracica Staeger. Lectotypes are designated for 

 S. thoracica and Boletina sciarina Staeger. A lectotype designation for Mycetophila 

 bicincta Staeger is considered inappropriate. The seven species additional to the 

 Royal Entomological Society Handbook dealing with part of this group are figured. 

 New British records of 27 species are provided, one species is new for Ireland and 

 two species are new for the Channel Islands. 



Introduction 



In the recent new checklist of British Diptera (Chandler, 1998c). 17 species of 

 fungus gnats were listed as "added by Chandler (in preparation)" and the existence 

 of several undescribed species was also mentioned. One of the latter has already been 

 described (Chandler, 1999) and most of the others are described here: the Docosia 

 and Cordyla species will be dealt with elsewhere. Comment is given on the British 

 status of the species newly added in the checklist and also on the three species added 

 in Recording Scheme reports (Chandler, 1997, 1998a) and one added in an 

 Exhibition Report (Chandler, 1994b). 



Of the species dealt with here, all of those belonging to groups covered in the 

 Handbook by Hutson et al. (1980) are figured and their diagnostic characters 

 indicated. For the Mycetophilinae, where there is not yet a Handbook, only the new 

 species and one newly recorded for the Palaearctic Region are treated in this way. 



Material listed is in the collection of the author or other collectors unless stated 

 otherwise. The Museums involved are abbreviated as follows: BMNH = Natural 

 History Museum, London; ETHZ = Eidgenossische Technische Hochschule, Zurich; 

 NMS = National Museums of Scotland, Edinburgh; OXUM = Oxford University 

 Museum; ZMUC = Zoological Museum of the University, Copenhagen. 



Ditomyiidae 

 Symmerus nobilis Lackschewitz (Figs 1—4) 



This was reported (Chandler, 1997) as a surprising addition to the British list, based 

 on three males from the same Scottish locality. It is easily distinguished from the 

 widespread species S. annulatus (Meigen, 1830), which was present at the same site, on 

 colour characters and the structure of the genitalia (Figs 1— 1). The figure of the female 

 is based on a Swiss specimen and the ovipositor of 5. annulatus (Fig. 5) is figured for 

 comparison. S. nobilis is widespread in Europe but apparently always scarce. 



