UK. I INI NAI IIISI . IV 2001 



hospitality during my stay in Wales. Dr Jindrich Rohacek (Opava, Czech Republic) 

 is thanked for sharing useful, unpublished information. 



References 



Carlcs-Tolra, M. 1990. New species and records of Sphaeroeeridae (Dipt.) from Spam. 



Entomologist's Monthly Magazine 126: 33 46. 

 Deeming, J. C. 1995. Diptera (True Flies) from the Kcnfig National Nature Reserve. 



Glamorgan. National Museum of Wales: Entomology Scries 4: 1-113. 

 Marshall, S. A. & Rohacek, J. 1984. A revision of the genus Telomerina Rohacek (Diptera, 



Sphaeroeeridae). Systematic Entomology 9: 127 163. 

 Marshall, S. A. & Smith, I. P. 1992. A revision of the New World and Pacific Phthitia Enderlein 



(Diptera; Sphaeroeeridae; Limosininac), including Kimosina Rohacek. new synonym and 



Auhertinia Richards, new synonym. Memoirs of the Entomological Society of Canada 161: 



1-83. 

 Marshall, S. A. & Smith, I. P. 1993. A revision of the Nearctic Pseudocollinella Duda (Diptera: 



Sphaeroeeridae). Canadian Journal of Zoology 71: 835-857. 

 Munari, L. 1992. New records of lesser dung flies from Italy and distributional notes on 



Opacifrons jorlii Carles-Tolra, 1990 (Diptera: Sphaeroeeridae). Bollettino del Museo civico 



di Storia naturale di Venezia 41 (1990): 225-229. 

 Pitkin, B. R. 1988. Lesser Dung Flies. Diptera: Sphaeroeeridae. Handbooks for the Identification 



of British Insects 10(5e): 1-175. 

 Rohacek, J. 1982. Revision of the Subgenus Leptocera (s. str.) of Europe (Diptera. Sphaeroeeridae). 



Entomologische Ahhandlungen. Staatlichen Museum fur Tierkunde in Dresden 46: 1 4. 



SHORT COMMUNICATION 



Behavioural observations of Philanthus triangulum (Fab.) (Hymenoptera). — 



Philanthus triangulum (Fab.), the European bee wolf, is a species of solitary wasp 

 found throughout Western Europe. Over the past 7-8 years it has been undergoing a 

 population resurgence after a period of reduced numbers. A newly established colony 

 of P. triangulum was discovered in the grounds of St Peter's Hospital. Chertsey . 

 Surrey. This colony had probably only been present for one to three years before the 

 date of discovery (June 1996). The colony was observed to establish on the same site 

 over the next two years and in 1998 a new colony was observed in a separate location 

 approximately 150 metres from the first. Due to its small size (10-20 individuals) this 

 probably established in 1998, possibly as an offshoot of the first colony. 



The first colony was the focus of a short period of field study during the summer of 

 1998. During the period of study, on several occasions (4-5) two wasps were 

 observed using one nest entrance. Each wasp would open the entrance itself (i.e. clear 

 the plug of soil put in place to prevent parasitism), and close the entrance after it. 

 The wasps would remain in the nest burrow together and then leave separately. 

 There was no evidence of aggression, as was sometimes seen when one female entered 

 another's nest in order to plunder paralysed worker bees from the nest. 



There are several possible explanations for this behaviour. The females could have 

 been sharing nest entrances, but have had separate nest burrows underground. This 

 is the most likely explanation, as many other species of solitary wasp show this 

 behaviour. The nest sharing could have been accidental, due to misidentification of 

 nest sites. This was observed occurring at several different burrows so this is less 

 likely. Alternatively the females could have been exhibiting some degree of social 

 behaviour. No papers so far found have described any of these behaviours 

 for P. triangulum. Whichever is true this novel behaviour is worthy of extra study. — 

 Jason Moore, Selwyn College, Cambridge CB3 9DQ. 



