244 BR. J. ENT. NAT. HIST., 13: 2001 



BENHS FIELD MEETINGS 



Burnham Beeches, Slough, Berkshire, 18 October 1997 



Leader: Ian Sims. — Half a dozen members met the leader at the main car park at 

 Burnham Beeches for this field meeting. It was an overcast and cool day but glimpses 

 of sunshine brightened the morning session. The main objective was to search for 

 evidence of Phyllonorycter mespilella (Hiibn.). Mines believed to be of this species in 

 whitebeam had been collected here the previous autumn but no adults were reared. 

 Burnham Beeches is a large area of broadleaf woodland that is managed by the City 

 of London Corporation. Within its bounds are isolated areas of heath where ling 

 {Calluna vulgaris) is the most abundant heather species and cross-leaved heath (Erica 

 tetralix) also grows. Common cow-wheat (Melampyrum pratense) is a widespread if 

 sparse member of the forest ground flora. There are several lakes, drainage streams 

 and marshy areas, but the chief entomological attraction of the site is its abundance 

 of dead wood. 



The morning was spent in the woods and heaths to the north and east of the car 

 park. Here an example of Nycteola revayana (Scop.) (oak nycteoline) was put up 

 from heather in a heathy area known as "the moat". Although an early date for 

 collecting fungal-feeding tineids, several birch polyporus fungi (Piptoporus betulinus) 

 with obvious signs of feeding by lepidopterous larvae were taken. Subsequently these 

 yielded examples of the rare Nemapogon variatella (Clem.) and the common N. 

 cloacella (Haw.). Other members of this family, reared in 1998 from material 

 collection on this meeting, included Morophaga choragella (D. & S.) and Triaxomera 

 parasitella (Hub.), both from the fungus Inonotus dryadeus on beech, and N. 

 wolffiella (Karsh. & Neil.) reared from Hypoxylon multiforme on dead birch logs. 

 While collecting these an overwintering case of Coleophora artemisicolella Bru. was 

 found. This species is not mapped for VC24 in MBGBI, 3. 



Leaf miners were few and far between. It was not clear if we were too early or late 

 in the season for these, but few vacated mines were seen. However, several members 

 of our party found sufficient mines of Stigmella tityrella (St.) in beech (Fagus 

 sylvatica) to be worth retaining some and attempting to rear them out. Those trying 

 this were advised to take some beech leaf mould for the larvae to pupate in and this 

 tactic proved successful. Mines of a phyllonoryctid were found in whitebeam. These 

 matched the description of P. mespilella, but material reared the following spring by 

 Dennis OKeeffe proved they were P. sorbi (Frey.). 



Lunch was taken at the snack bar back at the car park, where a dog rose (Rosa 

 canina) was seen growing next to our table. The leaves of this plant were riddled with 

 larvae of Ectoedemia angulifasciella (St.). After lunch the party moved to some ponds 

 in woodland to the south of the car park. En route, green islands were noted in fallen 

 leaves of aspen (Populus tremula). These proved to betray the presence of 

 E. argyropeza (Zell.) larvae mining within the leaf petioles and just starting 

 to feed in the base of the leaves. In the past I have found this species 

 quite late in the year, many other stigmellids having vacated their mines by 

 the time argyropeza is feeding. Hence the uncertainty as to whether the 

 leafminer season was late or early, on account of the lack of mines for 

 other species. It later transpired that 1997 was a poor season in this part 

 of the country for leafmining Microlepidoptera. 



On arrival at the ponds several members of the group spent some time recording 

 aquatic invertebrates. Interesting records included: Coleoptera — several examples of 



