50 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY 



7. Sinodendron cylindricum^ L., and related 

 Lamellicorns. 



{With Plate.) 



By R. Stewart MacDougali,, M.A., D. Sc, F.R.S.E., Honorary 

 Consulting Entomologist to the Society. 



Sinodendron cylindricwn is a rare beetle in Scotland, and the 

 finding of it is worthy of record. The record is mentioned here, 

 and a description given of the beetle and its larva, in order 

 that Scottish foresters may be made familiar with the species 

 which is, perhaps, not quite so rare as is believed. 



While searching in Peeblesshire for quite a different insect, on 

 7th October, with Mr James Munro, B.Sc, we came on a 

 standing ash tree some 70 years of age and quite dead. The 

 appearance of the bark and the wood exposed in places that 

 had lost their bark, suggested that a closer examination might 

 prove profitable from an entomologist's point of view. The outer 

 portion of the exposed wood was in places so crumbly that these 

 yielded easily to pressure with a chisel, and almost immediately 

 Mr Munro exposed a large Sinodendron larva. A little further 

 work exposed both an adult beetle and several larvae. Permis- 

 sion to make still further and severer examination of the tree 

 was given by the proprietor, and on a return visit on 23rd 

 October a large number of Sinodendron larvae and adults were 

 got, these being taken from the trunk of the tree at a height 

 from 4 to 10 feet. The trunk above this was left for future 

 examination. 



The larvae were in all stages of growth, from quite small larvae 

 up to larvae of full size like the one shown in Plate VI., Fig. \b. 

 The beetles, which were of both sexes, were quite fresh beetles. 

 They had not yet made their exit into the open, but were lying 

 where they had completed their development in chambers 

 hollowed out in the wood ; the more solid wood was hidden 

 under a layer of powdery crumbled frass and sawdust. In this 

 powdery material the fauna was a scavenger one — numerous 

 slaters and millipedes and worms and scavenging mites all 

 aiding to complete the reduction of the tree. Under loose and 

 easily puUed-off sheets of bark there were numerous sheltering 

 Pollenia rudis and Cyrtoneura pabuloriim^ two muscid species. 

 Not many yards away from this ash was an old elm tree that 



