300 The Large Poplar Longhom 



it is little known, its occurrence according to Fowler (i) 1 being very rare. 

 However, in certain areas in the neighbourhood of Aboyne, Aberdeen- 

 shire, I have found this species present in large numbers doing great 

 damage among the young poplars of natural growth. In gardens, too, 

 in the village of Aboyne where poplars have been planted for ornamental 

 purposes, these have been completely destroyed through the repeated 

 attacks of S. carcharias. 



It was in these areas that the study of the life history of the insect 

 was carried out by experiment and field observations, while the ana- 

 tomical and microscopical studies and some breeding experiments were 

 undertaken in Dr Stewart MacDougall's laboratory in Edinburgh 

 University. 



Characters of the Genus Saperda. 



The genus Saperda is singled out by Fowler (2) from the other Lamiidae, 

 the sub-family to which it belongs, by the following characters- 

 Femora not or scarcely clavate. 



Thorax without lateral spines. 



Tarsal claws simple. 



Anterior coxae distant. 



Antennae ringed with white. 



Mesosternum not protuberant between intermediate coxae. 



Form elongate. 



Antennae eleven jointed. 



In view of the work of Gahan(3) and Felt(-i) this key of Fowler's, in 

 which he places the genus Saperda under the forms with simple claws, 

 requires modification. 



Those two workers point out that, although simple claws are present 

 in some species, e.g. Saperda populnea, others possess bifid claws. In 

 the species which possess bifid or compound claws these are confined to 

 the male sex. The bifid claws sometimes are found in the first two pairs 

 of legs as in Saperda carcharias, sometimes only in the first pair of legs 

 and sometimes only in the second pair of legs. According to Le Conte, 

 who was the first worker to draw attention to the presence of these claws 

 in the genus Saperda, it is only the inner or anterior claw of the tarsus 

 that is toothed, or bifid. 



The following is Fowler's (l) description of Saperda carcharias adult: 



One of the largest and most conspicuous British Longicorns, black, clothed with 

 yellowish or ashy-grey pubescence which is thicker and longer on the under surface 



1 The numbers in brackets refer to the "Literature," p. 342. 



