SPREAD OF A RARE ROVE BEETLE IN SCOTLAND ro! 
It has somewhere been said that the known distribution 
of a rare beetle in this country indicates, not so much 
the true range of the insect, as the location of the members 
of the little band of British entomologists who work the 
group. As long as the study of Coleoptera appeals only 
to a few this statement will always contain an element of 
truth, but the lack of coleopterists does not account for 
the gap of forty years in our knowledge of the occurrence 
of this insect in Scotland. PP. crenata is a well-defined, 
unmistakable species of fair size (4-5-5 mm.), and it could 
not readily be passed over in its own particular habitat, 
which is under the loose bark of various trees. Yet, until 
1907, when Dr Chaster re-discovered it, the insect was 
practically unrepresented in the collections of British 
coleopterists. Some of the localities in which it has recently 
been found were the favourite hunting grounds of 
experienced coleopterists, who could scarcely have missed 
it had it been present in their day. One of the Renfrew- 
shire localities, for instance, was much frequented by the 
late Morris Young, but there are no examples of the species 
in his collection in Paisley Museum. The Linlithgowshire 
locality was also well worked in the middle of last century, 
but no one seems to have found it there until it was 
discovered in 1913 by Dr Cameron. The same remark 
applies to the Lanarkshire locality. 
These facts, I think, warrant the inference that the insect 
was very rare or, at any rate, extremely local and restricted 
in its distribution in Scotland at and after its discovery by 
Turner, but that within the last thirteen years it has become 
a great deal more plentiful and more widely distributed, so 
that in it we have the pleasure of seeing a rare species in 
the process of becoming commoner instead of still more 
rare as, unfortunately, is more often the case. It will be 
noticed that the counties in which it has been found form 
a fairly compact group in the centre of Scotland, and, if 
one cared to assume that Mid Perth was the only station 
for the insect in Turner’s day, a plausible attempt might 
be made to trace the direction of its gradual spread to the 
other counties in which it is now found. Apart from this 
