INSECT VAIMETY. 125 



remember tliat it was very early, and before actual dusk, on a hill, 

 or rising- ground rather, some two or three miles from the town, 

 near Stoke Court, where I saw many of these moths, the only time 

 I ever saw them alive, flying- up and down and very fast, and hard 

 to catch, near or above the top of an old-fashioned high hedge, on 

 the side of a wide, grassy lane. I could not help being struck 

 by the curious stridulous sound they made as they flew." Here 

 the ffregrariousness of the insects is noticed. 



Next the noise proceeds from the male. Dr. Buchanan 

 White, writing from Perthshire, says : — " On the evening of the 

 '28th May^ when mothing in the oak wood surrounding my 

 house, I noticed what I thought was a beetle, flying round a 

 small oak, and giving vent all the time to a sharp, quick sound, 

 very similar to that produced by the Scottish longicorn beetle 

 Astinomus, when held between the fingers. Though I failed 

 to catch this individual, I was more successful with another 

 which was behaving in the same manner. When in the net the 

 sound ceased, and I saw to my astonishment that the insect 

 was a moth." This proved to be a male Silver-lines. On the 

 same evening Dr. White again went out to the oak wood, and 

 captured another specimen in the act of "squeaking." 

 " The sound was quite distinct at a distance of ten feet 

 or more. Next morning I treated him (it was a male) in the 

 same manner as I had the first specimen, and with a similar 

 result. I found that a good imitation of the sound may be made 

 by rubbing the point of a knitting-needle on the closed blade of 

 a clasp-knife. I have since taken another specimen, also a male, 

 flying round an oak, but not producing any noise." 



Then the note is employed during courtship, and marks the 

 pairing-time of the moth, as I had myself opportunity of 

 witnessing some years since, when spending a su.mmer sketching 

 at St. Catherine's Ferry, Argyleshire. On one of those fine 

 days after the protracted spring rains that occur in the beginning 

 of June, wending home about sunset, on the skirts of a newly- 

 leaved oak shaw, I was suddenly arrested by a novel and loud 

 succession of twitters in the dusk air, and on looking up saw a 

 male and a female Silver-lines Moth, which came fluttering- down 

 from the foliage, and were toying just in front of me. 



Now, as to the production of this sound, analogy would refer 



