156 THE ZOOLOGIST. 
are enclosed in their tough cocoons, they are safe from the 
attacks of avian enemies, but in this he is not correct. During 
the autumn of 1911, in a larch-wood which was frequented by 
Pheasants, I found that these birds (they received no artificial 
food) had scratched over all the litter beneath the trees which 
had been attacked by Nematus erichsoni in search of the cocoons 
of this insect. This bird would certainly be of great value in 
reducing the sawfly if present in sufficient numbers. 
The Short-tailed Field-Vole (Microtus agrestis) is also of use, 
for it extracts the larve from their cocoons during the winter 
months. Prof. Hewitt calculated that at Thirlmere, in the winter 
of 1907-8, these rodents had destroyed 25 per cent. of the larve. 
I have taken as many as sixty empty cocoons from a few inches 
of a Vole’s run. Any undue increase of the Field-Vole is, how- 
ever, not desirable, for the damage which this animal can do to 
vegetation, when present in large numbers, is well known. 

NOTES AND QUERIES. 

AVES. 
Early Appearance of Chiffchaff in Shropshire —Between 6 am. and 
7 a.m. on March 14th a Chiffchaff was in good song close to my 
house. I hear from Mr. H. E. Forrest, our authority for this county, 
that several other early records have also come to hand. This is 
practically a fortnight earlier than usual for Salop, and nearly a 
month sooner than in last year, and for comparison I give personal 
records of the earliest appearance of this species in this same district 
in former years :—1903, March 25th; 1904, April 8th (absent from 
home since April 2nd); 1905, March 23rd; 1906, April 1st; 1907, 
March 28th; 1908, April Ist; 1909, April 2nd; 1910, March 21st; 
1911, April 10th (exceptionally late date, but the first record for 
Salop generally); 1912, March 14th. It would be of great interest 
to know if the species has appeared exceptionally early in other 
counties generally, or the area covered by this early stream of migra- 
tion —J. Stree Exuiorr (Dowles Manor, Shropshire). 
