Insects, etc., Injurious to Nuts. 



313 



When very abuudant on the sweet chestnut the boxes should be 

 collected and burnt, if on youno; trees. 

 On old ones it does but little harm. 



References. 



(1) Fishcr-Schllch. ■ Manual of Forestry,' vol. V., p. 198 (1895). 



(2) Theohahl, F. V. Animal Pests of Forest Trees, Journal S. E. Agri. Coll., 



No. 13, p. 185 (1904). 



Ill._TO WALXUT. 



THE DUSKY-VEINED WALNUT LOUSE. 



( rff/rlnidcs J/'i/l" ndis. Frisch.) 



This is one of our most beautiful aphides, and it is strange that 

 such a conspicuous insect's life-history sliouhl remain still unknown. 

 It is well figured by Buckton (1 ). 

 I observed it for nine or ten 

 years regularly (2) working 

 upon some large walnut tree-- 

 at Kingston - on - Thames ; but 

 although present in plenty, it 

 never increased sufficiently to 

 do any serious harm to the trees 

 until 1894, when this and other 

 pests were most destructive. 

 The earliest note of the creature's 

 appearance upon the walnut leaf 

 was the 1st of July ; in 1894 

 none were observed until the 

 10th of July. In all instances 

 the form of aphis first observed 

 upon the leaves was the ir'nujcd 

 viviparous female. The follow- 

 ing is copied direct from my 

 notes : — " These plant lice are 

 always to be found on the upjier 

 surface of the walnut leaves, 

 and in two rows close to the raid 



rib (Fig. 212). The winged females usually settle and fix themselves, 

 before reproducing, in patches of fourteen to twenty, seven or ten 

 on each side of the mid rib, with their heads invariably pointing 



a. iii.—niv. HUSKY- 

 Kymiihs ou leaf and just hatclie 

 left of nymphs. 



(Enl; 



