1870.] 2o'3 



the head still keeping its relative size, growing bigger as the body grows, until the 

 larva is about lialf-grown ; then it begins to feed between united leaves, and the 

 figure assumes other proportions. When full-fed, the larva is about three-quarters 

 of an inch long, slender in figure, the head flattish and as wide as second segment' 

 tlie body stoutest about seventh, ei::;hth, and ninth segments, thence tapering both to 

 the head and the tail ; the anal pair of feet stretched out behind ; the skin very 

 glassy and glistening though somewhat wrinkled : the colour of the head pale orange- 

 brown, the antennal papilltc paler still and tipped with black, the mouth brown, the 

 ocelli black, and a black spot at some distance behnid them on the side of the head ; 

 the back as far do^vn as the spiracular region is of a rather brownish-olive green, the 

 dorsal line darker olive green : an undulating row of internal darker blotches runs 

 along in an interrupted manner a little above the spiracles, showing plainly through 

 the translucent skin ; the spiracles very small and inconspicuous, being of the ground 

 colour ringed with brown ; below them the rest of the side, and the belly and legs, 

 are of a uniform tint of very pale watery-olive greenish ; there is a fine hair from 

 each tubercular situation. 



By the end of the third week in July, that is after feeding about six weeks, the 

 larva spun up, forming for itself a cocoon in a very clever manner from a leaf of 

 hornbeam ; taking as its standpoint a spot nearly in the centre of the midrib, equi- 

 distant that is from the tip of the leaf and the footstalk, and cutting through the 

 midrib itself at that point, but leaving about one-eighth of an inch of the leaf uncut 

 to serve as a footstalk to its cocoon, it proceeded to make two semi-circular cuts 

 towards the tip of the leaf, but at a slight inclination towards the left, so that further 

 on the midrib was again severed by the right cut, and the place where the two cuts 

 met was on the left edge of the leaf (looking at it, that is, from above) not very far 

 from the tip ; using then the midrib of this semi-detached circular piece as the back- 

 bone of its structure, the larva bent down the two sides of the piece, and fastened 

 them together all along their edges ; the cocoon thus formed is rounded along the 

 upper outline, and with its sides rather flattened till they meet in the shai*p lower 

 edge. — Id. 



Description of the larva, ^c, of Fterophorus diclirodactylus. — On .Tuno 8th, 

 1S75, Mr. John Sang, of Darlington, very kindly sent me several larva; of this species, 

 in various stages of growth, mining witliin stems of Tanacetum vulgare. 



As soon as their food began to wither, fresh sprays of tansy were provided for 

 the larva), which, often as this occurred, readily left the old stems to commence mining 

 into the fresh ones. 



The mouth of the mine is generally between the axil of a leaf and the stem, 

 with a few silk threads spun from one to the other, just above it, among which the 

 dark olive or blackish frass becomes entangled, as the larva pushes it out from time 

 to time in its course head downward ; the quantity there increases more and more, 

 xmtil at length the accumulation becomes very conspicuous, and betrays the presence 

 of the larva. 



Wliile immature, the larva is darker in its colouring than it afterwards becomca ; 

 it is blackish-green when not more than a quarter of an in(;h long, glaucous-grccn 

 with grey stripes when about three-eighths in length ; but, when full-grown, the larva 

 measures a little more than half an inch, its figure moderately slender, cylindrical, 

 and tapering a little from the third segment to the head, which is rather rounded ; 



