NEMATUS LEUCOSTIOTUS. 189 



and tarsi, curved spurs, and much longer third cubital 

 cellule, sufficiently distinguish this insect from its allies. 



The larva of this species lives in folded-down leaves 

 of Salix viminalis, 8. pentandra, and S. vitellina, if not 

 on other willows. The leaf is folded down on the 

 under side, the fold extending, as a rule, the entire 

 length of the leaf. The egg is deposited at one end 

 of the fold embedded in the epidermis ; the leaf is 

 bent down by the imago, but how this is done I do not 

 know. I have, however, noticed that the leaf seems 

 to be glued down, as a number of small glutinous 

 shining points are seen along the edge of the fold on 

 the leaf itself, and these dots are especially noticeable 

 when the leaf is young and growing. When the leaf 

 is young the two surfaces of the fold touch one another, 

 but as the larva grows it gets more open, and frequently 

 becomes tenanted by Aphidce as well as by roaming 

 lepidopterous larvae. Sometimes there is only one fold, 

 but not rarely there will be one on each side of a leaf. 



The larva commences feeding by eating the epi- 

 dermis, at first near where the egg was placed, then in 

 scattered places over the fold, and ultimately over the 

 entire leaf, but the leaf is never devoured quite through. 

 It carries the body somewhat arched, the anus touching 

 the leaf. In the autumn; when it becomes full-fed, it 

 drops to the ground, where it spins a light brown 

 cocoon, in which it remains unchanged till May, when 

 it becomes a greenish pupa, which state lasts from 

 ten to twelve days. 



When young the larva is whitish without any very 

 distinct markings. At the third moult the head is 

 flattish, sloping towards the mouth ; in breadth it is 

 about the same as the second segment, the colour 

 blackish, fuscous-yellow, or brownish-yellow, with the 

 mouth and eye-spots black. The legs are greenish- 

 white with brown claws, over each is a broad black 

 band; the ventral legs are white. The body is 

 greenish -white, the food canal giving it a darker, often 

 a decidedly green, tint. The skin is beset with many 



