4 TORTRICINA. 



first, the act of the larva itself; secondly, the force exercised by 

 the contraction of the silk : there is otherwise no accounting for 

 the extraordinary folding and bending of stubborn leaves, ob- 

 viously beyond the unassisted strength of the minute larvae. 



The duration of life in the larva state varies considerably, 

 according to the species, those which are internal feeders being 

 usually longest in coming to maturity. The reason for this is 

 evident. For such as feed on leaves it is requisite they should 

 be full-grown before the fall, whilst those living internally are 

 urged by no such necessity; and many of these latter may be 

 found in the winter and early spring months, if not actually 

 feeding, still in the larva state. 



The larvse themselves, at least of those most commonly met 

 with, are so similar to each other, as to render their discrimina- 

 tion difficult, if not altogether impossible, without the most 

 careful attention. They are mostly of plain and uniform colours ; 

 and besides the roundish elevated spots (which are equally cha- 

 racteristic of the Tineina larvae), they are deficient in markings, 

 to enable the student to distinguish them ; nevertheless, they 

 are very interesting, but must be studied before we can expect 

 to become acquainted with their habits ; and we would urge on 

 those who have the time to observe them, to note down carefully 

 every fact that comes before them, relative to these insects in 

 their larva state; for until we are much better acquainted with 

 the preparatory states than at present, we must not hope to see 

 a natural grouping of the species. 



The pupa state, like that of the larva, also varies in duration : 

 in some species a lew days are sufficient to develope the imago, 

 in others it requires months ; but we have not sufficient data on 

 which to base any sound or general conclusions. 



GENERAL CHARACTERS. 

 IMAGO. 

 Head tufted with hairy scales above; the tufts inserted over the 



eyes, and meeting in a ridge on the vertex. 

 Eyes always compound, large, semiglobose. 

 Ocelli frequently (always?) present, inserted over the eyes, but 



partly concealed by the tufts on the head. 

 Palpi always three-jointed ; middle joint longest (except in Sarro- 



thripa, where it is of the same length as the apical) ; apical 



joint never recurved upwards. 

 Maxilla usually not longer than the palpi (in Sarrofhripa thrice as 



long) ; when at rest, wound up convolutely at the base of those 



organs. 

 Antennce almost invariably simple (in Amphisa pectinated, in Ditula 



