INTRODUCTION. 23 



No sort of adhesive appears to be used in the construction of 

 the rolls, but the curling of the leaves is ettected by patient and 

 continuous pressure, while they are prevented from unrolling 

 by an ingenious method of tucking in the ends and the free 

 edge. lu every case the \\'eevil weakeus either the leaf-stalk or 

 the point of attachment of the roll by nibbling, so that in a few 

 days it falls to tlie ground, and the mature larva eventually enters 

 the soil to pupate. 



It is somewhat remarkable that wliile some of the European 

 lihyncJiites, such as li. hetula% L., have evolved this elaborate 

 method of providing for their young, other species of the same 

 genus have adopted a much more simple procedure ; for example, 

 the larvae of K. cupreus, L., and H. bacchus, L., feed merely ou 

 the pulp of certain fruits ; those of H. auratus, Scop., live in the 

 kernels and those of li. icosandrice, Scop., and B. interpunctatus, 

 Steph., in the buds of their food-plants. What may perhaps be 

 regarded as a first step in the direcrion of a leaf-rolling habit is 

 to be found in certain OTiORRHrNCiiiN^. For example, the 

 common Indian Episomus lacerla, F., lays a batch of eggs on a 

 leaf, which is folded over so as to cover them, the edges being 

 gummed together by means of a sticky secretion ; the larvae on 

 hatching gnaw through the leaf and drop to the groinid (Fletcher, 

 ' Some South Indian Insects,' p. 327). W. Dwight Pierce records 

 an almost identical habit in the case of the North American Gom- 

 psus auricephalus. Say (Proc. Ent. See. Washington, xviii, 1916, 

 p. 7), and so have Osborn and Mally for Ei>ica'rus imbricatus. 

 Say (Proc. Iowa Ac. Sci. iii, 1896, p. 207), and it is probable that 

 this is not an unusual method of oviposition in the subfamily. 



The habits of the larvse are very varied, and every portion of 

 a plant is liable to attack, as the following brief list will sliow : — 



Leaves (exrernally) : — Hi/pera, Oonlatus, C'iouvs, FJu/tohius. 

 ,, (rolled) : — Bhynchites, Attelahus, Apoderus. 

 ,, (mined) : — lUiynclicenus, Rhamplms, Bracliyonyx. 

 Flower-heads: — Larinus, Apion, Anthonomus, etc. 

 Fruits and Seeds : — Apion, Sibinia, Nanopthyes, Balaninvs^, 



C'ryptoryhynchas, Calandra, and numerous other genera. 

 Stems of Herbaceous Plants : — Apion, LLvtis, Cenihonhyn- 



chus, Alcides, Burls, etc, 

 I'ree-trnnks : — Hylohivs, many CRYPTORRHVNCHiN^ii, JSpalns, 



Rhyncliophorus, many Cossoninje, etc. 

 lioots: — Tanymecus, many OxiORRHYNCHlNiE, /Si^oHcs, Brachy- 



cerus, many CleoniNjE, etc. 

 Tubers : — Cylas, Euscepes. 



From the foregoing statement it will be seen that the a ast 

 majority of Curculionid larva) are internal or subterranean feeders, 

 and it is probable that the loss of the legs has resulted from their 

 sedentary mode of life. Tlie adoption by a few genera of the 

 liabit of feeding externally ou leaves may thus be a nu;re recent 



