v RHYNCHOPHORA CURCULIONIDAE 2QI 



about 20,000 known species, and yet a large portion of the 

 species yearly brought from the tropics still prove to be new. 

 The rostrum or beak exhibits excessive variety in form, and is in 

 many cases different in the sexes ; in this case it is usually longer 

 and thinner in the female. As the rostrum is one of the chief 

 characters by which a member of the family may be recognised, 

 it is necessary to inform the student that in certain forms (the 

 Australian Amycterides, e.g^) the organ in question may be so 

 short and thick that it is almost absent. In these cases the 

 Insect may be identified as a Curculionid by the gular area being 

 absent on the under side of the head, and by the concealment of 

 the palpi. The tarsi are usually of the same nature as those of 

 Thytophaga, already described, but the true fourth joint is less 

 visible. In the Brachycerides this joint is not present, and the 

 third joint is not lobed. The palpi are flexible and more or 

 less exserted in a very few species (Ehynchitides) ; in Ehinoma- 

 cerides there is also present a minute labrum. The front coxae 

 are deeply embedded, and in many forms the prosternum is 

 peculiar in structure ; the side-pieces (epimera) meeting at the 

 back of the prosternum in the middle line. This, however, is 

 not universal in the family, and it occurs in some other beetles 

 (e.g., Megalopodides of the Phytophaga). The larvae are without 

 legs. They are vegetarian, the eggs being deposited by the 

 mother-beetle in the midst of the food. These larvae may be 

 distinguished from those of Longicorns by the general form, 

 which is sub-cylindric or rather convex, not flattened, and 

 more particularly by the free, exserted head, the mouth being 

 directed downwards ; the attitude is generally a curve, and the 

 anterior part of the body is a little the thicker. No part of 

 plants is exempt from the attacks of the larvae of Curculionidae ; 

 buds, twigs, leaves, flowers, fruits, bark, pith, roots and galls 

 may each be the special food of some Curculionid. Certain 

 species of the sub-families Rhynchitides and Attelabides prepare 

 leaves in an elaborate manner to serve as food and dwelling for 

 their young. If young birches, or birch bushes from 5 to 10 

 feet in height, be looked at in the summer, one may often notice 

 that some of the leaves are rolled so as to form, each one, a little 

 funnel. This is the work of Rhynchites (or Deporaus) letulae, a 

 little Curculionid beetle (Fig. 149). An inspection of one of 

 these funnels will show that it is very skilfully constructed. The 



