( 393 ) 



CHAPTER XIX. 



RHYNCHOPHORA (continued) Family CURCULIONIDAE. 



(Weevils.) 



owing 



The P.ilni Weevil (Rhynchophorus 



ft'i-nigi'in'its, Oliv.). India. 



THK weevils for the most part are easily distinguished beetles 

 to the head being prolonged into a beak or rostrum of varying length, 

 upon which the elbowed and clubbed antennae are borne. The antennae 

 often fold back into grooves placed in the sides of the rostrum. Some of 

 the forest species have also a definite bulk)- shape, the elytra being very 

 convex, and the insect reaching to over fifty millimetres in size. A large 

 number are, however, very much smaller, some only five to six millimetres 

 in length or thereabouts. 



The beetles vary in coloration, dull 



browns and blacks pre- 

 Beetle. dominating in the forms 



which tunnel into trees. 



Grey is common in the family, and red, pink, 

 yellow, and green forms are also present, 

 this bright coloration often depending on the 

 pubescence or scales or a meal}' covering 

 which clothes the insect. The third tarsal joint is frequently heart-shaped. 

 The small eyes are situated at the base of the rostrum, the mouth at the tip ; 

 the rostrum varies greatly in shape and length and in position, in some being 

 projected outwards more or less in the horizontal plane ; in others, such 

 as, e.g., the cryptorhynchids, being directed dowmvards in the vertical 

 plane. The antenna has the elements of the scolytid antenna in it, con- 

 sisting of a basal segment, the scape, six or seven shorter segments which 

 represent the funicle, and three or four other broader segments which form 

 the club. The prothorax is usually well developed, and the elytra cover the 

 body completely in most cases, and are bent down to a certain extrnt over 

 the sides. The males are often readily distinguishable from the females by 

 their smaller size, elongate front legs, and the different shape and length 

 of the rostrum. 



The larva of forest curculionids is usually a soft, white, curved, legless 



grub with a yellow or brown head, strong mandibles, 



Larva. and corrugated segments to the body. In some forms 



the body is thickest posteriorly, in others across the 



centre, the grub tapering at both ends ; tubercles are sometimes present on 



the bodv. 



