16 CUECULIOyiD^. 



Poepalosomus) some of the species are capable of producing more 

 striking secretions in the form of white wax-like flocculent ex- 

 crescences, similar in character to those of various Coccid.e 

 and ruLGORiD.=E. 



Sexual Dimorphism. 



There are comparatively few instances of very marked sexual 

 disparity iu the CuRCULioxiD-i), and there should rarely be any 

 difficulty in associating the sexes of any given species. In 

 certain genera, especially among the more rotund wingless 

 terrestrial forms, the difficulty lies in the opposite direction, 

 and in the case of such insects as Blosyrus or Brachycerus there 

 are often no reliable external characters by which the sexes can 

 be discriminated. 



The sexual distinction that is perhaps of the most general 

 occurrence is to be found in the lirst ventral segmeut, -which is 

 more or less strongly impressed m the middle in the male, while 

 in the female it is flat or even shghtly convex ; but to this there 

 are very numerous exceptions. In those forms that have a 

 comparatively short rostrum, this organ is rarely different iu 

 the two sexes (though occasionally the geuae have a lateral 

 process iu the males), but the females are generally larger and 

 liave the sides of the elytra more strongly rounded, while tlie 

 fifth ventral segmeut is frequently more pointed in this sex. 

 When the rostrum is elongate, it nearly always exhibits good 

 sexual characters. If there is any difference in size, that of the 

 female is longer and more slender ; while when the length is 

 equal, the rostrum of the male is nearly always more coarsely 

 punctured and the punctures extend nearly or quite up to the 

 apex, whereas in the female the apical half, or more, is very finely 

 punctate or even quite smooth. 



The inequality in the length of the rostrum is most marked in 

 a South African species of Antliarrliinus that oviposits in the 

 cones of Cycads ; in the male this organ is about as long as the 

 head and prothorax, while in the female it is nearly three 

 times as long as the whole body. In some Calaudrine genera 

 {Protocerius, Ehijnchojjhorus) the rostrum of the male is dis- 

 tinguished by a row of tubercles or a crest of hairs on its upper 

 surface, while in Ehina it has a dense fringe of long hairs beneath. 



Differences in tlie form of the antennae are not rare. Tor 

 example, in Eurrhynclms (Australia) and Cylas the solid club is 

 uiuch longer in the male ; in Gercidocerus the club is enormously 

 elongate transversely in the male, so that the anteuna has the 

 sliape of a pickaxe ; in some Indian Apoderus the terminal joint 

 of the male is produced into a curved process ; and in Mecomastyx 

 (New Caledonia) the scape of the male may be anything from 

 t) to 12 times as long as that of the female. 



There are certain instances, as in the very large Indian weevils 

 of the genus Cyrtotrachelus, in which the front legs of the males 



