HYTOPHAGA CERAMBYCIDAE 287 



There are numerous Longicorns that bear a great resemblance 

 in form and colour to Insects to which they are not related. 

 Haensch J has noticed that species of the genus Odontocera 

 resemble various Hymenoptera, one species being called 0. 

 braconoides; he also observed that these Hymenoptera - like 

 Longicorus, instead of withdrawing their underwings under the 

 elytra as beetles generally dn. vibrate them rapidly like Hyn;en- 

 "ptera. A large number of Loiigicnrn- ,-tridulate loudly by rubbing 

 a ridge inside the pronotum on a highly specialised, striate >urf;i<-e 

 at the base of the scutellum, and therefore covered up when the 

 Insect is contracted in repose. A few produce noise by rubbing 

 the hind femora against the edges of the elytra, somewhat after 

 the fashion, of grasshoppers. In this case there appears to be 

 comparatively little speciality of structure, the femora bearing, 

 however, more or less distinct small granules. The species of the 

 Hawaiian genus Plagithmysus produce sound in both these 

 manners, the thoracic stridulating organ being beautifully de- 



o o o */ 



velupcd, while in some species the margin of the elytra and 

 b:;se of the femora are also well adapted for the purpose of sound- 

 production, and in a few species of the genus there are al.- 

 highly-developed stridulating surfaces on the hind and middle 

 coxae. This is the only case in which a beetle is known to 

 possess more than one set of sound-organs in the imago state. 

 Three divisions of this family are distinguished, viz. 



1. Front coxae large and transverse ; prothorax with distinct side mar- 

 gins. Sub-fain. 1. PRIONIDES. 



2. Front coxae not greatly extended transversely, thorax not margined ; 

 last joint of maxillary palpus not pointed, usually broader (more or less) 

 than the preceding joint. Sub-fain. 2. CERAMBYCIDK-. 



3. Front coxae usually round and deeply embedded ; last joint of maxil- 

 lary palpus pointed ; front tibiae with a more or less distinct, slanting groove 

 "ii the inner side. Sub-fam. 3. LAMIIDES. 



The Prionides are on the average considerably larger in size 

 than the members of the other divisions, and they include some of 

 the largest of Insects. The Amazonian Titanus giganteus and the 

 Fijian Mn<'r<itn,na heros are amongst the most gigantic. Some 

 uf the Prionides have a great development of the mandibles in 

 the male sex analogous to that we have already noticed in 

 Lucanidae. The larvae of the large Prionides appear in various 

 parts of the world to have been a favourite food with native 

 1 Berlin, ent. Zeitsclo: xli. 1S96, SB. p. 22. 



