BEETLES. 345 



Attelabus rhois, a reddish pubescent weevil, quite robust, and about 0.2 of an inch 

 long, with short proboscis, is quite common on the hazel {Corylus) in the northeastern 

 United States. The species of Attelahcs roll up the edges of the 

 leaves of their food plant to form a protecting cell for their eggs 

 and larvae. 



The weevils belonging to the sub-family Rhynchitin£e differ 

 from the Attelabinse in having flat mandibles, which are toothed 

 on both outer and inner edges. 



Mhynchites bicolor is about 0.2 of an. inch long, and is shining 

 black and red. In New England specimens the elytra, prothorax 

 above, and head as far as the eyes, are red. Specimens from other 

 localities vary in the distribution of the red, but the prothorax 

 above and the elytra are always red. This species is abundant _ 



throughout the United States, on wild roses. imgicoiUs. 



Sub-Oedek III. — Heteromera. 



The Heteromera have the anterior and middle tarsi five-jointed, while the posterior 

 tarsi have only four joints. Besides some anomalous families containing but few 

 species, this group of beetles includes the Meloidte, Stylopidte, Mordellidse, Anthicidae, 

 and Tenebrionidse. 



The Meloid^, oil-beetles or blister-beetles, have been used in oriental medicine as 

 early as history gives any account of the mode of treating diseases, but, however 

 curious medical properties they have, they are, to the naturalist, still more curious on 

 account of iheir remarkable life history, and the strange modifications which parasitism 

 has produced in the larval stages of many of them. The beetles themselves are gener- 

 ally of medium or large size ; the vertical head is abruptly narrowed behind into a neck, 

 and is not set into the prothorax; the antennae are generally eleven-jointed, and not 

 long ; the thorax has no lateral suture, and is narrower than the elytra ; the hind coxae 

 are large and prominent ; the coxal cavities are open behind ; the claws are cleft or 

 toothed ; the elytra are sometimes small, and overlap each other at the suture, 

 although they often fail to cover the abdomen. 



Species of Meloe exude a yellow fluid from the knee-joints when disturbed. This 

 fluid is of a disagreeable odor, and contains, according to P. Magretti, uric acid. 

 Leydig states that, as in the similar fluid from Coccinellidae, this is onlj- the blood of 

 the insect. Among the curiosities of the anatomy of Meloidae, may be mentioned 

 the eyeless genus Meloetyphlus, from Peru, and the proboscis which is present in some 

 species of Nemognatha. Dr. Hermann Mtiller has described the proboscis of one 

 South American Nemognatha which is as long as the insect itself, and is made up of 

 the two maxillaB hollowed out on their insides and pressed together laterally, forming 

 a tube for sucking honey, exactly as is the case with the proboscis of the Lepidoptera. 



The blistering properties of cantharides, which gives them their value as a 

 medicine, is due to the presence in all parts of the insect of a substance called can- 

 tharidin. Ordinarily, cantharides are used for making blister-plasters in the form of a 

 powder, made by simply grinding the dried beetles, but as the cantharides, both before 

 and after grinding, gradually lose their strength, on account of the action of other 

 substances in them upon their cantharidin, and as they are. likewise subject to destruc- 

 tion by museum-pests (Anthreiius) and by other insects, it is better to extract the 



