352 NATURAL HISTORY OF ARTHROPODS. 



fungi, upon dead animal and vegetable matter, upon dung, and upon plant-galls ; the 

 larvae of HypopMoBUS ferrugineus devour the larvae of Tomicus stenographus, and 

 the larvae of Triboliunt ferrugineum and of T. castaneum are museum pests. The 

 larvae as well as the images of the Tenebrionidae are usually abundantly parasited by 

 intestinal Gregarina ; of some species of Tenebrionidae one cannot find an individual, 

 upon dissection of large numbers, that does not harbor one or more species of these 

 parasites. 



The geographical distribution of the Tenebrionidae is somewhat remarkable. On 

 the eastern coast of North America the family is poorly represented, but the number 

 of genera and species in the fauna increases toward the west, until, upon reaching 

 California, they are among the most abundant Coleoptera. They are especially 

 abundant also along the western coast of South America, and in Europe. 



The uses to which Tenebrionida3 have been put are comparatively few. The larvae 

 of Blaps mortisaga are said to be roasted and eaten by Egyptian women, and the 

 larva? of Tenebrio and AlpJtitobius have been reared in zoological gardens as food for 

 amphibians and insectivorous birds. 



Among the beetles belonging to the sub-family Tenebrioninae are those of the genus 

 Helops. In Helops the tarsi are slender, the abdomen not pedunculate, and there is a 

 coriaceous band above the labrum ; some of the species are wingless, and their form 

 varies from oblong to oval. Some of the species of Helops are beautifully striped 

 longitudinally with changeable bronze lines. This is especially the case with H. micans, 

 found in the northeastern United States. The larva of If. striatus, a European species, 

 has been found living in decayed coniferous wood, feeding not only upon the wood 

 but upon the excrement of wood-boring longicorn larvae. II. pullus has been found in 

 Illinois about apple and peach trees that had been attacked by borers. 



jBolitotherus bifarcus is a curious rough beetle not uncommon in the northeastern 

 part of the United States and in Canada about species of Polyporus and other fungi 

 upon trunks of trees. It is from 0.4 to 0.5 of an inch long, and dull 

 brown, the lateral margins of the prothorax are flattened and extend 

 forward each side of the head ; two protuberances upon the dorsum 

 of the prothorax are short in females, but in males extend upward 

 and forward to form veritable horns, which are of variable length, are 

 flattened out from above and below, and are fringed with light brown 

 hairs around their margins. The antennae are short and ten-jointed. 

 The Iarva3 feed in holes which they burrow in fungi. They are about 

 Fl tkesblfu/rcus t . ~ 0.75 ^ an men l n ' when full grown, long and narrow, with the 

 abdomen ending in two spines. Pupation takes place within the 

 fungus. Eledona agaricola, a European species closely related to Bolitotherus, has 

 similar habits. 



Diaperis has a short, oval form, smooth surface, and the first joint of the hind tarsi 

 not exceeding the second in length. D. hydni is about 0.25 of an inch long, the elytra 

 are red spotted with black, the rest of the insect is black ; it is very common upon Poly- 

 porus betulinus, a large fungus that attacks dead white-birch trees, and in which the 

 larva of the beetle feeds. D. boleti, from Europe, is a trifle larger than D. hydni, and 

 has a broad, irregular black band across the middle, and a similar band near the apex 

 of the elytra; its habits are like those of D. hydni. Hoplocephala differs generically 

 from Diaperis in having the first joint of the posterior tarsi as long as the second and 

 third joints. If. bicornis, a smooth beetle, only about 0.15 of an inch long, and of a 



