330 



NATURAL HISTORY OF ARTHROPODS. 



Differing from the foregoing genera in having simple mandibles without fringes is 

 the genus Desmocerus. D. palliatua is found about elder {Sambucus) when it is in 

 blossom. This beetle is about 0.8 of an inch long, of a deeij 

 Prussian-blue color, except the anterior portion of the elytra, which 

 is orange yellow. It is one of the most brilliant of our longicorn 

 Coleoptera. Its larva bores in the pith of the elder. The females 

 of J), auripennis, a species found on the Pacific coast, are dimor- 

 phic, the two forms being distinguished by diffei-ent size of mark- 

 ings and by different fineness of punctation. 



Passing now to genera of the sub-family Cerambycinse that 

 YiG.3&a.— Desmocerus have the base of the antennne partly surrounded bv the eyes, 



palliatus. . .' 



Clytus and related genera have long legs, finely granulated eyes, 

 a rounded or broadly triangular scutellum, tibiae not carinated 

 and with large spurs, prothorax never spiny or tuberculated, 

 elytra not sinuate, and intercoxal process acute. The species 

 are generally banded with yellow, white, or black, and are 

 active both at flight and in running. Clytics in its limited 

 sense, as defined by Drs. Le Conte and Horn, is confined in 

 North America to two species, of which the life histories are 

 unknown. Clytui wietis, a common yellow, black, and red 

 European species which is figured on page 328, is found in its 

 larval state in the dead wood of mulberry and sycamore trees, 

 and in the ■ living Avood of some other trees. V. sexguttatus, 

 also figured, is from Algiers. 



Cyllene differs from Clytus in having the head proportionally 

 smaller, the front short, the intercoxal process rounded, and the 

 pronotum hollowed out at the sides of its base. Cyllene roliniw 

 is very abundant upon locust trees, the wood of which is seri- 

 ously damaged by its larvse. The beetle is brownish black, figured beneath and trans- 

 versely striped above with yellow, and has reddish legs. Almost all the figuration is 

 produced by a coating of hair-like scales, the beetle being mostly black 

 when these scales are removed. This beetle is quite common in autumn 

 upon the blossoms of golden-rod {Solidago), the pollen of which it eats. 

 In September the beetles may be seen, often in considerable number, 

 running over the bark on the trunks of locust trees, cop)ulating and 

 ovipositing. The eggs are white, and are laid in crevices of the bark, 

 five or six in a place. They hatch in a short time and the young- larvae 

 eat a slight distance beneath the bark before winter comes on. The next 

 spring they burrow about in the wood, throwing their refuse out of holes which thej^ 

 linve made in the bark. Pupation takes place the latter part of July, and the beetles 

 emerge in August and September ; the entire metamorphosis of this species thus lasts 

 only one year. Cyllene pictus is so nearly like C. robinice that it has been confounded 

 with it, oftentimes by good observers. C. pictus lives as larva, however, in hickory 

 (Carya), the imago appears in June, and it has slenderer and shorter antennae than 

 are those of C. robinice. 



Plagionotus speciosus has a form and style of marking similar to C. robinice, but 

 is larger and does not have the pronotum hollowed out at the sides. Its colors are 

 deep black, and yellow. The beetle is found in July, when it lays its eggs in the 



Fig. 366, — Clytus sex- 

 guttatus. 



Pie. 



Jene robinice. 



