364 



NATURAL HISTORY OF ARTHROPODS. 



FIG. 417. Euchroma gigantea. 



The family of BUPRESTIDJE includes a large number of beetles which somewhat 

 resemble the Elateridae, but differ from them in not possessing the power of springing 



when placed upon the back, and consequently 

 they do not have the prothorax very freely mov- 

 able upon the mesothorax. They also differ from 

 the Elateridae in having the first and second ven- 

 tral segments connate. The eleven-jointed an- 

 tennae of the Buprestidae are almost invariably 

 serrate ; the head is small and retractile to the 

 eyes in the prothorax ; the posterior end of the 

 body is tapered off to a point ; the ornamentation 

 is usually with metallic colors, and the surface is 

 often highly polished. In Polybothris^ a genus 

 found in Madagascar, the coloration during life 

 is glistening metallic, which, as in Cassida of the 

 Chrysomelidae, disappears upon the death of the 

 insect. The tropical species of Biiprestidae are 

 often large, Euchroma gigantea from Brazil 

 reaching a length of 2.75 inches, and a breadth 

 of over an inch ; the size of the species becomes 

 gradually less in approaching the temperate and 

 colder regions. These insects frequent flowers or sit upon bark, and are most active 

 in bright sunlight ; upon approach, many kinds fly away with great rapidity, others 

 retract their short legs and drop to the ground, feigning death. 



The larvae of Buprestidae usually bore elliptical passages in living and dead wood ; 

 a few, like those of Trachys, mine in leaves, and still fewer (e. g. Diphucrania 

 auriflua) live in galls. The larvae have a very characteristic form due to excessive 

 enlargement and partial chitinization of the prothoracic segment, into which the head 

 is retractile. There are no ocelli and no feet, the latter organs being represented in a 

 few species by little fleshy tubercles ; the antennae are very short and formed of two 

 or three joints. Larval life varies in duration ; in Trachys mimita, which mines wil- 

 low leaves, Rudow found two generations yearly; Perris found that many species 

 completed their metamorphoses in a year, while Ratzeburg states that 

 two years are occupied in the cycle of metamorphoses. Pupation 

 takes place in the burrows made by the larva. 



The small, flattened, ovate, somewhat angular species of Brachys 

 are found upon leaves of different plants, and their larva? are leaf- 

 miners, like those of the related genus, Trachys. B. tessellata is only 

 about 0.15 of an inch long, and nearly black in coloration ; it is found 

 in the eastern United States. J3. ceruginosa, a species of about the 

 same size, and found in the same region, mines in the leaves of the 

 beech. 



The numerous species of Agrilus are elongated, and have the antennae free, not 

 received in grooves as in Brachys and Trachys. Agrilus ruficollis is quite injurious 

 to raspberry and blackberry patches in the eastern United States. The beetle is 

 narrow, about 0.25 of an inch long ; its head and thorax is a beautiful coppery bronze, 

 the elytra are black. The larvae, which are about 0.5 of an inch long, and pale yellow, 

 with a brownish head and black mandibles, bore about in the sap-wood of the black- 



FIG. 418. Brachijs 

 tessellata. 



