82 A BOOK OF INSECTS 



The Bruchkkc, represented by our bean and pea 

 beetles (Bruchus riijimanus and B. pisi), make up a 

 small family whose larvae feed in seeds, chiefly those of 

 leguminous plants. The female beetle lays her egg on 

 the flower or the seed vessel, and the newly-hatched larva 

 burrows through the pod and enters a developing seed, 

 where it completes its metamorphosis. 



The leaf-beetles (Chrysoj/ielidce) are closely allied to 

 the long-horns, but they have shorter antennae ; while 

 their oval, convex form, though unimportant from a scien- 

 tific standpoint, is often a useful popular distinction. 

 Many of the species are brightly coloured and brilliantly 

 metallic. The larva? have hard heads and well-developed 

 thoracic legs. They and the adult beetles feed upon 

 leaves, and often cause great damage to field and garden 

 crops. One species — the Colorado beetle (Do?'yphora de- 

 cemlineata) — is well known on account of its injuries to 

 potato crops in North America. The pretty little aspa- 

 ragus beetle (Crioceiis asparagi) is another member of 

 this family, which also includes the curious tortoise-beetles 

 (Cassida). The latter frequent thistles, wild mint, and 

 other plants, and look more like scale insects than beetles. 



We now come to a group of beetle families which are 

 often spoken of collectively as the sub-order Heteromera. 

 In all the species the tarsi of the front and middle legs are 

 five-jointed, while those of the hind-legs are four-jointed. 

 The family Tenebrioiiidce includes the cellar beetle (Slaps 

 mucronata), which shares with the cockroach the popular 

 name of " black beetle." Another member of the same 

 family is the well-known mealworm — the larva of Tene- 

 brio molitor. The family llhipiphoridce is represented in 

 Britain by the curious Metoecus jxiradomis, the larva of 

 which feeds as a parasite upon wasp grubs. The family 

 31eloidce includes the well-known oil beetles of the genus 



