COLEOPTERA 219 



Sub-order V. — Heteromera (heteromerous beetles) 



Fore and middle legs with five-jointed tarsus, hind legs with 

 four-jointed tarsus. 



Family Tenebrionidse (darkling beetles). Mostly dark- 

 coloured, often ground-dwellers, with soldered elytra. 



The meal-worm {Tenebrio molitor) is a well-known pest in 

 mills and granaries ; it is long, narrow, and rust-coloured, with 

 small head, and pointed behind ; there are three pairs of rather 

 short thoracic legs and two minute appendages on the last 

 segment. These larvae are bred by bird-fanciers as food for 

 captive birds. 



Family Cantharidse (oil-beetles). In the only common 

 British species the adult is incapable of flight and the wing- 

 covers do not meet. The blister-beetles of pharmacy belong 

 to this family. 



Sub-order VI. — Phjrtopliaga (leaf-eating beetles) 



All the tarsi apparently four-jointed. 



Family Oerambycidse (longicorns). Body often elongate 

 and parallel-sided, wing-covers marked by a regular pattern of 

 fine hairs. Antennae long. 



Family Chrysomelidse (leaf-beetles). Antennae often long. 

 Elytra usually polished. Less elongate and smaller, as a rule, 

 than Cerambycidae. 



The mustard-beetle or black-jack {Phmdon armoracim) is a 

 broadly oval small beetle 3-3.5 mm., of metallic blue or green 

 and black colour. The elytra are marked with rows of minute 

 punctures. The larvse are black-headed, warty, rather hairy, 

 and feed in numbers together on the leaves. They pupate in 

 the earth, and emerge as beetles about a fortnight later. 

 There is more than one brood in the season. During winter 

 they shelter in crevices, or among reeds. This beetle attacks 

 rape, kohl rabi, and other Cruciferse, as well as mustard. 

 Mustard is liable to be injured by the turnip-flea, the turnip 

 blossom-beetle {Meligethes) arid weevils {Ceutorhynchus), as 

 well as by the proper mustard-beetle. 



The asparagus-beetle (0/o«m aspargi) is elongate, blue- 

 black, with red thorax bearing two spots, elytra yellowish, with 

 dark bands, longitudinal and transverse, forming a' kind of 



