TRACHEATA 



359 



mesostemal cavity, it causes the beetle, if lying on its back, 

 to be projected into the air, whence it usually falls on its feet. 

 The larvae are known as " wire-worms," and are very destruc- 



FiG. 202. — Elater Uneatus, the "skip-jack" 

 Tjeetle, with its larva the "wire- worm.'' 

 One of the larvae is enlarged to show the 

 markings on the terminal segment. 



tive, feeding on the roots of grasses and other plants. They 

 are long cylindrical grubs generally of a reddish-brown hue, 

 and are extremely tough and tenacious of life. Elater Uneatus 

 is the common skip-jack beetle. 



Sub-order 2. Heteromera. 



Family Tenebkionidae. — An ill-defined family, with many 

 mimetic forms. The elytra are rounded at their ends and cover 

 the abdomen, the hind wings are frequently wanting. The 

 larvae are linear, flattened, and horny, and resemble wire- 

 worms. Many of these beetles shun the light and are sombre 

 in colour, some have an unpleasant smell, and others are covered 

 with a powdery secretion. The larva of Tenebrio molitor is 

 known as the meal-worm. 



Family Meloidae. — The head is bent forward, the legs 

 are long, and the bodies are elongated and soft. The beetles 

 are frequently found on flowers. The larvae are parasitic. 

 The larvae of Meloe attach themselves to the bodies of various 

 species of bee ; they are thus conveyed into the hives, where 

 they feed upon the food provided for the larvae of the bees. 

 The larvae pass through a metamorphosis which is more com- 

 plicated than is usual in insects, this is termed hypermeta- 

 morphosis. Lytta vesicatoria, the Spanish fly, is used as a 

 vesicant. 



