TRACHEATA 359 
mesosternal 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- 
op Fie. 202.—Elater lineatus, the “ skip-jack ” 
beetle, 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. later lineatus 
is the common skip-jack beetle. 
Sub-order 2. Heteromera. 
Family TENEBRIONIDAE.—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 Yenebrio molitor is 
known as the meal-worm. 
Family Metomart.—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. 
