COLEOPTERA 



i47 



More than two hundred species of blister-beetles have been found in 

 this country. Our most common species in the East belong to the genus 

 Epicauta. These insects feed in the adult state on the leaves of various 

 plants, but especially those of potato, and upon the pollen of goldenrod; 

 the larvae, so far as is known, are parasitic in the egg-pods of 

 locusts. In addition to Epicauta vittata, discussed above, our 

 more common species are the Pennsylvania blister-beetle, 

 Epicauta pennsylvdnica, which is of a uniform black color 

 (Fig. 247); and Epicauta cinerea, which is sometimes clothed 

 throughout with an ash-colored pubescence, and sometimes 

 the wing-covers are black, except a narrow gray margin; 

 the two varieties were formerly considered distinct species; 

 the first is commonly known as the gray blister-beetle, the 

 last as the margined blister-beetle. 



The beetles of the genus Melee present an exception to 

 the characters of the Coleoptera in that the wing-covers, 

 instead of meeting in a straight line down the back, overlap 

 at the base (Fig. 248). These wing-covers are short, and 

 the hind wings are lacking. These beetles are called oil- 

 beetles in England, on account of the yellowish liquid 

 which oozes from their joints when they are handled. 

 Our most common species is the buttercup oil-beetle, 

 Melos angusticollis . It is found in meadows and pastures 

 feeding on the leaves of various species of buttercups. 



Fig. 247. 



Fig. 248. 



Fig. 249. 



Family Elaterid^e 

 The Click-beetles or Elaters 



There is hardly a country child that has not been entertained by the 

 acrobatic performances of the long, tidy-appearing beetles called snap- 

 ping-bugs, click-beetles, or skip-jacks (Fig. 249). Touch one of \/^ 

 them and it at once curls up its legs, and drops as if shot; it 

 usually lands on its back, and lies there for a time as if dead. 

 Suddenly there is a click, and the insect pops up into the air 

 several inches. If it comes down on its back, it tries again and 

 again until it succeeds in striking on its feet, and then it 

 runs off. 



Our common species of click-beetles are mostly small or of medium 

 size, ranging from -fa to f of an inch in length. A few species are 



> — m- , <*■ larger, some reaching the length of nearly 2 inches. The 



^jr' \(^/ majority of the species are of a uniform brownish color; 

 /8k Hv s< line are bl ac k " r grayish, and some are conspicuously 



^^ >/liJ\V s P°tted (Fig. 250). The body is elongated, somewhat flat- 

 / /^Byy tened, and tapers more or less toward each end; the 

 antennae are moderately elongated and more or less ser- 

 rate; the first and second abdominal segments are not 

 grown together on the ventral side ; and the hind coxae are 

 each furnished with a groove for the reception of the femur. 

 Adult elaters are found on leaves and flowers, and are exclusively 

 phytophagous; the larvae live in various situations; most of them are 

 phytophagous, but some species are carnivorous. 



Fig. 250. — A click- 

 beetle, Aeolus dorsalis, 

 natural size and en- 

 larged. 



