478 AN INTRODUCTION TO ENTOMOLOGY 



B. Sides of the elytra widely inflexed ; thorax scarcely margined. Amblycheila 

 BB. Sides of the elytra narrowly inflexed; thorax distinctly margined. ..Omus 



Cicindela. — To this genus belong the greater number of our tiger- 

 beetles; seventy-six species and many varieties occur in our fauna; 

 excepting the two species of Teiracha, all of the tiger-beetles found in 

 the East belong to the genus Cicindela. 



The members of this genus, unlike most other members of the 

 family, are diurnal in habit. They are found on bright, hot days in 

 dusty roads, in beaten paths, and on the shores of streams. They are 

 the most agile of all beetles; and they are not merely swift of foot, 

 but are also able to fly well. When approached, they remain still 

 until we can see them well but are still out of reach ; then like a flash 

 they fly up and away, alighting several rods ahead of us. Before 

 alighting they usually turn so that they face us, and can thus watch 

 our movements. They hide by night and in cloudy or rainy weather 

 in holes in the ground or beneath stones or rubbish. The beetles 

 have been found hibernating, each in a separate burrow extending 

 under a stone. I have seen them in September digging burrows in a 

 hillside; these descended slightly and were about five inches deep. 

 The beetles kicked the dirt out behind them as they dug, so that it 

 lay in a heap at the opening of the hole. 



Tetracha. — Two species of this genus are widely 

 distributed in the United vStates. They are rather 

 large, metallic-green beetles. Figure 557 represents 

 Tetracha Carolina, which can be distinguished by the 

 apical portion of the elytra being yellow. Our only 

 other species is Tetracha virghiica. These beetles are 

 nocturnal, hiding dttring the day and hunting by 

 night. 



Amblycheila. — The best-known representative 



of this genus is Amblycheila cylindrifdrmis , which is 



ig-557- found in Kansas, Colorado, Arizona, and New 



Mexico. It is a very large species, measuring 3 5 mm. 



in length. It is nocturnal, hiding in holes during the day and coming 



forth at night to capture its prey. Two other species of this genus 



have been described from Arizona and Utah. 



Omus. — Thirty-three species of this genus have been found on the 

 Pacific Coast, nearly all of them in California. They are nocturnal 

 insects, hiding under rubbish during the da}'time. 



Family CARABID^ 



The Ground-Beetles 



The ground-beetles are so called because they are very common 

 on the surface of the ground, lurking under stones or rabbish, where 

 they hide by day. At night they roam aboixt in search of their prey. 

 Our more common species are easily recognized by their shining black 

 color and long legs. On the Pacific Coast, however, the darkling 

 beetles (Family TenebrionidaO , which are also black and have long 

 legs, abound under stones and fragments of wood on the ground. 



