COLEOPTERA 



i35 



that their legs are six-jointed except in a single exotic species; this is 

 one more segment than is found in the legs of other beetle larvae. The 

 legs are usually furnished with two claws, whereas the legs of other coleop- 

 terous larvas are one-clawed. 



This suborder is represented in North America by less than ten fam- 

 ilies. 



Family Cicindelid^; 



The Tiger-beetles 



The graceful forms and beautiful colors of the greater number of the 

 tiger-beetles, those of the genus Cicindela, have made the family one of 

 the favorites of students of Coleoptera. Their popular name is suggestive 

 of their predacious habits, and of the stripes with which many are 

 marked. They are usually a metallic green or bronze, banded or spotted 

 with yellow. Some are black; and some that live on white sand are 

 grayish-white, being exactly like 

 the sand in color. Figure 220 

 represents a common species of 

 Cicindela. 



A useful character for distin- 

 guishing the members of this 

 family is the fact that the terminal 

 hook of the maxilla (the digitus) 

 is united to this organ by a mov- 

 able joint (Fig. 221, h). FlG ' 22a FlG - 22T - FlG ' 222 " 



The tiger-beetle larvas (Fig. 222) are as ugly and ungraceful as the 

 adults are beautiful. The two have only one habit in common — their 

 eagerness for prey. The larvae live in vertical burrows in sandy places or 

 in beaten paths. These burrows occur also in ploughed fields that have 

 become dry and hard. They often extend a foot or more in depth. The 

 larva takes a position of watchfulness at the mouth of its burrow. Its 

 dirt-colored head is bent at right angles to its lighter-colored body and 

 makes a neat plug to the opening of the hole. Its rapacious jaws extend 

 upward, wide open, ready to seize the first unwary insect that walks 

 over this living trap, or near it; for a larva will throw its body forward 

 some distance in order to seize its prey. On the fifth segment of the 

 abdomen there is a hump, and on this hump are two hooks curved for- 

 ward. This is an arrangement by which the little rascal can hold back 

 and keep from being jerked out of its hole when it gets some large insect 

 by the leg, and by which it can drag its struggling prey down into its 

 lair, where it may eat it at leisure. It is interesting to thrust a straw 

 down into one of these burrows, and then dig it out with a trowel. The 

 chances are that you will find the indignant inhabitant at the remote end 

 of the burrow, chewing savagely at the end of the intruding straw. 



One hundred and fourteen species of tiger-beetles are now listed in 

 our fauna; these represent four genera, the principal one of which is the 

 genus Cicindela containing at least 76 species and many varieties. 



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 



