LARVAL HABITS OF THE TIQER BEETLES. 165 



was unable to get any until September 5tli, at which time they were very 

 much scattered. The specimens reared from larvae brought into the vivarium 

 emerged as in former years. These insects are unable to dig their way out 

 until the soil is thoroughly wet. Leng has observed a similar variation in the 

 time of appearance of another variety. 



CiCINDELA FORMOSA, Subsp. GENEROSA. 



This species lays its eggs in May and June, in fresh sand. Eggs are 

 difficult to secure and have not been studied. In my cages larvse appeared 

 June 24th. The head and prothorax are much larger than those of any of 

 the other species here considered and possess a colour pattern (PI. 24. fig. 16). 

 The burrow is entirely different from those described above. 



1 he Burrow. — The main part of the burrow is from 30 to 50 cm. deep 

 and vertical throughout the greater part of its course. At a distance from the 

 opening equal to two-thirds of the length of the animal's body (PI. 25. 

 figs. 22-24), it curves sharply to a horizontal position like a stove-pipe elbow 

 and opens into the side of a pit. The edge of the pit usually overhangs the 

 mouth of the burrow in such a manner as to make it almost invisible. The 

 head and prothorax of a larva of the first stage are almost as large as those of 

 the last stage of some other species (1'75 ram.). The larvse are always to be 

 found in sand that is slightly shifting. The great size of the hole would cause 

 it to fill up with the sand moved about by the wind and thus make the animal 

 a great amount of labour. Each larva cements the sand-grains slightly with 

 saliva. Accordingly its hole and pit near the opening are quite firm and the 

 wind does not ordinarily disturb them. The pit may fill and be almost 

 obliterated by the action of either wind or rain ; the burrow, however, remains 

 undisturbed, except possibly when the rain is very heavy. This type of 

 burrow possesses advantages in securing prey ; the pit acts as a pitfall for 

 small animals. It is more elaborate than that of C. liyhrida (a European 

 species), described by Lesne, in which the pit and curvature of the burrow 

 are i-elatively imperfect (PI. 24. fig. 17). 



In my cages, the larvas reached the third stage in the latter part of August. 

 They all disappear in the field by the first of October and reappear again in 

 the spring. In the latter part of June and the first half of July, they go into 

 the prepupal stage, each in an oblique side cavity about 10 cm. below the 

 surface (PI. 25. fig. 24) : the upper part and much of the lower part of the hole 

 is filled with the sand that is taken from this elliptical cavity. The adults of a 

 given generation are not found so abundantly in the fall and summer as in 

 the spring, and it is probable that many remain over winter in the pupal 

 cavities. Those that come to the surface in autumn go into hibernation 

 somewhat earlier than some of the other species and come out somewhat later. 

 They appear in the latter part of April or early May, reach sexual maturity in 

 about a month, lay eggs and die. 



LINN. JOURN. ZOOLOGY, VOL. XXX. 13 



