LARVAL HABITS OF THE TIGER BEETLES. 159 



Arhoreal Forms. 



There are several genera of tree dwellers. Their young stages are 

 unknown except in Collyris. R. Shelford has recently described one of 

 these in detail. The larva has its burrow in the stems of the coffee plant 

 and is an agricultural pest in the East Indies. Its method of food-taking is 

 like that of the larvae of Cicindela. 



III. Methods of rearing Larv^. 



Cicindelidce have always been regarded as very difficult to rear. I have 

 had no success outside of a well ventilated glass-roofed vivarium. The adults 

 of a given species were put in a cage containing the soil which they frequent, 

 or better, that which their larvse inhabit. Most of the species here considered 

 can be induced to lay without difficulty. 



For rearing larva? in large numbers from the last stage to maturity, a 

 screen bottomed box containing sand (or sandy soil) can be placed over other 

 moist soil which will maintain any desired degree of moisture. If well cared 

 for, even the species that leave their holes when conditions are not favourable, 

 can be reared in numbers by this method without great mortality. It is well 

 to tack strips of tin on the edge of such a box, allowing them to project 3 to 

 5 cm. over the inside ; this will prevent the larvse from escaping. 



For the study of larval habits, cages were made of glass plates separated 

 by glass tubing of a diameter corresponding to the width of the prothorax of 

 the species to be studied, and cemented together with paraffin of a high 

 melting-point. Bottoms were made of cloth saturated with paraffin (by first 

 wetting in xylol or turpentine) to prevent decay, and fastened in place with 

 hard paraffin. Straight cylindrical Welsbach lamp chimneys w^ere also used 

 for this purpose. The soil, if well packed, will stay in these and the 

 moisture may be maintained by capillarity, through additions from below. 



Pupse were often kept in Syracuse watch-glasses lined with moist filter- 

 paper, through the greater part of the pupal life, with a relatively low 

 mortality. The filter-paper should be moistened with 3 per cent, hydrogen 

 peroxide from time to time ; this may be dropped directly on the bodies of 

 the pupse and will help to keep down the fungi which are the chief cause of 

 trouble in all these studies. 



All larvse and adults were fed with small pieces of lean meat which were 

 placed in the burrows or cages every day. 



IV. Life-Histories of the Species occurring near Chicago. 



Twelve races have been studied ; all but one have been reared to at least 

 the second larval stage. Extensive field observations connected with the 

 collecting and rearing of three to four thousand individuals from the last 



