EQUIPMENT FOR KEARTNC BEETLES. 



15 



Saiigus, Mass. The average size was S feet (5 inches J)y 1 1 feet 4 

 inches, with 8-foot posts. The roof was covered with canvas, and a 

 strip of this material was attaclied to the sills and extended into the 

 ground to ])revent the escape of the insects. It was f(Hind tliat these 

 cages were too large for the i)urpose of securing detailed data con- 

 cerning reproduction and the exact amount of food consumed, and 

 the follo^\^ng year they were used only in a limited way. 



EQUIPMENT USED FOR REARING PREDACEOUS BEETLES. 



Following out the methods used by the writer in 1896-97, when 

 investigating the life history of some of our native species of this 

 genus, an attemj)t was made to keep this sj)ecies under observation 



Fig. 6. — Jars for rearing Calosoma beetles: a, Large jar with MOndeii top and "ladder"; b, small 

 jar with wooden top; c, showing construction of top and "ladder"; d. jar with ehecsecloth top 

 held in position with rubber band. (Original.) 



in glass jars partly fdled with earth. The best results were secured 

 by using glass battery jars, which can be obtained from most dealere 

 in glass supphes. The size of the jars selected should be governed 

 by the size of the species to be studied. The best results ^^dth syco- 

 flianta were secured by using jars 8^ inches tall and 6J- inches in 

 diameter, or 7\ inches tall and 5J inches in diameter, all outside 

 measurements. After the fu'st season a wooden cover was used 

 instead of the usual cheesecloth top. (See fig, 6.) One-inch boards, 

 an inch larger in diameter than the top of the jars, were used for the 

 pur])ose. These had a 2-inch hole bored in the center which was 

 covered with wire netting. A groove cut near the outer edge of the 

 cover allowed it to fit loosely on the jar. In rearing beetles it has 

 been found of advantaw to extend the wire wliich covers the hole in 



