Blattidae 



283 



Family 



BLATTIDAE 



CARE AND REARING OF BLATTELLA GERMANICA 



C. M. McCay and R. M. Melampy, Cornell University 

 Blatella germanka is a useful insect for physiological studies because 

 of its quick rate of growth, rapid reproduction, and 

 omnivorous feeding habits. An ordinary fish aquarium 

 or museum jar covered tightly with cheesecloth may be 

 used as a cage for a stock colony. Water may be supplied 

 by an ordinary baby chick waterer. Absorbent cotton 

 should be placed in the pan of the fountain as it prevents 

 drowning of the insects. A stock diet of ground whole 

 wheat 50',, dried skim milk 45%, and dried bakers' 

 yeast 5% is adequate for growth and reproduction. 



For experimental work with individual insects or 

 small groups, ordinary half-pint milk bottles may be 

 used as cages ( Fig. 63 ) . The milk cap is perforated with 

 numerous pin-holes to allow air to enter the container. 

 The water is supplied by a vial containing damp cotton 

 which is mounted on the cap by a cork. The diet to be 

 studied is placed in a small paper cup or similar container. 



COCKROACHES* 



Fig. 63. — 

 Rearing bot- 

 tle for Blat- 

 ella germanica. 



Cockroaches may be kept in wide-mouthed gallon 

 glass jars, each containing a layer of sawdust on the bottom and a 

 small pan of water. Over the top of each jar is stretched a piece of 

 cheesecloth, held in place by a rubber band. A thin line of vaseline 

 is placed around the inside shoulder of the jar, and the cockroaches do 

 not attempt to pass this line.** The jars are kept in a rather dark place 

 where the temperature averages 70 F. 



* Reprinted, with slight changes, from Turtox News 7:Xo. n, 1929, by John M. Kelley, 

 General Biological Supply House. 



** Editor's Note: J. Franklin Yeager, of Iowa State College, has described to us the 

 cage he uses for keeping large numbers of Periplaneta. It consists of a wooden framework 

 on legs, with a bottom of pressed board, sides of glass below for observation and copper 

 wire above for ventilation, and a top of pressed board with a hinged door for easy access. 

 The legs supporting the cage are set in cups of water to keep out ants. 



A covered hole in the bottom with a metal shaft leading downward serves for removal 

 of numbers of the roaches. They are swept down this shaft into a beaker edged at the 

 top with vaseline. A rim of vaseline is also kept around the top of the glass portion of 

 the sides of the cage. 



"Ootheca dropped by the females may be removed to other containers for hatching 

 purposes. When the cage is kept clean of ootheca, molted exoskeletons, and dead in- 

 dividuals, it is suitable for retaining large numbers of roaches over considerable periods of 

 time. The cage may also be used with certain other species of insects." J. G. N. 



