376 BIOLOGY OF THE LABORATORY MOUSE 



Myocoptes musculinus koch. — This Acarina has been reported as fre- 

 quently found on mice, each mite tightly clutching a single hair at its base. 

 In this species it is the last two pair of legs that are modified for hair clasping. 



Fig. 151. — Myobia musculi, adult, dorsal view. 



Ewing (14) notes that after the infested mice are dead these mites will crawl 

 to the tips of the hairs where they are observed as tiny white specks. 



Control Measures for Other Insect Pests of the L.\boratory 



Cockroaches. — One of the most effective ways of eradicating cockroaches 

 is by the use of sodium fluoride. The dry powder should be dusted into 

 cracks of the partitions, behind baseboards, around sinks, under drain- 

 boards, and around the pipes and other such places frequented by the 

 insects. The roaches get the powder on their appendages and when cleaning 

 them get it into their mouths, thus becoming poisoned. This treatment is 



