350 



HOUSEHOLD INSECTS 



of legs (Fig. 119). In this stage the mites are active and 

 readily crawl about in search of something to devour. 

 They are predaceous, as we have already mentioned, and 

 live upon the larvse of the wheat joint worm, Angoumois 

 grain moth, wasps, and other insects. When a female 

 mite finds a larva, it punctures the skin and begins to suck 

 the juices. In a day or two the posterior segments of the 

 abdomen begin to enlarge and continue to do so until 



they become fifteen or twenty 

 times as large as the anterior 

 part of the body. In this 

 condition the females do not 

 move (Fig. 120). 



Within the enlarged ab- 

 domen, the eggs are continu- 

 ally forming and developing 

 the young mites. The young 

 mites do not leave the body of 

 the mother, but pass through 

 all of their changes and actu- 

 ally become mature before they 

 pass out of the body. The 

 females are prolific. The 

 number of young produced by a single female varies from 

 a few to nearly 300. 



Methods of control. — In households, the remedy is 

 perfectly obvious. Since the mites are found in straw 

 contained in mattresses, ticks, or in straw placed beneath 

 carpets, they can be exterminated by removing the mat- 

 tresses, ticks, and straw. The mattresses could be placed 

 in storage in some outbuilding and if left there long enough 

 would finally become free of the mites, for the latter would 



Fig. 120. — The female mite 

 when full of eggs, enlarged. 



