80 THE HOUSE FLY DISEASE CARRIER 



"Several of the orb-weaving spiders are often found 

 on porches, where their snares will intercept many 

 flies. Epcira scricata nearly always occurs near or on 

 buildings." 



FALSE SCORPIONS ON FLIES 

 ^ 



There is a group of Arachnids, known as the false 

 scorpions or pseudoscorpions, which are much smaller 

 and simpler in structure than the true scorpions. They 

 have no poison gland and no spine at the end of the 

 body. They bear much the same relation to the true 

 scorpions that the mites do to the true spiders. They live 

 beneath the bark of trees, in moss, between the leaves 

 of old books, etc. They run sidewise and backwards, 

 and live on mites and small insects. Two or three 

 species of the false scorpions are sometimes found 

 clinging by their claw-like pedipalps to the legs of the 

 house fly and other kinds of flies. It is not known 

 why they attach themselves to these insects, but it is 

 hardly probable that they feed on them, and it seems 

 altogether likely that they simply attach themselves in 

 the same way as does the hypopus of the Tyroglyphid 

 mite, in order to be carried to some better feeding 

 ground. Much has been written upon this subject, 

 and many different views are held about this attach- 

 ment, but there is no sound evidence on the one side 

 or on the other. The suggestion has been made that 

 the false scorpion seizes the legs of the flies without 

 realizing their size, and that they remain attached until 

 the fly dies and then they feed upon the body. Doctor 



