82 



ZOOLOGY 



The genus Theridium and its allied genera constitute the 

 most extensive family found in the United States. The 

 spiders belonging to the family are small, with relatively 

 large, rounded abdomens. They have eight eyes, arranged 

 in the manner shown in the diagram, Fig. 80. Their webs 



show no attempt at 

 geometric arrangement, 

 such as is seen in the 

 web of Argiope and 

 other orb-weavers, but 

 the threads cross in 

 every direction, forming 

 a sort of intricate trestle- 

 work. The species 

 Theridium tepidariorum 

 is the common little 

 cobweb-spinner of our 

 houses and barns ; it also 

 spins about fences. Its 

 color varies from a livid 

 white to a livid brown 

 or plumbeous color. In 



the south this species 



FHJ. 79. Argiope spinning the "winding . 



stair." The numbers 1, 2, 3, 4, indicate IS much preyed upon 

 points successively formed in the order of 

 these numerals. From McCook. 



^ y mud-daubing wasps 

 J P 



(Sphex J ), which put 

 twenty to thirty of them in each cell of the nest as 

 food for the young. Probably this enemy is one of the 

 causes that has driven this species to the homes of man. 



Food. Both Argiope and Theridium feed upon insects. 

 Flies, bees, grasshoppers, etc., are caught in the web and 



1 <r<t>if]Z, wasp. 



