May, 1920] Studies in Food of Spiders 251 



in the season gave one hundred and fifty-seven individuals. 

 This number will seem to be a little inconsistent with the number 

 given for a small area. The reason is that cattle and hogs were 

 pastured here. Where cattle were allowed to pasture the 

 spiders gradually left and moved to a field where they were 

 undisturbed. 



Observations were made along a public road for a distance 

 of sixty rods. The distance from the ditch along the side of 

 the road to the fence varied from two to three feet. This 

 space was overgrown with golden rod, blackberry bushes, 

 timothy and asters. In this distance three hundred and twenty- 

 two individuals were counted. The number was counted 

 several times, but remained fairly constant. It is seen that 

 these spiders are very abundant in a great variety of places. 

 The fact that they are of a large size and very abundant makes 

 them of some importance from the standpoint of their feeding 

 habits. The position of the web has a great deal to do with 

 the food eaten. Webs of Argiope riparia are placed in so 

 many situations that a great variety of insects is captured. 

 The vertical position of the web aids in capturing any kind of 

 insect that happens to be moving in its path. The spider 

 waits for its prey on the center of the hub and does not build 

 a retreat. When an insect becomes entangled in the web it 

 advances upon it, pulls out a swathing band and thrusts this 

 against the insect. The spider changes from one hind leg to 

 the other just as Argiope trifasciata does and so keeps the 

 insect at a safe distance. Sometimes the insect is pierced 

 with the chelicer^, but often this is not the case. The spider 

 merely wraps it up to await the time when it is needed as food. 

 Many insects were taken from webs and kept a day before the 

 swathing band was removed. Often the insect was alive when 

 the band was taken off which would not have been the case 

 had the spider pierced it with the chelicerae. The insect is 

 always wrapped so tightly that it cannot make any resistance 

 nor injure the web after it has once been enswathed. In case 

 the insect is too large the spider drops to the ground by means 

 of a dragline or else ascends to some leaf where it lies very 

 quiet until the danger is past, when it returns to its former 

 position on the hub of the web. This spider also makes barrier 

 webs similar to Argiope trifasciata. 



