220 The Ohio Journal of Science [Vol. XX, No. 7, 



Another example that might be given is an observation 

 made near a stump. The area was about 10 feet square. 

 One of the Attidas, Phidippus audax, was stalking a grass- 

 hopper. The non-net building species were further represented 

 by Castianeira descripta and Lycosa avida. An Argiope riparia 

 had a web at the edge of the stump on a raspberry bush. Epeira 

 trivitatta had its web on the same stalk and on a brush pile 

 beside the stump were the webs of seven Agelena naevia. 



The manner of capturing the prey is also of importance. 

 If a spider builds a vertical web of considerable size and places 

 it in weeds or grass it is evident that a great many more insects 

 will be destroyed than if the spider built a horizontal web 

 close to the ground or built no web at all. If the web is fiat 

 and horizontal, like those of the Agelenidae, the class of insects 

 will be more restricted than in the case of the large Orb Weavers. 

 The location of the web of Argiope riparia accounts for the 

 great diversity of the insects captured. A spider which captures 

 its prey by jumping on to it from the rear is not likely to capture 

 as many insects as would a net building species. 



Besides the fact of the location of the web, the manner of 

 actual capture seems to be of some importance. The Orb 

 Weavers which we have observed depend on tactile responses 

 to secure their food. If one throws something else in their 

 webs they rush at it in the same manner as if it were an insect. 

 The consequence is they roll up in their webs nearly every 

 insect that chances to strike the webs. 



The Lycosid^ and Attidae depend more on sight and can 

 see for some distance. Misumena remains perfectly quiet 

 until the insect comes to it. The instant the insect comes 

 within grasping distance there is one quick move and the 

 insect is dead. The chances of securing prey in these cases 

 are smaller in comparison to net building species. 



In studying the food relations of spiders most of the observa- 

 tions were made directly in the field. Although excursions 

 were made to many different locations, most of the data was 

 collected on an area of about eighty acres. Besides the field 

 observations, I captured a great many specimens and fed them 

 in captivity. I secured about sixty common paste-board 

 shoe boxes and a window pane to cover the top of each box. 

 With this kind of a cage I was able to watch the spiders and 



