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



the spider dispatched her summarily. Besides what they 

 actually eat, these spiders destroy an enormous number of 

 gnats and midges which become entangled in the webs at 

 night. The webs of these spiders sometimes contain so many 

 gnats that one cannot estimate their numbers. 



When an insect gets into this spider's web, the spider 

 proceeds from the hub and ties it up. Then it returns to the 

 hub with the insect and begins sucking out the juices. If 

 another insect is thrown into the web it ties this insect up and 

 goes back and begins eating the one it was interested in before 

 the second was thrown into the web. So with a second and 

 third, usually returning to the insect it was feeding upon first. 



Sometimes each insect will be carried along on the return to 

 the hub and deposited with the insect first thrown into the web. 

 Several times I amused myself by catching a great number of 

 flies and throwing them into the web of this spider one at a 

 time. The first one was usually taken back to the hub of the 

 web, where the spider started to eat it. If a second fly was 

 thrown into the web, the spider tied it up and returned to the 

 center of the hub with it and placed it along side the first one 

 and started eating again. If still another fly was thrown in, 

 the spider repeated the performance. So on with the third and 

 fourth. This was kept up until the spider had accumulated 

 enough flies to make a small ball about the size of an English 

 walnut. Unfortunately, this was too much weight for the 

 strength of the web and it gave way. The spider had to build 

 a new web, but I repeated the performance the next night and 

 he seemed as greedy as ever. One point here, I think, is of 

 some value. No matter how many insects fly or fall into the 

 web, they are all killed. The number of insects from which 

 the spider actually sucks the juice may be small in comparison 

 to the number that are actually killed. In this case the good or 

 bad accomplished by the spider cannot be judged by the number 

 of insects that it actually eats. If the insect is injurious, as is 

 most often the case, the number that is 'destroyed does not 

 depend on the spider's capacity, but upon the abundance of the 

 insect. Many spiders have the habit of tying up every insect 

 that happens to get into their webs. Where such spiders are 

 abundant we have found them more abundant than the non- 

 net building species, they play an important role in keeping 

 insects in check. 



