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



The percentage of insects used as food is based upon ninety- 

 seven spiders which were observed feeding and is as follows : 



20% consisted of Bumble Bees; 20% consisted of Tipulid^; 17% con- 

 sisted of other Diptera, chiefly Syrphidae; 5% consisted of Grasshoppers; 

 5% consisted of Noctuid moths; 4% consisted of Lygus pratensis; 

 3% consisted of Apis mellifica; 4% consisted of Vespa germanica; 2% 

 consisted of Vespa maculata; 2% consisted of Ichneumonidee; 2% con- 

 sisted of Jassids; 2% consisted of Ceresa bubalus; 2% consisted of 

 Tiphia inomata. ' . ,■ . • ■ 



A striking fact about the food of those spiders which were 

 observed was that Bumble bees made up a large part of the food 

 while the highest per cent of any insect eaten by its near relative, 

 Epeira trifolium, was honey bees. This again is explained by 

 the location of the webs. Epeira trifolium is more abundant 

 among wild flowers in fields, while Epeira gigas made its web 

 most often in open places, in woods and among shrubs. Crane 

 flies, which are abundant in woods in late summer and fall, also 

 formed a large part of the food. In such places Grasshoppers 

 are less abundant and so formed a smaller per cent of the food 

 than that of most other spiders. Syrphid flies were abundant 

 in such a place and so entered into the food to a considerable 

 extent. One would not expect many leaf hoppers in such a 

 place and such is the case, only 2% of the food consisting of 

 Jassids. Like the other large orb weaving spiders, the food of 

 this spider where it has been observed is not relegated to any 

 particular insect, but depends largely on what kind is at hand 

 to be eaten. 



Argiope trifasciata Forskal. 

 This spider has a number of names all of which are suggestive 

 of the peculiar striped back. It was very abundant in the places 

 where it was studied. The web is the common orb type and 

 may or may not have barrier webs. It is of considerable diam- 

 eter, usually from a foot to a foot and one-half from top to 

 bottom, and is made vertically or slightly inclined. There are 

 two or three types of stabilimentum and there may be no 

 stabilimentum at all. In one type the stabilimentum reaches 

 vertically through the web and is comparatively narrow. In 

 another type which is not so common as the former the sta- 

 .bilimentum is irregular in shape being somewhat like a truncated 

 cone narrowed at the base. Late in the season many webs do 

 not have- a stabilimentum. This is probably due to the fact 



