May, 1920] Studies in Food of Spiders 229 



Professor Edouard Haeckel, Bulletin So. France et Belgique, 

 Vol. XXIII, 1891, says that the food is confined to two species 

 of Diptera. The observations I have made, although they 

 may not be as complete as Mr. Haeckel's, do not bear out 

 this statement. 



Dolomedes tenebrosus Hentz. 

 Dolomedes tenebrosus is one of the largest of our spiders. 

 It lives under the bark of trees, in bushes, and usually near the 

 water. The female carries her egg sac in her cheliceras and 

 before the young are ready to hatch she makes a web for the 

 young spiderlings to live upon. One of these spiders which 

 was captured under the bark of a red oak log was kept in cap- 

 tivity and she raised two broods during the summer. This 

 spider was not abundant at Crestline and the food records are 

 only for one individual. 



Dictyna frondea Emerton. 



This is one of the very small spiders and was frequently 

 found on small bushes, especially blackberry and raspberry 

 bushes. It makes an irregular web on the top of leaves by 

 drawing the edges of the leaves together. No retreat is con- 

 structed and the spider remains in the web all the time. 



If one looks on top of -leaves on bushes in clearings he is 

 almost certain to find this spider. They are so small that they 

 are easily overlooked. 



The food of this spider consisted chiefly of a small fly 

 belonging to the Anthomiid^ and the horn fly, Haematohia 

 serrata. The Dolichopodidae also formed part of their food. 

 An occasional Jassid jumped into the web and if it was not too 

 large to destroy the web, it was also eaten. Midges {Ckirono- 

 midce) and mosquitoes formed a small part of their food. 



From an economic standpoint this spider is not as important 

 as many of the larger spiders, but the fact that they destroy 

 a considerably number of flies and mosquitoes makes them of 

 some importance at least. 



Agelena naevia Walckenaer. 

 Even the casual observer has noticed the web of this spider. 

 The webs are most often in grass, but they may be made in a 

 great many other places, such as among stones, around windows 

 in buildings, on brush piles and a great variety of places. 



