LITERATURE FOR 1911 ON THE BEHAVIOR OF 

 SPIDERS AND INSECTS OTHER THAN ANTS 



C. H. TURNER 

 Sunnier High School, St. Louis, Mo. 



TROPISMS 



t. Thigmotropism. H. H. P. and H. C. Severin (53) have 

 obtained experimental evidence that certain water bugs are 

 positively thigmotactic. In an aquarium containing water one 

 inch deep, they placed thirty-five specimens of Belostoma fliimi- 

 neum Say, and scattered on the top of the water several large 

 flat corks. In a few hours thirty-two of the insects were resting 

 against the lower sides of the corks. Frequently, at the surface 

 of the water and at the bottom of the aquarium, two or more 

 Belostomas were found clinging together. This the authors con- 

 sider a positive thigmotactic response. Belostoma americanum, 

 Benacus griseus, Nepa apiculata, Ranatra americana, and Rana- 

 tra kirkaldyi react in the same manner. 



2. Phototropism. The opinion has been hitherto held that 

 the Hepialidae fly only at twilight. J. McDunnough (36), how- 

 ever, last summer observed H. hyperboreiis flying on the north- 

 ern slope of Mt. Hood between half -past two and three in the 

 afternoon, in the sunlight, on three successive days. He thinks 

 that the species may have changed its habits on account of the 

 coldness of the evenings in that latitude. 



According to E. A. Andrews (9) termites, although blind, 

 respond to light by collecting where the intensity is least. 

 Andrews does not call this a tropism, but Bohn would. 



If the hand is passed over a jar containing larval mosquitoes, 

 all of the insects swim downwards. In order to classify this 

 behavior, S. J. Holmes (30) has performed a series of experi- 

 ments. A glass jar containing Culex territans and Culex pipiens 

 was arranged in a window in such a position that the light fell 

 upon it obliquely. Whenever a dark object was passed over 

 the jar, the larvae swam downwards and towards the side that 

 was away from'the light. When conducted in a dark room, with 

 the light impinging on only one 'side of the aquarium, the ex- 



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