304 THE CANADIAN ENTOMOLOGIST 



wider range, ethereal, alliaceous, hircine and nauseating odours all 

 being more or less attractive. 



The range of the Diptera is exceptionally wide, embracing 

 ethereal, fragrant, alliaceous, hircine and nauseating odours. 

 Certain species of mosquitoes, bee flies, and syrphus fiies are found 

 feeding on nectar. Eristalis tenax visits cesspools, dung-pits and 

 decaying vegetable matter in addition to different fiowers. Droso- 

 phi'idae visit decaying fruits both f^r food and egg deposition, and 

 Piophila casei is drawn toward cheese, ham and partly spoiled 

 ^'cgetable matter; while the house fiy, as everyone knows, shuns 

 r.r thing except aromatic and virulent odours. 



Robertson's records show clearly that the Hymenoptera and 

 Diptera are especially fond of fragrant odours. He found that 

 Pastinaca sativa was visited in twenty-six days by 173 Hymenop- 

 tera, 72 Diptera, 14 Coleoptcra, 9 Lepidoptera, 6 Hemiptera and 

 1 Neuropteron; also that Asclepias verticillata was visited by 52 

 Hymenoptera, 42 Diptera, 16 Lepidoptera and 3 Coleoptera. 



It would be extremely interesting to find the effect of exhaus- 

 tion upc'n the end organs of smell. A bee, for instance, visiting 

 innumerable flowers of the honeysuckle must have its organ 

 fatigued by the continuous smelling of this one odor. How, then, 

 would it react to other odours? Does its physiological mechanism 

 of smell consist of distinct parts, one of which might be put tempor- 

 arily out of commission without impairing the others, or does it 

 consist entirely of one part? 



THREE NEW GALL MIDGES (DIPTERA). 



BY E. P. FELT, ALBANY, N.Y. 



The following descriptions are of species which have been 

 reared and of one concerning which we possess some exceptionally 

 interesting data. There is much to be learned about our tropical 

 or subtropical midge fauna. There must be hundreds of interest- 

 ing and undescribed species existing in the West Indies and adjacent 

 countries. 



Karschomyia cocci, n, sp. 



The midges described below were reared from a sugar-cane 

 mea,ly bug, Pseudococcus sacchari(?) collected at Central Provi- 

 dencia, Patillas, P.R., January 30, 1913, by Mr. D. L. Van Dine. 



September, 1913 



