1911] Food Habits of American Gall Midges (il 



while Carya and Quercus arc subject to attack by 25 and 21 

 species, the former affording support to representatives of 

 5 and the latter to species belonging to 7 genera. These two 

 trees are likewise comparable in that each supports but one 

 species in the fruit, while by far the greater majority of the 

 midges, namely 23 and 18 respectively, produce leaf galls. 

 The large family Leguminosae has 13 genera which support 

 some 5 genera of gall midges referable to 20 species, 3 living in 

 fruit, 3 in bud, in leaf and 8 in stem galls. ( )nly ii genera in the 

 Urticaceae are attacked by gall midges belonging to 4 genera 

 representing 8 species, 2 living in bud, 9 in leaf and (> in stem 

 galls. In the Vitaeeae, Psedra, and Vitis support some 12 

 genera of gall midges representing 17 species; 4 inhabit bud, 

 12 leaf and 1 root galls. By far the great majority of the 

 species, 15, occur upon Vitis. The large family of Labiatae 

 supports some (> genera representing only 13 species, the 

 Caprifoliaceae, 8 genera comprising 14 species, and the import- 

 ant Pinaceae G genera and 14 species. The above record, while 

 dealing with a much larger number of species than we have been 

 accustomed to think occurred in this family, shows that in all 

 probability there are many forms yet to be discovered. 



Comparing the above data with recently summarized records* 

 it will be seen that the food habits of some 420 European gall 

 midges representing 43 genera are unknown. The Pinaceae 

 afford sustenance to 11 species belonging to 4 genera, a condi- 

 tion closely paralleled in this country. The European Grami- 

 neae support some 20 gall midges representing 7 genera, a show- 

 ing somewhat below what obtains in America. Conversely, 

 the European records for the Cyperaceae include 4 genera and 

 9 species, while in this country but one species has been reared 

 from Scirpus. The European Salicaceae supports some 30 

 species of midges belonging to genera, 5 of these occurring 

 on poplar. There appear to be no species affecting the Juglan- 

 daceae in Europe. There are nearly as many genera and specie 

 20 and 7 respectively, occurring upon the Fagaceae in Europe 

 as in America, though the distribution is different, since Fagus 

 supports 5 species referable to 3 genera and Quercus has only 

 14 species representing 4 genera, a marked contrast to condi- 

 tions obtaining in this country. There is a pronounced differ- 



* 1909, Houard, C. Les Zoocecidies des Plantes d'Europe. 



