THE SPRING GRAIN- APHIS OR " GREEN BUG." 41 



FOOD PLANTS. 



This insect has a very wide range of host plants and can on that 

 account find fresh food at any season of the year. In this way it is 

 enabled to perpetuate itself over vast areas of country and under 

 almost every variety of climate. 



Rondani, who first described the species in 1852, gives the following 

 list of host plants: Oats (Avena sativa); wheat (Triticum vulgare); 

 spelt (Triticum spelta); Arrhenatherum elatius (Avena elatior); couch 

 grass ( Triticum repens) ; Hordeum murinum; Lolium perenne; Capri- 

 ola (Cynodori) dactylon; soft chess (Bromus Tiordeaceus) (mollis); and 

 corn (Zea mays). He states also that Toxoptera had been found 

 quite abundant upon the foliage of rice (Oryza sativa) and common 

 barley (Hordeum vulgare). We find no other references to its being 

 found upon rice. In 1863 Passerini adds sorghum (Andropogon sp.) 

 and he also observed it on barley. 



Macchiati, in 1882, added the following hosts: Dactylis glomerata, 

 Bromus erectus, and B. viUosus (maximus); in 1883 he added Triticum 

 viUosum, Avena fatua, and A. oarbata; in 1885, Poa annua. 



Del Guercio, in 1906, mentions it as occurring upon buckwheat 

 (Fagopyrum esculentum). This is the first and only reference we 

 have found in which it has been accused of infesting plants other than 

 those belonging to the Gramineae. 



Toxoptera was first observed upon wheat and oats in the United 

 States. In 1889 the senior author observed it feeding upon rye and 

 in 1890 he found it plentiful at Lafayette, Ind., upon Dactylis glomerata. 

 In 1907 he found it destructively abundant upon the same grass at 

 Midlothian, Va. This infested field was from 4 to 5 miles from wheat, 

 oats, or rye fields. In Insect Life, 1 he states that Toxoptera will 

 live upon the leaves of all kinds of grains, including corn, during 

 summer. In 1902 he found Toxoptera feeding upon cheat (Bromus 

 secalinus) and rye grass (Elymus canadensis) at Peotone, 111. 



The junior author found it quite abundant on volunteer corn plants 

 among oats on April 2, 1907, at Hobart, Okla. A cornfield hear a 

 badly infested wheat field was found to be suffering also. Mr. C. N. 

 Ainslie of this bureau, on April 4 of the same year, at Kingfisher, 

 Okla., found a cornfield that was seriously injured by Toxoptera. 

 Farmers in Oklahoma were very much disturbed over the prospect 

 that the corn also would be swept away by the " green bug," but later 

 developments proved that it was not a serious pest to corn. The 

 junior author found Hordeum pusillum and Alopecurus geniculatus 

 badly infested on April 12 at Kingfisher, Okla., and Agropyron occiden- 

 tal was found harboring the pest in large numbers at Hooker, Okla., 

 in May. The senior author, Mr. Ainslie, and Prof. E. A. Popenoe, 



i Insect life, Div. Ent., U. S. Dept. Agr., vol. 4, p. 245. 



