THE SPIKE-HORNED LEAF-MINER. 3 



stem of wheat, June 1, at Nashville, Term., by Geo. G. Ainslie, and 

 was reared by him the same year from mines in leaves of corn at 

 Hurricane, Tenn. During the period from July 23 to September 7, 

 C. N. Ainslie reared it from leaf mines in timothy collected along the 

 banks of ditches about Ely, Nev., September 1, and also from mines 

 in the leaves of Hordeum at Salt Lake City, Utah, during the follow- 

 ing September, and again from the same material early in March, 

 J 912. 



During 1911 the senior author reared it from leaves of Panicum 

 miliaceum at La Fayette, Ind., and followed the species o nthe same 

 plant from June 4 to July 29, 1912, when he was transferred elsewhere, 

 after which the work was continued throughout the remainder of the 

 season by W. J. Phillips. This was the first attempt made to study the 

 development of the species continuously throughout the year. Dur- 

 ing June, 1913, G. G. Ainslie found a number of mines in the leaves of 

 corn at Nashville, Tenn. All the mines were empty save one, which 

 contained a hymenopterous parasite of this species. On July 7, at 

 the same place, he found a larva mining in crab grass {Eleusine 

 indica) , which pupated on the same day and became adult on July 17. 

 During 1913 V. L. Wildermuth and E. N. Wilson made some observa- 

 tions on the life history of this species (March to November) at 

 Tempe, Ariz. The senior author again continued his study on the 

 life history of the species at Columbia, S. C, in 1913, from May 4, 

 when larvse were first found mining in the leaves of corn in the 

 field, until June, when experiments were discontinued for the year, 

 owing to imperfect facilities for continuing the work at that time. 

 In May, 1914, he again took up the investigation and continued the 

 work throughout the remainder of the year. 



During February, 1914, the junior author began an investigation of 

 this species in the San Fernando Valley of California, where it was 

 attacking grains. Observations were later extended to the Yuma 

 Valley, in Arizona, and San Joaquin Valley, in central California. 

 Observations on the life history of the species were made in the 

 laboratory at Glendale, Cal., from February to June, and at Pasa- 

 dena, Cal., from July to April, 1915. Adults and parasites, of this 

 species were again reared during March and April, 1914, from mines 

 in leaves of corn at Lakeland and Orlando, Fla., by G. G. Ainslie. 

 Such mines were very common in leaves of corn during this time. 



FOOD PLANTS. 



This species breeds in a large variety of food plants belonging to 

 the order Graminacese. Although it appears to be most frequently 

 found breeding in leaves of corn and barley, it shows a decided fond- 

 ness for the grasses, especially the millets {Panicum spp.), in which 

 it has been found to breed very freely. 



