124 A MANUAL OF DANGEROUS INSECTS. 



Description: Fly of equestris red, of the other two orange yellow. Maggot of eques- 

 tris blood red, of the other two orange or yellow. Breed in the stems and cause gall 

 formation. 

 SoRAUER, P. Handbuch der Pflanzenkrankheiten, 3d ed., 1913, vol. 3, pp. 442, 



447, 448. 



Lasioptera cerealis Lindeman. 



(Rye Midge. Itonididae [Cecidomyiidae]; Diptera.) 



Hosts: Rye, Triticum repens, Calamagrostis lanceolata. 



Injury: Attacks the stems. 



Description and biology: Fly black, abdomen white banded; 3 mm. long. Larva 

 brick red, 5mm. long. 



Distribution: Russia. 

 SoRAUER, P. Handbuch der Pflanzenkrankheiten, 3d ed., 1913, vol. 3, p. 457. 



Mayetiola avense Marchal. 

 (Oats Gall Midge. Itonididae [Cecidomyiidae]; Diptera.) 



Host: Oats. 



Injury: Forms galls in the stems. 



Description and biology: Fly black, marked with red, with a band of silver-gray 

 hairs on each side; length 3.2 mm. Has two generations. 



Distribution: France. 

 SoRAUER, p. Handbuch der Pflanzenkrankheiten, 3d ed., 1913, vol. 3, p. 449, fig. 



272. 



>|=Pliytophaga (Mayetiola) destructor Say. 



(Hessian Fly. Itonididse [Cecidomyiidae]; Diptera.) 



The well-known Hessian fly is a conspicuous example among our imported pests. 

 It is now distributed over Asia, Europe, and North America. 



Porricondyla cerealis Sauter. 



(Grain Maggot. Itonididse [Cecidomyiidae]; Diptera.) 



Hosts: Barley, oats, rye, spelt. 



Injury: Occasionally injurious. Breeds behind the leaf sheath. 



Description and biology: Fly, antennae 13-jointed, thorax black, abdomen red, 

 length 2.2 mm. Maggot, 3 mm. long, chrome red. 



Distribution: Germany. 

 SoRAUER, p. Handbuch der Pflanzenkrankheiten, 3d ed., 1913, vol. 3, p. 441 



Hylemyia coarctata Fallen. 



(Wheat Bulb Fly. Anthomyidae; Diptera.) 



Hosts: Rye, wheat, barley. 



Injury: Feeds in the stems; very destructive. 



Description and biology: Fly yellowish gray, strongly bristled; thorax without 

 stripes; abdomen with dark median stripe; antennae black; length 7 mm. Maggot 

 yellowish, 6 mm. long. (See plate xxix figs, i, n.) 



Distribution: Middle and north Europe. One specimen is recorded from Colorado. 

 SoRAUER, P. Handbuch der Pflanzenkrankheiten, 3d ed., 1913, vol. 3, pp. 431, 432, 



fig. 263. 



