INJURING THE STALK AND LEAF. 



229 



The Wheat Bulb Worm. 



Meromyza americana. 

 This insect has attracted the attention of economic- 

 entomologists only during comparatively recti it 

 years. The adult is a handsome two winged fly 

 (Fig 122, d), having two longitudinal yellowish 

 stripes along its back. The females deposit eggs in 

 the fall on the young wheat plants, and the larva', 

 on hatching, feed upon the central portion of the 

 stem, just above the bulb of the plant. They remain 



here through the 

 w i n t e r, becoming 

 full-grown in spring. 

 They are then foot- 

 less cylindrical lar- 

 vae of the f o r m 

 shown at b. They 

 pupate in the spring 

 and a fortnight later 

 emerge as flies. Af- 

 ter mating, the female flies of this brood deposit eggs 

 for larvae which work in the straw, just above the 

 last joint, thus cutting off the sap supply from the 

 head and causing it to wither and dry up. These 

 larvoe complete their transformations during July, 

 when they are on the wing as flies. Early in July 

 eggs are deposited by this brood of flies on volunteer 

 wheat, and the transformations of these are com- 

 pleted in time for the adults to lay their eggs in the 



Fig. 122. Wheat Bulb Worm : a, egg ; b, 

 larva : c, puparium : d, fly. Magnified. 



