ORDER DIPTERA 



259 



leaf -miner by Britton (1895) and the spike-horned leaf -miner 

 by Luginbill and Urbans (1916), whose figures we copy and 

 whose account of its habits we abstract. 



Fig. 82. The spike-horned leaf -miner, Cerodonta femoralis. 1, adult 9 ; 

 la, head of same; 2, leaf -blade showing egg in situ; 2a, an egg greatly en- 

 larged; 3, larva, enlarged; 4, puparium, dorsal view; 5, section of barley- 

 stem, showing usual position of puparium beneath the sheath. (From 

 Luginbill.) 



The female fly selects a suitable place for oviposition, 

 usually near the tip of the leaf or along the edge. With 

 head elevated and tip of abdomen lowered, the body is held 

 almost perpendicular to the leaf surface, and by rapid pierc- 



