16 Annals Entomological Society oj America [Vol. XI, 



EXPLANATION OF PLATES. 



Plate L 



Fig. L Outer leaf of iris showing the characteristic mines made by the larva of 

 Agromyza later ella. The broken places in the mines indicate where 

 the larvae have mined to the opposite side of the leaf. 



Fig. 2. Full grown larva, contracted, just before pupation. 



Fig. 3. Egg, dissected out of the ovary of the female. 



Fig. 4. Adult fly, female. 



Fig. 5. A leaf-bundle cut open to show the course of the larva as it mines down 

 towards the new forming leaf. 



Fig. 6. Ovipositor of female, side view. 



Fig. 7. Ovipositor of female, dorsal view. 



Fig. 8. Pupa, dorsal view. 



Fig. 9. A young iris plant in spring, showing the leaf-gall. Notice the evidence 

 of the mine, indicated by the unshaded part in the tip of the leaf, 

 where the larva entered the tip of the gall-forming leaf. 



Pl.\te II. 



Fig. 1. Iris versicolor, showing the condition of the plant in late fall or winter. 



The unshaded leaves represent the old dried or dead leaves. The 



shaded leaves represent the green offsets which will form next year's 



growth. In the center of the old plant is found the pupa. This center 



also remains alive. The innermost leaf is represented by the dotted 



lines. 

 Fig. 2. Mandible or rasping organ of the larva of the iris fly. 

 Fig. 3. Thoracic spiracle of the larva. 

 Fig. 4. Anal spiracle of the larva. 

 Fig. 5. Nearly full grown larva. 

 Fig. 6. Cross section of a gall, showing the pupa in the center. Note the spongy 



nature of the gall. 

 Fig. 7. Basal portion of an outer leaf of iris, showing the little swelling produced 



by the early maturing larvae which pupate in this portion of the leaf. 

 Fig. 8. Cross section of an iris plant at a in Fig. 9. This shows the arrangement 

 of the leaf-bundle. Each sheath has been separated slightly from the others to 



bring out the structure more plainly. 

 Fig. 9. Outer sheaths of the leaf-bundle torn away to show the larva entering 



the inner leaf just before pupation. 

 Fig. 10. Same as Fig. 9, after the larva has entered and pupated. 

 Fig. 11. Egg punctures on the leaf. The structure of the ovipositor indicates that 



these are abrasions, rather than punctures. 



Note — Figures 2, 4, 8 and 9 of Plate I, and Figures 6 and 7 of Plate 

 II, have been drawn for me by Miss Ellen Edmonson, of Lawrence, 

 Kansas. The remaining figures are my own. 



