THE EUROPEAN CORN BORER AND ITS CONTROL. 69 



EXPLANATION OF PLATES. 

 All except Figs. 12, 13 and 14 drawn from sketches by R. E. Snodgras 



Plate I. 

 Fig. 1. — First larval instar. 

 Fig. 2. — Second larval instar. 

 Fig. 3. — Prothoracic shield of first two instars. 

 Fig. 4. — Third larval instar. 



Fig. 5. — Prothoracic shield of third instar; spines not shown. 

 Fig. 6. — Fourth larval instar. 

 Fig. 7. — Prothoracic shield of fourth instar; spines not shown. 



Plate II 



Fig. S. — Fifth larval instar. 



Fig. 9. — Prothoracic shield of fifth instar. 



Fig. 10. — Sixth larval instar. 



Fig. 11. — Prothoracic shield of sixth instar. 



Fig. 12. — Venation of fore wing of adult. 



Fig. 13. — Venation of hind wing of adult ma 



Fig. 14. — Frenulum of hind wing of female. 



