UNITED STATES DEPARTMENT OF AGRICULTURE 



BULLETIN No. 432 



Contribution from the Bureau of Entomology 

 L. O. HOWARD, Chief 



Washington, D. C. 



PROFESSIONAL PAPER 



December 13, 1916 



THE SPIKE-HORNED LEAF-MINER, 1 AN ENEMY OF 

 GRAINS AND GRASSES. 



By Philip Luginbill and T. D. Urbahns, Entomological Assistants, Cereal and 

 Forage Insect Investigations. 



CONTENTS. 



Page. 



Introduction 1 



Synonymy 2 



History of the species 2 



Food plants 8 



Description 5 



Distribution 7 



Injury to plants by adults punctur- 

 ing tbe leaves _ 7 



Page. 



Injury to plants by mining habits of 



larvae 8 



Life history 9 



Rearing methods 14 



Parasitic enemies 15 



Preventive measures 16 



Bibliography 17 



INTRODUCTION. 



The leaf-miner Cerodonta dorsalis Loew, although known since 

 1861, has not received much attention from economic entomologists, 

 probably for the reason that to the present time, so far as known, it 

 has not proved a serious pest, owing to the activity of its parasites 

 and to its wide range of food plants. Although known in entomo- 

 logical literature as " a corn leaf -miner," it has been observed lately 

 that the larvae work as readily in barley, millet, wheat, and various 

 grasses; in fact, in the rearing cages as well as in the field the leaf- 

 miners prefer barley and millet to corn. Wheat and oats may also 

 be included in the list of food plants, and young barley and oats 

 infested with this species may die from the injury. Oats and barley 

 plants infested with Cerodonta dorsalis present a similar appearance 

 to those infested with Meromyza americana Fitch or other species Of 

 Oscinidse, and it is possible that injury formerly attributed to the 

 work of Meromyza was in reality the work of C . dorsalis. 



56323' 



Cerodonta dorsalis Loew ; order Diptera, family Agromyzidae. 

 —Bull. 432—16 1 



