SOME SUGAR-CANE ROOT-BORING WEEVILS OF 

 THE WEST INDIES 



By W. DwiGHT Pierce, 



Entomological Assistant, Investigations of Insects Affecting Southern Field Crops, 



Bureau of Entotnology 



INTRODUCTION 



Sugar-cane {Saccharum officinarum) growers throughout the world find 

 among their most serious enemies the weevils which bore in the subter- 

 ranean portions of the stalks and the root crown. The methods of 

 cultivation and propagation in vogue in the sugar-cane industry make 

 an attack of this nature more serious than injury to another part of the 

 plant. 



In the West Indies one of the most important groups of economic 

 weevils is the genus Diaprepes, w^hich is mainly confined to the periphery 

 of the Caribbean Sea. The present paper deals with the weevils of this 

 genus which attack sugar cane and which are popularly known as sugar- 

 cane root borers. The writer's purpose is to straighten out the difficult 

 nomenclature, to point out the dangerous nature of the injury by the 

 species treated, and so to describe the various forms that quarantine 

 agents may readily detect them. 



These weevils are so variable in color, shape, and markings that it is 

 extremely difficult to come to a definite decision as to their specific limi- 

 tations. Many names have been used which can only be considered of 

 varietal significance or as mere synonyms. The same species is likely to 

 be known by different names in different islands. It is therefore neces- 

 sary to go a little deeply into the description of the various forms and to 

 trace the blending from one form to another through the islands. For 

 this reason the technical matter must receive more attention than the 

 biological and economic data belonging with it. 



GENUS DIAPREPES 

 THE ADULT 



The genus Diaprepes Schonherr contains many species found in the 

 West Indies, Mexico, and Central and South America. It is typically 

 tanymecine in the possession of distinct ocular vibrissae on the prothorax 

 in the majority of species, although occasional specimens of undoubted 

 Diaprepes are found without trace of the vibrissge. The genus is dis- 

 tinguished by the peculiar irregularities of the elytral striae, which num- 



Joumal of Agricultural Research, Vol. IV, No. 3 



Dept. of Agriculture, Washington, D. C. June 15, 1915 



91007°— 15 5 (255) 



