UNITED STATES DEPARTMENT OF AGRICULTURE 



i BULLETIN No. 264 



jM9 Contribution from the Bureau of Entomology 



"<«SFL L. O. HOWARD, Chief 



Washington, D. C. T June 15, 1915. 



THE VIOLET ROVE-BEETLE. 



By F. H. Chittenden, Sc. D., 

 In Charge of Truck Crop 1 and Stored Product Insect Investigations. 



INTRODUCTION. 



Beginning with the year 1901 a small dark-colored rove-beetle, 

 known to science as Apocellus sphaericollis Say, has been reported as 

 an enemy to violets and other succulent ornamental plants in the Dis- 

 trict of Columbia and from St. Louis, Mo. This insect is a very 

 common one in the United States and is quite generally known as a 

 scavenger, feeding on humus and decaying vegetation and similar 

 matter. That it feeds on violets as well as on a variety of other vege- 

 tation is now undoubted. Informants have furnished abundant proof 

 of this in the eaten flowers and leaves, while beetles in confinement 

 in the writer's laboratory were observed by him to attack violets and 

 other plants. Nor does the insect confine itself to plants grown in- 

 doors or in gardens, since in its Washington occurrence the violets 

 were grown in hothouses and at St. Louis the various plants affected 

 were growing in the open. There is no doubt, however, that although 

 the habit of the insect of feeding on delicate flowers and leaves is 

 well established it is nevertheless an acquired taste, the insect living 

 normally like others of its kind on old, dead leaves or in soil which 

 has been covered by leaves over winter. 



Undoubtedly injury by this species is more extensive than our 

 note- show. This may be ascribed mainly to the resemblance of this 

 insect, to the casual observer at least, to an ant, and to the fact that 

 the beetles swarm in numbers on plants in the manner of ants. The 

 year after the first report of injury by this species so many com- 

 plaintsof injuries by ants in greenhouses were made that the Florists' 

 Exchang< - a-ked the writer for an article bearing upon this subject. 



'.\ large proportion at the Infects which Infest the. garden also infest greenhouses, as 

 in tii< present Instance. Next i" roses, violets are favorite Bowers grown in this and 



some other countries, in Bulletin No. i^7, new scries, Burei t Entomology (out of 



print, i. ut available in libraries), a somewhat comprehensive publication <>n riolel insects 

 wjim furnished. 



»p, ii. c. a rlolet pest, in The Florists' Exchange, v. 86, No. 23, i>. L210, Dec. <;, 

 1013. 



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