U. S. D. A.. P>. K. P.iil. or.. I'ai-t VI. Issiu-rt Mn.v 8. 1909. 



SOME INSECTS IXRiRIOUS TO TRUCK CROPS. 



THE HOP FLEA-BEETLE. 



(Psylliodes imnctuluta Molsh.) 



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

 In Charge of Truck Crop and t^prcial Insect Investigations. 



INTRODUCTORY. 



A minute, metallic blackish i\ea-heetle, Psylliodes pimctulata Melsli., 

 known b}^ dilTerent local names, has been reported in recent years as 

 doing very extensive injury to the hop plant and considerable injury 

 to sugar beet. Since 100-i it has been reported in numbers on sugar 

 beets grown in several localities in Idaho, Utah, and Colorado. In 

 the Northwest, and jjarticularly in British Columbia, it does serious 

 damage in hopyards, and has been especially destructive since 1903. 

 During the past three years, indeed, this species has become unusually 

 abundant, with the result that in the Chilliwack and Agassiz Valley 

 hop-growing regions of British Columbia it has accomplished damage 

 which has been estimated by Mr. II. J. Quayle as about 80 per cent 

 of the crop. Mr. Theo. Eder informs the writer that this means a 

 cash loss of not less than $125,000 in that district. The species during 

 that period has been the subject of considerable correspondence be- 

 tween this Department and persons practically interested in the grow- 

 ing of hops in the affected region. 



The insect has received the name of rhubarb flea-beetle, from its 

 common occurrence, especially in the East, on rhubarb. In the West 

 it is called the lioj) flea-beetle, or " hop flea," or simply " flea," and in 

 literature it has received mention as the punctulated and the small- 

 punctured flea-beetle. 



While the species is not known to be of the highest importance as a 

 sugar-beet pest, the probabilities are (hat it uiay become so, and at the 

 present time it is probably the most important ho}) pest in the entire 

 world. The incorjioration of some new matter, gained from con- 

 versation with Mr. Theo. Eder and by correspondence with Mr. H. J. 



55968°— Bull. 66—10 6 "^^ 



