April, '16] BENSEL: VARIEGATED CUTWOR^I 303 



gain and this should be seriously considered where quarantine meas- 

 ures are framed. From a practical standpoint the writer does not 

 hesitate to say that if state quarantines are to be effective, the closest 

 cooperation between affected states must be established, and their 

 effect on well established lines of commerce be seriously considered 

 before they are promulgated. 



CONTROL OF THE VARIEGATED CUTWORM IN VENTURA 

 COUNTY, CALIFORNIA' 



By G. E. Bensel, Collaborator, Truck Crop and Stored Product Insect Investigations, 



U. S. Dept. of Agriculture 



Recent Injury 



The variegated cutworm {Peridroma margariiosa (saucia) Hiibn.) 

 is widely distributed in Ventura County, California, and has done con- 

 siderable damage in the last j^ear (1914) to the sugar beet crop. The 

 first serious outbreak occurred in April, 1913, when about three hun- 

 dred acres of young beets were cut off just beneath the surface of the 

 ground. These dark brown "worms" were observed concealing them- 

 selves an inch or two underground during the day time, where in a 

 dormant stage near the attacked plants they were ready to emerge 

 on the return of night. It was also noticed that they generally fol- 

 lowed the rows of beets, that very few fed during the day and that 

 most of the damage was done during the night and early morning. 

 The depredation is completed in so short a time that onh'- preventive 

 remedies could be recommended. The entire field was destroyed in 

 less than four days. This field was summer-fallowed the previous 

 year and the last generation evidently had deposited their eggs on 

 the volunteer vegetation and this outbreak was the result of over- 

 wintering larvae. This field was replanted but the cutworms destroyed 

 the stand. It was then decided to postpone the second replanting 

 with the object in mind that possibly the cutworms would, in the mean- 

 time, mature, enter the earth, and pupate. This supposition proved 

 true and the third stand was unmolested. Unfortunately a second 

 serious outbreak occurred in the same field about six weeks later. 

 This time large beets were attacked and completely stripped. Only 

 the stems were left untouched; even the roots were considerably dam- 

 aged. The cutworms eat more ravenously during cool and foggy 

 weather; hot sunshine checks to a large extent their ravages. The 

 yield of the affected field was considerably reduced and very likely the 

 sugar content of the beet was also materially reduced, as the elabora- 

 tion of the sugar occurs in the leaves, which were largely damaged. 



1 Published by permission of the Secretary, U. S. Dept. of Agriculture. 



