364 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 5 



in great variety, especially since the spread of the Argentine Ant to so 

 many parts of the state. 



The great desideratum is the improvement and standardization of 

 the great host of what may be called the minor insecticides. Those 

 that are used in the spraying of orchard trees have been reduced to 

 a good degree of uniformity, due to the work of the economic ento- 

 mologists and the use of these preparations correspondingly enlarged 

 as the users appreciated more fully their reliability. 



The California insecticide law will go far to standardize the other 

 insecticides by giving publicity to their composition, provided that 

 we contribute our share in the study of their relative efficiency. 



THE PETROLEUM FLY IN CALIFORNIA 



By D. L. Crawford, Stanford University, California 



(Printed in Pomona Journ. Ent., Vol. IV, No. 2, Maj^, 1912, 



pp. 687-97.) 



DIABROTICA VIRGIFERA LEG. AS A CORN ROOT-WORM 



By C. P. Gillette 



Diahrotica virgifera Le Conte; Trans. American Entomological Society, Volume 

 II, page 59; 



Diahrotica filicornis Horn: Trans. American Entomological Society, Volume 

 XX, page 94. 



The last week in July, 1909, a neighbor told me that his sweet corn 

 was being killed by a little grub boring in the roots. A week later, 

 I went to examine the corn and found the adult beetles of the above 

 species abundant, resting on the leaves and stems of the corn and 

 quickly taking wing when approached. The grubs had practically 

 all left the roots but the injuries to the roots and crowns were every- 

 where present, very few plants escaping the attack. The owner said 

 there were plenty of grubs in the roots during July. Figure 1 of the 

 accompanying plate was drawn from a corn stalk taken by Mr. L. C. 

 Bragg on July 12th of the following year and fairlj' represents the 

 injury that the larvae do. 



On July 2, 1910, I received a card from Mr. R. C. Aiken, of Love- 

 land, Colorado, stating that fully one-third of his sweet corn was prac- 

 ticallv dead from the attacks of a small white worm in the roots. Mr. 



