29 



laying continues probably through that month and at least to the 

 middle of July, if not two or three weeks later: that injury is due to 

 the beetles upon their first appearance usually, and that almost any 

 valuable crop may be injured, either in the absence or presence of 

 the wild food plants; that the larva? feed below ground, and probably 

 have a wide range of host plants in addition to those which have been 

 ascertained, which include at present only corn, lambsquarter. and 

 probably Jamestown weed. 



NATURAL ENEMIES. 



Neither predaceous nor parasitic insect enemies have been observed 

 of this species. The writer is under obligations to Dr. Sylvester D. 

 Judd. of the Division of Biological Survey, for information concern- 

 ing certain of its vertebrate enemies. During June and July, 1898, he 

 observed two species of sparrows in wheat fields near Marshall Hall, 

 Md.. feeding upon the adult flea-beetles, which were at the time on 

 Ambrosia artemisicefolia growing between the rows of wheat. The 

 chipping sparrow (jSpiseUa socialis) was observed June 16 and 17, and 

 specimens were shot and their stomachs examined. Eight of these 

 contained individuals of the flea-beetle as follows: S. 12. 5, 7, 8, 6, 12, 

 and 11 specimens in each. The grasshopper sparrow or yellow- winged 

 sparrow (Aminodramus rammnarum passerinus) was observed attacking 

 this flea-beetle July 9. 



REMEDIES. 



Dr. Fletcher has reported finding that Paris green applied dry, 

 mixed with twenty parts of flour and dusted on the infested plants, 

 was thoroughly effective against this insect, and Professor Brunei' 

 obtained equally good success by the use of kerosene emulsion. The 

 arsenites suggest themselves as the appropriate remedy, and. since 

 Bordeaux mixture has been found to be particularly distasteful to flea- 

 beetles, this substance, if mixed with Paris green and applied as a 

 spray, should prove still more valuable than when used dry. Keeping- 

 down the weeds which are known to be, or which we have good rea- 

 son to believe are, larval food plants, such as lambsquarter. cockle- 

 bur, pigweed, etc.. should also be productive of good results. A good 

 time for the destruction of these weeds would be about the middle of 

 July, when most of the beetles have laid their egg>. and the larvae 

 have not yet attained full development. By pulling up and burning 

 the weeds at this time the larva? could be destroyed in great numbers. 



Although the species is still periodical in its attacks, it is by no 

 means certain that it will not prove injurious in some localities for 

 two or more years in succession. 



