FLEA-BEETLES 329 



larva enters the petiole, where it burrows through the tissue, 

 often causing the death of the leaf. Its presence is indicated 

 by brownish, dead areas where the larva has come near the 

 surface. The mature larva is nearly i inch in length, slender, 

 pale yellowish white, with the head, thoracic shield and anal 

 plate dark brown. From seven to over nine weeks are required 

 for the larva to reach maturity. It then descends to the ground, 

 where it transforms to a small white pupa in an earthen cell 

 and in ten days to two weeks the beetles emerge. There is 

 only one brood annually. The beetles are more destructive 

 early in the season and the larvffi later. Tlie foliage is injured 

 to such an extent that the roots do not develop and the crop is 

 consequently shortened. 



Control. 



The plants may be made distasteful to the beetles and some 

 of them poisoned by thorough spraying with bordeaux mixture 

 containing 4 or pounds of arsenate of lead (paste) in 50 gallons. 

 When the pest is abundant, several applications at intervals 

 of two or three weeks may be found necessary. In some cases 

 it is advisable to change the location of the beds yearly to new 

 land in order to escape attack by the beetles. 



Reference 

 U. S. Dept. Agr. Bull. 5.35. 1917. 



The Spinach Flplv-Beetlfv 



Disonycha xanthomelo'n.a Dalman 



So far as known, this flea-beetle has been injurious only to 

 beet, spinach and salt-bush. Its wild food plants include 

 lamb's quarters, pigweed and chick-weed. The insect is dis- 

 tributed throughout the United States and Canada east of the 

 Rockv Mountains. 



