THE DESEET CORISr FLEA-BEETLE. 21 



or three times a year, or to pasture them with sheep, thus keepmg 

 down all weed and grass growth. 



ELIMINATION OF HIBERNATION QUARTERS. 



Cleaning up weeds and grasses will eliminate a great many of the 

 hibernation quarters of this beetle, and if such methods can be car- 

 ried further, to include all waste places and any place where trash 

 may accumulate, then the hibernating beetles will not be able to 

 protect themselves from the colder days and frosty nights of the 

 winter months and thek numbers will be reduced. 



SUMMARY. 



The desert corn flea-beetle is present in injurious numbers in the 

 cultivated areas of the southwestern United States, where it takes 

 an annual toll upon such crops as corn, milo maize, sugar cane, 

 Sudan grass, wheat, barley, and alfalfa. Both the adults and the 

 larvae are concerned in injuring crops, the adults feeding upon the 

 top of the plant and the larvae upon the roots. 



The eggs are deposited at or near the surface of the ground and 

 hatch in about six days. The young larvae are found within the tender 

 roots of the food plants, while the older larvae a,re found in the soil 

 near these roots. The average length of the larval stage is found to 

 be 32 days. 



The prepupal and pupal stages are both passed within a cell in 

 the soil near to the roots on which the larvae fed. 



The flea-beetles hibernate in the adult stage under rubbish or at 

 the base of various grasses growing in the regions of mfestation. 



The total length of the life cycle of this flea-beetle is about seven 

 weeks, there being from three to four generations each year. 



The numbers of adult flea-beetles can be reduced greatly by 

 cleaning up hibernation quarters and eradioatmg some of their weed 

 food plants, such as Johnson grass, salt grass, and Bermuda grass. 

 They can be further reduced by carefully cultivatmg such crops as 

 can be cultivated just as soon as the soil becomes dry, following each 

 inigation. This method destroys a great many pupae. Small 

 pieces of corn can be sprayed successfully with arsenate of lead, using 

 2 pounds to 50 gaUons of water, the water being made into a strong 

 soap solution. This acts both as a repellent and as a poison to the 

 bcetl<;s. 



Injui-y to oorti and other crops ciui Ix', ovi'.i'coim^ partially if tlie 

 soil is placed in the best possible cultural condition by the addition 

 of barnyard manure or other f<^rtilizei-. 



The nymphs and adults of a predacious hemipteron (Reduviolus 

 ferus L.) were observed to feed upon these beetles, and a small 

 parasitic wusj), Neure'pyris sp. (fig. 7.), was found to pr<'y upon the 

 larvie and ])repupai. 



