INSECTS INJURIOUS TO BEETS AND SPINACH 



339 



spring. As injury is mostly on or near alkali ground, such soil 

 should be avoided. 



Plant-bugs 



The Tarnished Plant-bug (Lygus pratensis see page 404), 

 False Chinch-bug (Nysius angustatus), and several of the com- 

 mon plant-bugs often become so numerous as to do considerable 

 damage to beets. When present in large numbers, a spray of 

 kerosene emulsion might be used to advantage. Experiments 

 in New York show that the tarnished plant-bug can be driven 

 from a field by dusting the rows with wood-ashes, being careful 



FIG. 243. The false chinch-bug (Nysius angustatus). (After Riley.) 



to work on the same side of each row and thus gradually driving 

 them into the field adjoining. 



The Beet Leafhopper * 



Very serious loss to the sugar-beet industry has occurred in 

 Colorado and Utah from a condition known as " curly leaf " 

 or "blight." Investigations made by Professor E. D. Ball have 

 shown that the " curly leaf " is undoubtedly caused by the presence 

 of immense numbers of small leafhoppers, from 10 to 100 often 

 being found on a plant in badly infested fields. The curly leaf 

 condition does not seem to result, however, except when the soil 

 has become dry and heated, and where plants are shaded or 



* Eutettix tenella Baker. See E. D. Ball, Bulletin 66, Part IV, Bureau 

 of Entomology, U. S. Dept. Agr. 



