IMPORTANT PECAN INSECTS AND THEIR CONTROL. 



9 



two essentials that must be observed most faitlifully, for oven the 

 slightest delay or carelessness in applying the spray is likely to result 

 in very disappointing returns from the treatment. Since the eggs 

 of the fn-st brood of moths are hatching for a period of fully two 

 weeks, and as the nuts are growing very rapidly at this time, it is 

 necessary to make two applications for the protection of nuts against 

 infestation by the firet-brood larvse, which, as has been stated before, 

 invariably cause the most damage to the crop. It has been found 

 necessary to spray once for the second-brood larvae, wliich usually 

 begin to bore into the nuts shortly after the middle of June. 



RECOMMENDATIONS. 



Investigations conducted so far show that the best method of con- 

 trol against the pecan nut case-bearer is spraying with arsenate of 

 lead. The ai-senate of lead should be used at the rate of 1 pomid of 

 the powdered form or 2 pounds of the paste form to each 50 gallons 

 of water, to which should be added the milk of lime from 3 pounds 

 of slaked lime. Tliree applications will be required and should be 

 made at the following periods: 



First. — Shortly after the nuts have set, at which time they are 

 about the size of garden peas. 



Second. — One week or ten days after the first application. 



Third. — ^Four or five weeks after the second application. 



The date for the first application at MonticeUo, Fla., during the 

 season of 1916, was found to be May 12. It should be borne in 

 mind, however, that the time of 

 spraying probably wiU vary some- 

 what according to latitude and 

 for different seasons. 



THE PECAN SHUCKWORM.i 



A rather slender, white larva 

 or caterpillar (fig. 7, at right), 

 about three-eighths of an inch 

 in length, is found mining the 

 shucks of pecan and hickory dur- 

 ing the autumn months. This 

 caterpillar is referred to com- 

 monly as the pecan or hickory 

 shuckworm, or huslcvvorm, and 

 for the discussion of the insect 

 in this bulletin the name pecan 

 shuckworm is employed. The 

 mming ortimneling of the shucks 

 often results in the improper de- 

 velopment of the nut kernels and 



'^Laspeyrcsia caryana Fitch. 

 100737°— Bull. 843—17 2 



— Thoiiccan sliuckworm (Laspeyresia caryana): 

 Pupa at left, larva at right. Enlarged. 



