16 
BULLETIN 571, U. S. DEPARTMENT OF AGRICULTURE. 
For some reason, presumably because the twigs were kept in too 
dry a condition, many larvae failed to emerge from hibernacula that 
were not treated, as is shown in Table IX. The best results were 
obtained with undiluted miscible oil, while strengths ranging from 
1 :12 to 1 :20 gave considerably less benefit for the treatment, as 
was also the case when 10 and 20 per cent kerosene emulsions were 
employed. Commercial lime-sulphur solution at 1 :8 and 40 per cent 
nicotine sulphate at 1 :32 ranked second in effectiveness. 
Further dipping tests were made with commercial lime-sulphur 
solution on March 26, 1914. The strengths employed were 1 :8 and 
1 :10, in which thirty heavily infested pecan twigs were dipped, and 
after the treatment the twigs were caged immediately in jars and 
placed in the out-of-doors insectary. By March 31 many of the 
larvae were emerging from their hibernacula and feeding upon the 
developing buds. Further observations showed that lime-sulphur 
at these strengths was not effective in preventing many larvae from 
emerging from winter quarters. 
Table X shows further dipping and spraying experiments with 
lime-sulphur and miscible oil. 
Table X. — Dipping and spraying experiments for destruction of hibernating larvae of the 
pecan leaf case-bearer at Monticello, Fla., in 1916. 
Experi- 
ment 
No. 
Treatment. 
Date of appli- 
cation. 
Result. 
II 
in 
rv 
Dipped twigs in commercial lime- 
sulphur solution (1:8), testing 32° 
Baume. 
Sprayed twigs with commercial lime- 
sulphur solution testing 32° Baume. 
Sprayed twigs with miscible oil at 1 :15 . 
Check; twigs untreated 
Mar. 7,1916 Many larvae emerged and destroyed 
every bud. 
do Many larvae emerged and destroyed 
most of the buds. 
Many larvae emerged and destroyed 
practically every bud. 
Larvae emerged and readily destroyed 
every bud. 
.do 
The twigs used in these experiments were kept in water or moist 
soil in order to insure the proper development of the buds. The 
first observations were made on April 17, 1916, and results as shown 
in Table X indicate the condition of the f oliage. It will be noted that 
the lime-sulphur and miscible oil failed to destroy the larvae. 
SPRAYING EXPERIMENTS! FOR THE DESTRUCTION OF LARYJE IN HIBERNATION. 
A series of spraying experiments was conducted with several of the 
standard winter sprays to find out their effect upon larvae in hiber- 
nation, and in all cases the material was applied thoroughly by means 
of a gasoline-power outfit. 
1 The spraying was done in bearing pecan orchards belonging to the.Standard Pecan Co. and the Summit 
Nurseries, both of Monticello, Fla., and to Mr. Charles E. Pabst, of Ocean Spring, Miss. 
