BUREAU OF ENTOMOLOGY AND PLANT QUARANTINE 47 
MUSHROOM INSECTS 
In the investigation on mushroom pests special emphasis has been placed 
on possible use of napthalene and paradichlorobenzene. Chemists of the 
Division of Insecticide Investigations have been associated with these studies. 
QUARANTINE ON DOMESTIC NARCISSUS 
The narcissus-bulb quarantine was revoked, effective April 1, 1935. This 
action was taken because attempts at general eradication of the eelworm and 
the greater bulb fly had not been successful, the pests occurring year after year 
in most areas where such attempts had been made. Furthermore, both these 
pests have become established in commercial bulb plantings in many States in 
addition to those in which they were known to occur in 1920, when the quar- 
antine was established. 
The removal of the Federal quarantine left the interested States free to act 
in placing such restrictions as they deemed advisable. The State of Oregon 
thereupon issued a quarantine on the entry of narcissus bulbs, with inspection 
and fumigation requirements similar to those formerly in effect under the Fed- 
eral quarantine. State officers of Florida, Virginia, Pennsylvania, Michigan, 
and Texas announced that inspections of narcissus would be made the same as 
when the Federal requirements were in effect, and Maryland officers announced 
their intention of continuing inspection of these bulbs as part of the general 
nursery-inspection program. 
For the season of 1934 the State nursery inspectors in 27 States reported to 
the Bureau the inspection of 235,486,0S5 narcissus bulbs. Detailed information 
on the number of plantings and bulbs and the extent of treatment in the indi- 
vidual States is given in Circular B. E. P. Q.-373, issued on April 23, 1935. 
From July 1, 1934, to April 1, 1935, 154 violations of the quarantine were 
intercepted at transit-inspection points. 
COTTON INSECT INVESTIGATIONS 
The issuance of information on the distribution and abundance of insects 
attacking cotton, together with timely advice on methods for their control, was 
resumed during the year. Reports about cotton insects were included in the 
Insect Pest Survey Bulletin and in press releases and radio broadcasts along 
the same general lines followed with insect pests of other crops. 
BOLLWEEVIL 
The initial bollweevil infestation in the crop season of 1934 at Tallulah, La., 
was comparatively high, but the hot, dry weather from June 18 to the end of 
August held the weevils in check. Experimental plots dusted with calcium 
arsenate following standard recommendations gave an average increase of only 
236 pounds of seed cotton per acre, or 19.5 percent, as compared to 419 pounds, 
or 45.4 percent, during the previous year. 
A large series of field and cage tests were conducted to determine the efficacy 
of a number of insecticides, mixtures of insecticides, and insecticides diluted 
with carriers. The tests at Tallulah showed the value of several other mate- 
rials for bollweevil control, but none was found to be superior to calcium 
arsenate dust. Mixtures of calcium arsenate and hydrated lime, mixtures of 
paris green and lime, and a mixture of calcium arsenate and copper arsenite 
gave good results. These preliminary results suggest that these materials may 
be useful for regions where it may be desirable to reduce the amount of arsenic 
used or when other insects, such as the cotton flea hopper and cotton leaf worm, 
must be controlled along with the bollweevil. Tests with thiodiphonylamine 
(phenothiazine) and sulphur, and with derris root in inert carriers, indicate that 
these may have a place among effective nonarsenical poisons. Tests conducted 
to compare the results from dusting with calcium arsenate early in the morning. 
at midday, and late in the evening were favorable to the early morning appli- 
cations ; and tests to compare the results of dusting at 4- r 6-, and 8-day intervals 
were favorable to the 4-day program. 
For the third year in succession, in tests at Florence, S. C, a mixture of equal 
parts of hydrated lime and calcium arsenate was as satisfactory for the control 
of the bollweevil as calcium arsenate alone when each was used at the rate of 
about 7 pounds per acre per application. Other mixtures of lime with calcium 
arsenate and with paris green gave good results. 
