20 AXXIWL RKPoRTs OF I >K PART MK XT OF A( iKK ' FLTFRE, 19 4 
the larger Delaware nurseries. Another temporary inspector was 
stationed during March at a large greenhouse establishment in the 
Philadelphia area to handle the many shipments of certified Easter 
plant-. 
Further experiments with methyl bromide, first authorized as a 
fnini<rant on Fehrnarv 1."). VXV.). and limited to stock with soil balls 
not in excess of S inches in diameter, showed that all living larvae 
<>f the Japanese hectic are killed in 12-inch pots or soil halls when the 
treatment, dosage, and temperature are properly regulated. Admin- 
istrative instructions were accordingly issued on November 4. en- 
larging the scope of the methyl bromide fumigation procedure t<» 
include hailed nnrserv stock not larger than VI inches in diameter. 
During the remainder of the year this method of fumigation fur- 
nished an outlet for large quantities of nursery and greenhouse stock 
that theretofore could not he satisfactorily treated to eliminate pos- 
sible grub infestation. There is widespread interest among growers 
in tliis simplified method of producing beetle-free stock. 
A new edition of the Shipper's Guide, enlarged to contain the 
cities and towns added to the regulated area with the revision of the 
regulations effective April 5, 1940, was distributed in June. 
In cooperation witli the Division of Insecticide Investigations 704 
soil samples were collected and analyzed from nnrserv plots, heeling-in 
areas, and frames previously treated with lead arsenate. A- a result 
of these analyses, 336.309 square feet were retreated to bring the insec- 
ticidal content of the soil up to the required dosage. In addition, 
461.372 square feet of nursery area received their initial applications 
of lead arsenate. 
Nurseries and orreenhouses fulfilling the requirements for classifi- 
cation under the quarantine regulations decreased during the year 
from 2.514 to 2.075. This decrease was due to stricter requirements 
that were set up for the maintenance of classification. Under former 
regulations it was possible for many establishments to retain their 
classification despite the fact that they rarely asked for certification 
and did little or nothing to produce grub-free stock. They were in 
practically the same status as an unclassified grower so far as their 
ability to ship was concerned. Establishments classified at ihe end 
of the year, numbering 1,642 class 1 or uninfected units and A'-\*2 infested 
or intermediate units, include only those actively engaged in the pro- 
duction and shipment of certified material. Most of those formerly 
classified are obtaining their certification on daily call by an inspector. 
-V- methyl bromide fumigation of stock comes into more general use, 
it is anticipated that the system of classification will further decline, 
w ith shippers depending more and more upon t he fumigation of si i " k 
in the presence of an inspector to take care of their certification 
requirements. 
CERTIFICATION OF FRl ITS, VEGBTAB1 is. AND CUT Flo 7ERS 
In.-pection centers were in operation at 40 points throughout the 
regulated area during the period of adult beetle flight in L989. Bight 
were in Delaware, 6 each in Maryland and New fork, ;» in Virginia, 
l in New Jersey. 8 in Pennsylvania. l } each in Massachusetts and ( )hio. 
and l each in Connecticut, District of Columbia, Maine, and West 
Virginia. 
