PREVENTIVES. 33 
Directions for fumigating mills and other structures by the hydro- 
cyanic-acid gas process are furnished in Circular Xo. 112 of the 
Bureau of Entomology, and instructions for the use of bisulphid of 
carbon as a fumigant are discussed in Farmers' Bulletin Xo. 145, 
both of which publications may be obtained on application to the 
Secretary of Agriculture. 
While fumigation is not at present practicable in most of the 
'• khans " of the fig-packing companies of Smyrna because of the im- 
possibility of making them sufficiently tight for the purpose, there are 
still chances of ultimate success. For the perfect success of any 
form of fumigation of insects affecting stored products it is highly 
desirable that the buildings or other inclosures in which the material 
is stored be made perfectly air-tight. Under these conditions the 
minimum amount of bisulphid of carbon or other fumigant and the 
minimum exposure can be employed. "Whatever fumigant is used, 
at least 24 hours' exposure is desirable, and in many cases 48 hours — 
particularly if the buildings are not quite air-tight — are necessary, 
especially in comparatively low temperatures. In preparing this 
paper for publication it occurred to the writer that perhaps, every- 
thing considered, the most simple means of fumigating, that is, with 
bisulphid of carbon, would be the best for treatment of fig-packing 
houses. The writer has exchanged opinions on this topic with three 
fig experts and as many entomologists, and they have all agreed that 
this should be a good method if employed by erecting special fumi- 
gating houses, to be made air-tight and placed at some distance, say. 
about 25 yards, from the main building. While it would be better to 
have these buildings constructed of concrete, they can be built of wood 
and lined both inside and out with stucco or cement. This would 
not only render them more nearly air-tight, but would, moreover, 
serve as an additional precaution against fire. It remains to be deter- 
mined what amount of bisulphid of carbon would be the best for use 
in such buildings. 
Efforts have been made to free the figs of " worms " by vacuum 
treatment, but with indifferent success. With layer figs in boxes it is 
not practicable. 
We must, therefore, look for preventives and other more or less 
direct remedies. From the report on this insect made by Mr. E. 
G. Smyth, entomological assistant, engaged in stored-producl insect 
investigations from August to November, 1010. in Smyrna, Turkey 
in Asia, the followng lines of treatment are suggested: 
PREVENTIVES. 
The principal time of infestation is while the figs are on the ground 
drying in the sun, and later, when piled in the iiu* depots (PL IT), 
before shipment to Smyrna from the interior, where the ii<rs are 
C»T0-1°— Bull. 104—11 3 
