The type B warehouses were of similar construction to type A, except 
that there was an open ventilating strip, about 12 inches wide, around all 
lh sides of each building, just below the eaves, This ventilating strip per- 
mitted a movement of air through the warehouse and prevented any appreciable 
build-up of DDVP vapors. 
Type C warehouses were one story high, of brick and hollow tile con- 
struction, with concrete floors and composition roofs. These units were 
quite tight--sufficiently so for fumigation. 
Each floor of the warehouses of types A and B measured 21,2 x 110 x 16 
feet, and contained approximately 25,000 cubic feet. Each storage section 
had a capacity of 3,100 hogsheads stored on their sides, or 3,00 to 3,500 
hogsheads stored on end with the hogsheads racked 3 tiers high. When filled 
to normal capacity with tobacco, each section had 250,000 to 260,000 cubic 
feet of free space. Type C warehouses were 160 x 100 x 18 feet and contained 
288,000 cubic feet. Each section had a capacity of 1,900 hogsheads, and when 
filled to normal capacity had approximately 193,000 cubic feet of free space. 
In each warehouse of types A and B, there was a single aisle next to the 
wall on one side about 10 feet wide and extending the length of the building. 
A single 20-foot-wide aisle extended across the width of each type C ware- 
house, about one-third the length of the building from one end. 
Test Insects 
Cigarette beetles were placed in various locations in each warehouse, 
at heights of 0 to 1h feet above floor level. Screen-wire cages containing 
25 adults each and an indeterminate number of eggs were exposed at these 
locations in the free air space, Test spikes, containing 25 adults or larvae 
in each cell, were driven into hogsheads so that a cell was exposed at depths 
of 1, 3, and 5 inches, and,in some instances, 7 and 9 inches. 
The test insects were insectary-reared, of uniform age and culture, and 
were believed to be as resistant to all insecticides as any natural beetle 
infestation. Adult beetles had emerged within 2) to 48 hours prior to their 
use. Eggs were approximately 2) to 8 hours old at the start of each test. 
Larvae were 2 to 3 weeks old and approximately three-fourths grown. Eggs 
of the cigarette beetle are fragile and cannot readily be counted or handled. 
Short sections of midrib of flue-cured tobacco were split lengthwise, and the 
beetles were allowed to oviposit in these sections of stem. The number of 
eggs per stem could not be determined without injuring some of the eggs, so 
the number of eggs varied in each test. 
Mortality of test insects was recorded 2); to 72 hours after their re- 
moval from the warehouse. All moribund beetles unable to crawl or fly from 
a sheet of paper 8 x 10 inches were arbitrarily considered dead, as such 
