50 BULLETIN 737, U. S. DEPARTMENT OF AGRICULTURE. 
more effective if the sheets of fly paper are pinned so that the surface 
on both the inside and outside of the cylinder is sticky. Traps of 
this type operated in a large tobacco warehouse were under observa- 
tion for some time and were found to destroy large numbers of 
beetles (fig. 13). Another form of trap consists of a large globe, 
such as is used for street lights, placed over a funnel, the lower part 
of the spout of the funnel opening into a cyanid jar in which the 
beetles are killed. An electric-light bulb can be used in the globe, 
or a trap light of the same type can be operated with acetylene or 
other light. Another method of destroying the beetles consists of 
placing shallow pans of 
oil underneath the lights. 
A heavy odorless oil is 
best for this purpose in 
case leaf tobacco, which 
may take up odors of kero- 
sene or other oils, is stored 
near by. The traps fitted 
with cylinders of fly paper 
will perhaps be found best 
adapted to most condi- 
tions: While adults fly 
more readily toward blue 
or blue-violet light than 
toward red or orange, col- 
Fig. 13.—Arrangement for using sticky fly paper in ored light bulbs or colored 
collecting adults of the tobacco beetle in ware- screens cut down the in-— 
houses. - ‘ 
tensity of a source of light. 
Ordinary electric-light bulbs of clear glass of the nitrogen-filled and 
cther types which transmit lhghts rich in rays of short wave length 
have been found well adapted to trapping. 
Sex of beetles collected at light——A sheet of sticky fiy paper which 
had been suspended around an electric hght in a tobacco warehouse 
at Danville, Va., in July, 1911, was examined by Mr.S.E. Crumb. Of 
100 beetles that were removed and dissected, 36 were males and 64 fe- 
‘males. Four females contained, respectively, 2, 2, 17, and 22 mature - 
egos. Seventeen females contained immature eggs, half developed or 
more, as follows: 2, 2, 2, 2, 3, 3, 4, 5, 6, 7, 7, 8, 10, 10, 11, 12, and 36. 
Forty-three females were without eggs. Approximately 32 per cent of 
the females contained eggs and 68 per cent of the females did not. 
COLLECTING AT WINDOWS. 
As the light becomes dim in late afternoon in infested warehouses 
or factories the adult tobacco beetles fiy to the windows, often col- 
lecting in large numbers on the glass and casings. The beetles may 
