. Bulletin of the Department of Agriculture. Agriculture; Agriculture. 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
. Bulletin of the Department of Agriculture. Agriculture; Agriculture. 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 acetjdene 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 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 mere readily toward blue or blue-violet light than toward red or orange, col- ored light bulbs or colored screens cut down the in- tensity of a source of light. Ordinary electric-light bulbs of clear glass of the nitrogen-filled and other types which transmit lights rich in rays of short wave length have been found well adapted to trapping. Sex of beetles collected at light.—A sheet of sticky fly paper which had been suspended around an electric light 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 eggs. 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
Size: 1684px × 1483px
Photo credit: © Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauth, bookcentury1900, bookdecade1910, booksubjectagriculture
