11 



wrung out, slightly dried, and placed over the frame and held in place 

 by nailing the diagonals to the frame above the cloth. A gallon of 

 linseed oil is sufficient for rendering four covers of the size above 

 specified sufficient!}^ air-tight for this method. 



The number of frames for use depends upon the degree of infesta- 

 tion and the rapiditj^ of the operators. Ordinarily about 10 frames 

 are sufficient for one man's attention. 



Method of application. — The frame is placed over the infested plant. 

 One sheet of the fumigating preparation is torn into from two to four 

 or more equal parts (according to directions on the package or j^s 

 experience may decide) and each part is put in a tin fruit can under 

 the frame near a corner and then ignited. The cans are perforated 

 at the bottom by driving a large nail in at the side. It is well to use a 

 long taper or fuse for lighting the f umigant. afi'ording the more active 

 beneficial insects time to escape from under the cover before the tobacco 

 fumes are given ofi". Earth is then heaped on the border of the' cloth 

 on the ground to prevent the escape of the smoke. The frame should 

 remain in position ten or fifteen minutes, or longer if preferred. Each 

 operator should have enough frames to handle so that each frame in 

 succession ma}^ remain on a vine during the time mentioned. 

 . In localities where the aphis is most injurious local merchants who 

 deal in insecticides should be informed of the fact and requested to 

 keep a supply of fumigating preparation always in stock. 



The best time for fumigating is when there is no wind and the vines 

 are damp. In moderately dry weather, however, good results may 

 be ol:>tained. 



Cautiox. — Care should be exercised not to allow the dry fumigant 

 to ignite. It should smolder only. Vines should not be disarranged 

 except where the}' protrude a few inches beneath the cover. The 

 leaves should not touch the top of the cover. 



Yariations of the fumigating frame. — The frame described above 

 has been used in the fumigation of young plants in southern Texas. 

 The size and make-up of the frames may be altered or improved by the 

 individual grower to adapt them to the size of the vines and the nature 

 of the plant to be fumigated. Farther north than Texas manifestation 

 of injury is not usually observable until the plants have made consid- 

 erably larger growth, and a larger frame, say about a foot high, will 

 be found more desirable for general use. Unbleached cotton of com- 

 pact mesh, at 10 cents a yard, answered as well as the oiled "muslin" 

 in experiments conducted by the writer, and there is a saving of time 

 in its use. Moreover, it does not collect dirt nor soil the clothing and 

 other objects with which it comes in contact. 



For the treatment of plants other than cucurbits, such as cabbage 

 aflected by the cabbage aphis, eggplant, tomatoes, and other truck 

 Mr. Sanborn advises a hood, using a frame made of two wires bent in 

 a semicircle. Strong barrel hoops may be substituted, and the cover 

 tacked to them at the top where they cross and at the bottom of the 



