plunger to its open position, and the flutter valve (4) on the upper bellows 
board is forced open, allowing air to escape from the closing bellows. 
The bellows folds return to their original alignment guided by the free- 
swiveling depression knob which is attached by a machine screw (1b). 
The receiving tube (15) is set in a rubber stopper (14), and there is also 
a stopper (10) at the top of the collecting bottle to facilitate removal of 
the insiects: 
The bellows boards, plunger, depression knob, plunger-cylinder 
sleeve, and collecting bottle may be fabricated of sheet and tubular 
plastic, and they can be joined with a suitable plastic cement. The 
flutter valves may be cut from thin rubberized sheeting and glued to 
the bellows boards. The suction pump is made of the two units D and 
F (fig. II), which are joined with the bellows. The bellows may be cut 
from bellows cloth, obtainable from organ sales and service establish- 
ments. 
The aspirator depicted has bellows boards 3 1/2 inches in diameter, 
a plunger 3 1/2 inches long, flutter-valve orifices 3/8 inch in diameter, 
and a plunger-cylinder sleeve 2 inches long. The bellows open 1 1/4 
inches, and this is also the distance from the top of the plunger-cylinder 
sleeve to the bottom of the depressing knob. The connecting tube is 
approximately 2 feet long and the collecting bottle is 7 inches long and 
1 1/4 inches in dtameter. Dimensions of the suction pump may be 
increased, and the size of the collecting bottle decreased for an even 
more powerful aspirator. 
The bellows as described is manually operated; however, it may be 
modified by placing it beneath a foot treadle and thereby freeing one 
hand. Also the collecting bottle may be designed to contain cyanide as 
described by Metcalf (7). Insertion of the connecting tube into the 
stopper (10), drilled to receive it, will eliminate the need for the bottle— 
orifice tube. 
Figure I.--Insect aspirator assembly, elevation view. 
Figure II.--Details of suction pump: A, top view; B, C, D, F, 
elevation views (B, bellows open, C, bellows closed, cross- 
section, D, stripped of plunger-cylinder sleeve and top 
bellows board, F, stripped of bottom bellows board); and 
E, bottom view. 
