focal length Bausch and Lomb grating monochromator with appropriate blocking filters 

 and slits set at 0.5 mm. (this slit width gave a half-power bandwidth of radiation of 3.3 

 mju) was used on the opposite end of the tunnel to provide the test wavelengths. The 

 radiation from these sources was presented to the insects by means of 3j" x 3j" quartz 

 diffusers mounted at each end of the tunnel. Stray light was eliminated by means of sheet 

 metal cones mounted between the diffusing plates and the sources. 



Preliminary tests were conducted to determine testing techniques that would give 

 reproducible results with a minimum of variation between tests. Use of a very low 

 energy level was found to be desirable (probably due to dimensions of the test tunnel). 

 The absolute value of this arbitrarily selected energy level was not determined, but 

 measurement and calibration techniques permitted equalizing of the energy levels used 

 at the various wavelengths. This equalization was based on the known spectral response 

 characteristics of the multiplier phototube. It was also found that the moths were much 

 more active during the afternoon and evening periods so all tests were initiated after 

 1100 hours. All tests were conducted with moths that had emerged from infested seed 

 cotton some 3 to 4 days earlier. A minimum of 3 tests was conducted for each wave- 

 length compared. This involved a total of 92 test runs and a total of 5,116 moths for 

 the complete test series. 



The following basic procedure was used for all tests: 



1. A pre -selected energy level at 365.4 m/i, as determined by the instrumentation, 

 was applied to the quartz diffusing plate at one end of the tunnel. 



2. The wavelength band to be used for comparison was applied at the opposite end 

 of the tunnel at the same energy level. 



3. Pink bollworm moths in groups of 10 to 152 (an average of 54 per test) intro- 

 duced into the short center section of the tunnel were held in total darkness for a period 

 of 5 minutes. 



4. At the end of the 5 -minute dark conditioning period, the tunnel partitions were 

 removed, exposing the moths to the 365.4 radiation from one end of the tunnel and the 

 test wavelength at the opposite end. 



5. After 15 minutes' exposure to the two energy sources, partitions were inserted 

 into the tunnel, dividing it into 5 compartments. 



6. Heat was then applied to the tunnel by means of infrared drying lamps in order 

 to kill the moths. 



7. The numbers of moths of each sex in each of the 5 compartments were then 

 determined. 



8. An analysis of results was based on the numbers of moths found in the com- 

 partments adjacent to the ends of the tunnel. 



Test Series II : In this series of tests, 10 wavelengths were selected for determination 

 of comparative responses. Each wavelength was compared with every other wavelength, 

 and two replications were made with each combination. This test procedure was recom- 

 mended by statisticians of the Biometrical Services, ARS, who felt that such a test 

 procedure would give more reliable data for analysis of response characteristics. 



16 



