Results 



Figure 2 shows the relative response curve obtained in Test Series I. For the 

 energy levels and test conditions of this test series, the peak response occurs in the 

 region between 486 and 546 m/i with a peak response indicated at approximately 515 m/i. 

 Decreased response occurs in the vicinity of 415 m/i and then a secondary peak re- 

 sponse occurs in the near ultraviolet region at about 365 m/i. There was very little 

 response to wavelengths longer than 600 m/i or shorter than 300 m/i. 



Figure 3 shows the relative response curve obtained in Test Series II. This curve 

 is quite similar to the curve obtained in Test Series I and is noteworthy only because 

 it indicates that equally reliable results can be obtained by either of the two test tech- 

 niques when extremely low energy levels are used. 



The results of the intensity studies are presented in graphic form in Figure 4. At 

 the 20 energy level (20 times the level used in the wavelength tests of Series I and II) 

 there was no shift in response characteristics, i.e., 515 m^J remained more attractive 

 than 405 and 365 m/i and 365 m/i was more attractive than 405 m/i. At the 40 level, 

 a shift occurred in the response characteristics and 365 m/i became more attractive 

 than 515 and 405 m/i, with 405 m/i remaining the least attractive. Approximately the 

 same relationship continued to exist at the 80 level with a slight increase noted for 405 

 m/i when compared with 365 m/i. 



Discussion of Results 



The spectral response curves obtained for pink bollworm moths in the ultraviolet 

 and visible regions of the spectrum show that wavelengths in the green region (approxi- 

 mately 515 m/i) are the most attractive under the low energy irradiation conditions em- 

 ployed. The wavelength limits of effectiveness, the peaks of response, and the region 

 of decreased response agree closely ■with certain insect response curves as determined 

 by other workers, particularly Weiss and Stermer. The Angoumois grain moth exhibited 

 very similar response characteristics to those obtained for the pink bollworm moth. 

 The regions of principal interest, 515 m/i, 405 m/i, and 365 m/i, also coincide well 

 ■with similar regions in many of the response curves determined by Weiss. At the low 

 energy levels, the principal response occurs at 515 m/i for the pink bollworm moth, 

 whereas Weiss found this region to be a secondary response peak for many of the 

 insects that he tested. 



Detailed wavelength tests have not been conducted with the pink bollworm at the 

 higher energy levels. However, the results of the intensity tests with equal intensity 

 narrow wavelengths bands centered at 365 m//, 405 m/i, and 515 m/i indicate that the 

 response peaks of 365 m/i and 515 m/i become equal at some energy level between 

 20 and 40 and that above this level the 365 m/i region is the principal response region 

 with 515 m/i becoming less attractive. Recent work with the same wavelength bands at 

 even higher energy levels (up to the 320 level, i.e., 16 times greater than 20 level) 

 indicates that this relationship between wavelengths continues to exist at these higher 

 levels. Thus, from the results of these tests, it appears that equal intensity wavelength 

 tests at higher energy levels would yield a response curve for the pink bollworm moth 

 nearly identical to those obtainedby Stermer for the Indian-meal moth (and the Angoumois 

 grain moth at high-energy levels.) Such curves would also correspond closely to the 

 majority of the response curves determined by Weiss. 



Sex determinations were made of all moths used in these tests. The response 

 curve for the male and female moths was nearly identical. 



No attempt will be made to analyze or explain the shift in peak response from the 

 green at low energy levels to the near ultraviolet at increased energy levels. However, 



18 



