For example, infrared (heat region) lamps with nichrome wire filament in quartz 

 glass bulbs and luminescent plates are available. The former radiates heat with little 

 or no visible light and the latter radiates energy nearly all of which is between the 

 ultraviolet and infrared with uniform brightness over the entire surface of almost any 

 area desired. The luminescent plates are available in many colors. Neither of these 

 devices had been used in any of the research reported by the prepared papers. 



It was brought out in the discussion that more research was needed on the relative 

 importance of spectral distribution versus total energy output of light sources as well as 

 the relative effectiveness of a point source as opposed to a larger area with the same 

 total energy output. 



The need for further study of the response of insects to various types of flashing or 

 flickering was emphasized. Although limited research on this phase was reported, it 

 was pointed out that such light sources have many variables, most of which have been 

 inadequately studied. 



It was also suggested that more intensive research was needed on the response of 

 insects to infrared (heat) radiation and that the complete spectrum of sound waves also 

 should be thoroughly investigated. 



The need for intensive basic studies of the physics, chemistry, and biology of insect 

 response to stimuli was especially emphasized. It was pointed out that most of the re- 

 search tools needed for such investigations are available if the needed resources are 

 allocated and the necessary effort made. For example, in such studies illumination 

 should be in actual physical quantities rather than footcandles or candlepower based on 

 the response of the human eye. There is need to determine whether the insect's eye is 

 the significant receptor, and whether the angle of the cells of the insect's compound eye 

 is a significant factor in determining the wavelength of radiation to which it responds. 



During this part of the discussion it was suggested that the secondary response of 

 some insects to ultraviolet radiation at 3650 Angstrom units in addition to the major 

 response to green at 5200 Angstrom units might be the result of fluorescence of the 

 eyes of insects by the ultraviolet radiation. 



It was also emphasized that basic study of insect response to induced light should 

 not be limited to motor response or movement, and that diapause, photoperiodism, 

 growth, mating, and other physiological changes should be investigated. 



There was considerable discussion on the effects of location and environment of a 

 light trap on its performance. It was pointed out that two apparently similar locations 

 sometimes gave very different results. The great importance of weather conditions was 

 emphasized. One participant reported that in studying the effect of weather on insect 

 activity men were recording 14 variables including air temperature, soil temperature, 

 wind direction and velocity, barometric pressure, relative humidity, rain, sunshine, 

 and atmospheric electricity. There appears to be evidence that atmospheric electricity 

 and ionization are not being adequately considered. 



It was pointed out that though many canning companies are using the light trap as a 

 tool for survey to guide in the application of other control methods, much research is 

 needed to determine the spacing and number of traps needed, to evaluate the significance 

 of catches of different insects und^r different conditions and to develop and improve 

 traps needed for different uses. 



It was further pointed out that insect surveys, to be most effective, should start early 

 in the season in order to record the initiation of insect activities and follow population 

 trends. In addition, the small catches of insects obtained when populations are low permit 

 satisfactory identification and analysis. Later when insect populations are high, the 

 number of insects caught (frequently of nonsignificant species) may make sorting for 

 identification very difficult. 



The importance of any insect control method which does not require a toxic chemical 

 was emphasized as justifying continued investigation of light and sound as control or 

 supplementary control tools. 



54 



