Light traps were described in the literature at least 5 years before Edison's inven- 

 tion of the incandescent electric lamp with carbon filament in 1879. Because of this early 

 development of light traps using light sources other than the electric lamp and probably 

 because of lack of available electric service, light traps using electric lamps are not 

 mentioned in the literature until after the start of the 20th century. Development of the 

 tungsten-filament lamp in 1907 was followed almost immediately by specially designed 

 light traps using it as the attractant. 



For this discussion, light trap designs will be considered for two purposes: (1) Sur- 

 vey of insect emergence and abundance and (2) control of economic insects. 



Traps designed particularly for survey purposes require selection of the attractant, 

 positioning it in the trap, and design of the collecting device. The latter may be assumed 

 to consist of two parts: (1) The lamp housing consisting of the lamp support, access 

 opening or funnel to the killing or collecting chamber and, if used, trap roof, baffles and 

 other accessories, and (2) the killing or collecting chamber. 



Electric lamps are now generally used as the attractant, but selection of the specific 

 lamp for a certain insect species still requires experimental determination in many 

 cases. Several of the lamps, previously mentioned, have been available for the first time 

 since World War II. Limited information is available on their attraction to individual 

 species. Available information on wavelength and intensity of radiation in relation to 

 attracting certain insects will be presented by two of my colleagues later on this program. 



Capturing devices for light traps vary in design because of differences in flight 

 habits of various insects. Baffles are desirable in a trap for strong-flying insects such 

 as the hornworm moths, since they will strike the baffles and drop into the trap. With 

 light flyers, such as mosquitoes, pink bollworm moths, and cigarette beetles, an electric 

 fan may be desirable to draw the insects into the trap. 



The killing or collecting chamber may be a screw-top glass jar of appropriate size, 

 a quickly detachable metal container, or a screened bag or box. Use of the last is 

 normally restricted to situations where live specimens are desired. Various poisons 

 are used in the jar or container to quickly kill the insects. A discussion of the merits 

 and disadvantages of each would be too lengthy to warrant inclusion here. 



Several traps for attracting specific insects have been developed. The New Jersey 

 mosquito trap was developed in approximately its present form in 1933. There were 205 

 of a modified type of this trap in use in California for mosquito survey work in 1957. 

 The attractant is a 25-watt, inside-frosted, white, incandescent lamp. A 3/8-inch 

 galvanized screen over the mouth of the tube prevents entry of large insects but permits 

 mosquitoes and other small insects to enter. An electric fan just below this screen 

 circulates air downward through a bronze screen wire cone at a velocity of 850 feet per 

 minute. Insects are collected in the jar at the bottom. 



A similar trap has been built according to Defense Department specifications for 

 survey of mosquito populations. On the front of the black box is an automatic time 

 switch. 



Other survey traps were developed between 1928 and 1942 for certain insects in- 

 cluding gnats, European corn borers, Noctuidae, fleas, Asiatic garden beetles, cigarette 

 beetles, and leafhoppers. All of these traps use incandescent tungsten-filament lamps 

 as attractants. But some studies are being made by the Stored Products Insects Branch, 

 AMS, to determine the response of cigarette beetles to near ultraviolet radiation. A 

 public patent was issued to W. O. Reed, USDA, on the original cigarette beetle trap. 



Field tests of high-wattage mercury vapor lamps for European corn borer attraction 

 were made in cooperation with the Indiana Station in 1949. A special cylindrical trap of 

 16-inch diameter and height, with 6- by 12-inchfront opening was designed for this study. 

 The design was eventually discarded because a smaller lamp and horizontal mounting 

 appeared to be more suitable for survey work. 



