COLLECTIONS FOR TAXONOMIC PURPOSES 



Diurnal species of insects are seldom taken in light traps, since they do not respond 

 to forms of artificial light. However, afew species of butterflies belonging to the families 

 Pieridae, Lycaenidae, and Nymphalidae are occasionally taken, particularly during 

 migration periods when the .population level is particularly high. Whether the lights di- 

 rectly attract them, or they fall into the trap by chance has not been determined. Certain 

 species of nocturnal insects may occur abundantly, but seldom are attracted to lights. 

 There may be a sexual difference in response to light within a species, as often the males 

 are taken in abundance, but the females rarely or vice versa. However, Robinson (1952) 

 considers that as far as he was able to discover, the sexes, if they are night-flying, are 

 equally susceptible to diversion to bright lights and any differentiation, in representa- 

 tive catches, is due to the fact that the two sexes fly in different areas. 



As previously mentioned, certain species of moths may seldom if ever be seen or 

 collected without the use of light traps. While using a black-light trap in Rock Creek 

 Canyon near Colorado Springs, Colo., in August 1953, the writer took 15 specimens of the 

 supposedly rare arctiid moth, "The Painted Arachnis", ( Arachnis picta Packard) in one 

 night. A veteran collector of Lepidoptera, the late J. F. May, remarked in great amaze- 

 ment at the time that he had neither collected nor seen a specimen of this species in 40 

 years. 



Many phalaenid moths, particularly Catocala spp., some of which are extremely 

 rare or difficult to collect, often may be taken in numbers in the traps. This may be 

 said of genera and species of other orders as well. On a trip to southeastern Mexico 

 in company of Dr. F. C. Bishopp, a portable black-light trap was used on several occa- 

 sions, and a number of moths were taken which would otherwise not have been collected. 



Russian entomologists apparently have begun to realize the importance of the use of 

 light traps as indicated in an article by G. A. Mazokhin-Por shniakov (1956), in which he 

 states: "Light traps with a mercury vapor lamp can be utilized not only for the sake of 

 faunistic collections of insects, but also for the study of dynamics of flight of injurious 

 species which is extremely important to applied entomology." He further commented 

 that the use of mercury vapor lamps lead to evidence of new possibilities for the study 

 of entomo-faunas by the utilization of this source of light. It was interesting to find that 

 this article refers to work done on light traps by Hollingsworth and Glick in 1954. 



Some English entomologists have predicted that the excessive use of light traps may 

 cause a rapid disappearance of many rare and fine species in Great Britain, including 

 Catocala fraxini , which collectors trapped by tens and hundreds of specimens every 

 evening. 



DETECTION FOR INSECT PESTS 



An important use of light traps is to determine the presence of insect pests in an 

 area, and to record throughout the year their population changes. 



Since possibly the greater percentage of the injurious species of insects are 

 crepuscular or nocturnal in habit, much valuable information can be obtained from rec- 

 ords of various important economic insects taken in the traps, particularly before they 

 are known to occur in an area, or before an infestation is noted. 



A significant new use for the fluorescent black-light was reported by Haruro Tashiro 

 (News Release 3266-58) in the attraction and capture of the grassland-destroying 

 European chafer beetle. This was considered a definite breakthrough in the search for 

 an effective means of determining the extent of the infestation and the need to establish 



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