22 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 82 



tine and Control Administration made practical use of this idea by 

 installing bait traps along the edges of the Japanese-beetle infested 

 zones. So far little has been published on this particular phase of the 

 work. According to the report of Secretary of Agriculture Hyde (27) 

 the use of beetle traps at Baltimore and Washington, and in Alexan- 

 dria County, Virginia, has resulted in the collection of great numbers 

 of beetles. The possibility of substantial control at such isolated points 

 by this method will thus be given. It has already been demonstrated 

 that enormous quantities of beetles can be collected by trapping. In 

 fact, on a single property in Pennsylvania (not New Jersey as re- 

 ported) nearly a ton of beetles were thus collected in 1929. In the 

 heavily infested areas, such trapping is of little value unless the em- 

 ployment of this method is general. Van Leeuwen (88) states that 

 25,000 of the Government standard traps, which he illustrates, were 

 used by the Plant Quarantine and Control Administration during 

 1929 in its scouting work to determine the presence of beetles. Rex 

 (65) illustrates and briefly discusses these traps and gives the bait 

 formula recommended by the Japanese Beetle Laboratory in New 

 Jersey. Van Leeuwen and Metzger (89) give the very latest informa- 

 tion about traps for the Japanese beetle. They recommend the follow- 

 ing formula for one baiting of a standard trap. 



Geraniol (at least 58 per cent pure) 15 grams (4 teaspoonfuls) 



Eugenol (U. S. P.) 1.5 grams (^ teaspoonful) 



Bran 75 grams (li rups) 



Water 13 cc. ( i tablespoonful) 



Molasses 39 cc. (2^ tablespoonfuls) 



Glycerine (C. P) 6 cc. (i^ teaspoonfuls) 



Figure 4 was drawn by the present writer and illustrates the 

 various parts of one of the standard traps. 



At this place a few more remarks concerning the attractiveness 

 of geraniol should be made. The effort is usually made to correlate 

 attractive odors either with the food or op^Msite sex of an animal ; 

 but in some cases it is questionable whether food, or sex, or some 

 unknown factor, is involved. For example, why should the banana- 

 like odor of amyl acetate attract grasshoppers, or certain beetles? 

 And why does the odor from the catnip plant attract members of 

 the cat family? In regard to the attractive power of geraniol, a food 

 odor is probably involved, although we know little about it. Smith 

 (76, p. 59) and Smith and Hadley (79, p. 58) in two of their earlier 

 reports remark that several of the essential oils were found to be 

 highly attractive to the Japanese beetle, and that on studying these 

 oils, it was discovered that one of the higher alcohols, geraniol, was 



