31 



next largest ratio of 9.2 percent ; and that in the ratio for implicita, 

 oak is represented by 1.6 percent and hickory and blackberry by less 

 than 1 percent. The principal food resorts of implicita, on the other 

 hand, were apple, poplar, and willow, represented by nearly equal 

 ratios and frequented by 92.6 percent of our specimens. The corre- 

 sponding ratios for Mrticula were poplar, 2.4 percent, willow, 2.9 

 percent, and apple, less than 1. It is evident that these species, seem- 

 ingly so closely associated over our whole territory, have a different 

 ecological distribution, the one frequenting oak and hickory uplands 

 primarily, and the other, cottonwood and willow lowlands. 



It seems quite possible that this destructive May-beetle, the sec- 

 ond species in the state for abundance, might be effectively poisoned 

 by spraying, in May, poplar and willow-trees, if these were so distrib- 

 uted and grown over one's premises as to attract the beetles to them 

 and, by regular replacement of old trees by young ones, kept small 

 enough to be readily reached with a convenient spraying equipment. 



PJiyllopliaga fusca Froelich 



Fusca is a distinctly northern species, 4356 of our 11,800 speci- 

 mens collected coming from northern Illinois, 7442 from central Illi- 

 nois, and but 2 from the southern part of the state, at Carbondale and 

 Anna. Within its area it is one of the more abundant species, giving 

 us 12.5 percent of the total number of all our collections from the 

 northern two thirds of the state. It is one of our earliest May-beetles, 

 appearing in 1910 as early as April 9 in central Illinois, and in north- 

 ern Illinois April 14. It commonly continues numerous to the middle 

 of July, its period of adult activity thus covering some three months. 



Our 1907 collections were made chiefly in Champaign county, and 

 in McHenry county at Algonquin. In northern Illinois there was no 

 indication that 1907 was a fusca year in the districts represented by 

 these points. In 1908, however, it was the leading species at Aurora, 

 altho futilis crowded it closely for the dominant position. In Cook 

 county its numbers, altho small, were nearly double those of futilis — 

 the next most numerous species in our collections of that year. In 

 1910 it was subdominant at Aurora and in Cook county, being second 

 in both places to anxia. In central Illinois (Urbana and Galesburg) 

 it was also subdominant, second only to Mrticula, which was, however, 

 more than six times as abundant. In 1913 it was dominant at Aurora 

 and Rockford, and subdominant in Cook county, where it was ex- 

 ceeded by anxia and futilis. Its predominance in Cook county and 

 at Aurora in 1910 and again in 1913 indicates a three-year cycle for 

 this species. It is a rather indiscriminate feeder, found by us at 

 various times in large numbers on apple, ash, blackberry, poplar, and 

 walnut. In respect to the ratios of its numbers on its different food- 

 plants, it stood first among our species on ash, walnut, hazel, and 



