29 



hibernating beetles which had transformed the year before, but those 

 taken in July were most likely newly transformed from pupae of the 

 year, not to come- up from the ground until the following spring. In 

 northern Illinois, where but few collections were made behind the 

 plow, one of these beetles was found in the ground April 22, and in 

 southern Illinois nine were taken on the same date. 



Quite consistently with its general abundance, liirticula is a rather 

 general feeder. Among the trees and shrubs on which we have found 

 it present in large numbers at night are oak, blackberry, mountain 

 ash, cherry, hickory, black walnut, persimmon, and birch — abundantly 

 in the order named — , and, in smaller but still considerable numbers, 

 gooseberry, linden, poplar, elm, and willow. It has also occurred 

 occasionally, and perhaps only accidentally, on apple, plum, box- 

 elder, ash, and maple. In a systematic special collection made at 

 Urbana May 14 to June 28, 1906, from four food plants only — that 

 is, oak, elm, poplar, and willow — 342 specimens of liirticula were 

 taken, of which 309 were from oak. An examination of my table on 

 page 60 will show that this species had a larger percentage of its 

 numbers on oaks than twelve of the fourteen other species of that 

 table, and a smaller percentage than two. It was, in other words, 

 third in the order of apparent preference for the oak ; and it w T as also 

 third on the list of hickory species and on blackberry — facts which 

 bring it clearly into the oak-hickory group of May-beetles. On the 

 other hand, it is sixth on poplar, persimmon, and elm, and thirteenth 

 on willow. Its ratios on the other plants of our list are too small to 

 serve as indications of its choice of foods. The trees and shrubs which 

 it seems to frequent by preference are so numerous and so generally 

 distributed in central Illinois that it can scarcely need to go far for 

 food from any field in which it may originate, and the effort to poison 

 it by spraying its food plants seems therefore practically hopeless. 

 It is, on the whole, one of the most dangerous species in the state. 



PJiyllopJiaga implicita Horn 



Sixteen thousand nine hundred and eighty specimens of implicita 

 are in our Illinois collections — nearly 15 percent of our six years' 

 total for the May-beetle genus. This is next to the most abundant 

 species in the state, surpassed only by liirticula. Like that species, it 

 is relatively poorly represented in the northern part of the state, 

 where it made 4.5 percent of our total number of May-beetles for the 

 period. In central Illinois, on the other hand, it made 55.5 percent, 

 and in southern Illinois, about 10 percent, of those collected in these 

 sections. Taken year by year in central and southern Illinois, w r e 

 find this species making, in 1906, 72.2 percent, and in 1907, 36.6 per- 

 cent of the total of our central Illinois collections- — virtually all in 

 both years from Champaign county; in 1908, 6.1 percent; in 1909, 



