38 



It seems to be a rather early species, occurring in our southern 

 Illinois collections from March 28 to June 21, in central Illinois from 

 May 2 to July 2, and in northern Illinois from May 16 to July 2. Our 

 data of local abundance in different years are not sufficient to give us 

 any definite clue to the length of its life cycle. 



Altho the preference of this species for oaks, and the well-known 

 greater injury done by white-grubs to crops growing near forest trees, 

 might lead us to give to it an unusual economic consequence, its num- 

 bers are apparently so small that it does not seem likely to do any 

 considerable general injury in any stage. 



PJiyllopliaga ilicis Knoch 



Ilicis is a minor species represented here by only 873 specimens 

 which is less than 1 per cent of the grand total of our collections. It 

 is distributed thruout the state, but seems somewhat the most abun- 

 dant in northern Illinois, where it amounted to nearly 4 percent of 

 our whole number collected. It was, indeed, dominant in the northern 

 section, together with futilis, in 1909, making 27 percent of our 2073 

 northern Illinois specimens for that year to 37 percent of futilis. It 

 is a comparatively late species to appear in spring, our earliest cap- 

 tures coming between May 2 and 26 and our latest between June 16 

 and July 13. 



It is a rather general feeder, with a marked preference, however, 

 for oaks. It is, in fact, the third of our fifteen principal May-beetles 

 in the size of its ratios on oaks, greatly surpassed by tristis and a trifle 

 only by Jiirticula, but very nearly equalled by fervida and fraterna. 

 Its next strongest preference seems to be for elm, in respect to which 

 it is second only to anxia (anxia, 33 percent; ilicis, 17.2 percent). 

 On the other hand, its numbers on poplar and willow, altho relatively 

 small, were too large to be merely accidental. In the four-food-plant 

 series of 1906, 317 out of 351 specimens were from oaks, and 21 from 

 elms. It was eighth in order of our willow beetles and fifth of those 

 from poplar. It was sixth on blackberry, fourth on ash and black 

 walnut, and second on hazel, hawthorn, and rose. Plum, persimmon, 

 linden, honey-locust, gooseberry, birch, and apple each yielded a few, 

 perhaps merely accidental visitors. 



PJiyllopliaga fervida Fabricius 



Fervida, better known under its synonym of arcuata, is a south- 

 ern and central species, only one of our 857 specimens coming from 

 northern Illinois. It was furthermore some fifteen times as numerous 

 in southern Illinois as in central, due account being taken of the dif- 

 ferent numbers of our total collections from these two sections. It 

 was proportionately much more abundant at the south in 1910 than 



