. -107- 
cherry, "butternut, hazel, hickory, "basswood, and ironwood supplying 22 . 56 , 
21,95* 14,58, 12 . 32 , 5 - 62 , and 4.60 percent of the total, respectively, 
and collectively Si . 63 percent of the total for this species. 
P., fusca \ 7 as collected from 22 kinds of host plants. Butternut, 
wild plum, cultivated cherry, hickory, ironwood, and dogwood supplied 
25 - 33 * 19*30» 17*75* 14.88, l4.00, and 5*12 percent of the total, re- 
spectively, and together 96. 38 percent of the total for this species. 
P. "balia was found on 13 kinds of host plants. Hickory, "butternut, 
hazel, red oak (group), wild plum, and ironwood supplied 35*82, 15*42, 
13*43» 7*46, 6.97* and 6.47 percent of the total, respectively, and to- 
gether these 6 hosts supplied 85*57 percent of the total for this species. 
» 
P. ilicis was collected from l 6 kinds of plants. .Hazel, "butternut, 
hickory, wild plum, and ironwood supplied 33*33* 24.34, 11.64, 6 . 88 , and 
4.23 percent of the total, respectively, and together 80.42 percent of the 
total for this species. The various hosts of the less abundant species 
are given in table 3 * 
Plight Habits of the Beetles 
In general, observations on the flight habits of June beetles in 
1938 were in agreement with those made in previous years. P. fusca and 
P. tristis emerged earlier in the season and at lower temperatures than 
did the others, but P, tristis was rare and no cl os ’6 check could be kept 
on the conditions that governed its emergence. In the case of P. fusca , 
however, comparisons were made of its seasonal and temperature reactions 
with several other common spocies. P. tristis is not considered in the 
following discussion, but its relative population is indicated on some of 
the charts. 
P. fusca , in addition to issuing earliest in the season, was most 
numerous for some weeks after its initial emergence, whether temperatures 
were low or high. At Dane on the night of April 27* when the air tem- 
perature was 71 ° F* and the soil temperature just below the surface 67 °, 
the beetles caught were almost exclusively P. fusca and the flight was of 
fair size. Essentially the same conditions prevailed on May 2, but P. 
rugosa and F. balia were then appearing. 
Later in the season the effect of temperature on the emergence of 
different species was more clearly shown. In some areas, by May 2, 
species other than P. fusca predominated when the temperatures were high 
enough, but when temperatures were below approximately 55 ° F. the propor- 
tion of P. fusca beetles increased. At Bane on May 23, when the air 
temperature was 51° and the soil temperature 59 ° the beetles were mostly 
P. fusca ; at Leeds on May 13 , when the air temperature was 48°, the beetles 
were exclusively P. fusca ; but at Bane on June 2, with the air temperature 
at 64° f both P. rugosa and P. hirticula were about five times as numerous 
as P. fusca ; and at Leeds on June 13 , with the air temperature at 62°, 
P. rugosa again was about five times as numerous as P. fusca. 
