144 
seemed to prefei* as food. The beetles were gathered by shaking 
them from the trees at night and picking up those which fell to 
the ground. 
The following table gives the results of these collections made 
at Urbana from Carolina poplar (cottonwood), willow, oak, and 
elm, on twenty-six different nights between j\Iay 14 and June 28, 
1906. 
Comparative Collections of Lachnosterna from Food 
Plants. Urbana, 1906. 
W 
species 
L. implicita 
L. rugosa 
Iv. g-ibbosa 
Iv. f usca 
Iv. hirticula 
ly. inversa 
L(. ilicis 
Iv. tristis 
Total 
Per cent, on each tree 
Poplar 
No. 
1456 
169 
73 
39 
10 
5 
Per 
cent. 
1754 
.50 
.58 
.85 
.72 
.85 
.04 
Willow 
No. 
855 
7 
6 
6 
4 
1 
879 
.25 
Per 
cent. 
.34 
.07 
.13 
.03 
No. 
35 
18 
1 
209 
2 
317 
25 
607 
.18 
Per 
cent. 
.01 
.17 
.02 
.86 
.93 
1.00 
Elm 
No. 
171 
31 
4 
17 
21 
244 
.07 
Per 
cent. 
.07 
.15 
.04 
.07 
.07 
From the foregoing table it will be seen that poplar (cotton- 
wood) was the favorite food, 50 per cent, of the specimens being 
taken from this tree, and that willow follows next with 25 per cent., 
oak with 18 per cent., and elm with 7 per cent., poplar and willow 
together yielding 75 per cent, of the insects. Apple leaves were 
often eaten freely, but no trees were suitably situated for experimen- 
tal field-collecting, and hence no comparative records were made 
which included apple. Apple orchards in the southern part of the 
state have been reported by assistants as sometimes almost stripped 
of their leaves. This was notably so in Jackson county in 1904. 
The pecan- and persimmon-trees of southern Illinois often suffer 
severely by having their foliage eaten by the beetles. 
Certain species of the beetles exhibited marked preferences in 
the choice of food. L. hirticula, ilicis, and tristis had a special liking 
for oak, the last named being taken from no other tree. L. implicita, 
gibbosa, fiisca, and rugosa were most abundant on poplar, rugosa 
seeming to avoid oak and willow. Not enough specimens of L. in- 
versa were taken to warrant conclusions concerning its preferences. 
All of the May-beetles taken at lights in the open fields at night 
in 1906 at Elliott, Ford county, and at Urbana, Champaign county, 
were carefully dissected and the contents of the alimentary canals 
