143 
tained by making collections from the food plants at night that they 
evidently have comparatively little real value. For example, leaves 
of Osage orange were offered, without other food, to fiisca, invcrsa, 
implicita, ilicis, rugosa, and tristis. They were eaten moderately 
by implicita and rugosa, and slightly by fusca, invcrsa, and ilicis, 
but were constantly refused by tristis. On the other hand, extensive 
observations made in the field have given us no instance of actual 
feeding on this plant in the open air by any of our species, although 
it is everywhere in common use as a hedge plant. 
The following table shows the different kinds of food oft'ered to 
Lachnosterna beetles in breeding-cages in 1904 and 1905, and data 
as to the readiness with which each sort of leaf was eaten when 
but one kind of food was placed in the cage. 
Results of Feeding Experiments with 
May-beetles (Lachnosterna). 

.0 

u 
U 
a 

3 
2 
3 

u 
1—4 
.2 
a 
u 
0) 
> 
< 
Carolina Poplar, 
(Pofiiliis moiiilifera) .. 
Willow '. 
1 
3 
1 

3 
3 
2 
2 
2 
2 


2 
1 
1 
1 
1 
2 
2 
3 
3 
3 
3 
3 
3 
3 
1 
1 
1 
1 
2 
1 
2 
2 
3 
2 
2 
2 
3 
1 


1 

2 
2 
2 
3 
3 
2 
2 
3 
3 
3 
1 
3 
1 
2 
1 
1 
2 
1 
3 
3 
3 
2 
3 
1 
2 
1 
3 
3 
3 
3 
3 
2 
2 
1 
1 

1 
1 
1 
2 
1 
3 
3 
1 








2.62 
2.50 
Oak 
2.50 
Elm 
2.62 
Apple 
2.37 
Box-elder 
1.75 
Plum 
1.50 
Peach 
.71 
White Ash 
1.57 
Tulip tree, 
{Liriodendron^ . . 
Hedg'e 
.57 
1.40 
Lilac 
1.33 
Cherry 
1. 
Corn 
1.50 
Grass 
1.60 
l=slig'htly eaten, 2 =nioderately eaten, 3 = freel.y eaten, = refused to eat, - = not offered. 
Ah attempt was also made to test the general food preferences 
of each species by offering several different kinds of food in the cage 
at once. Under these conditions, L. fusca, inversa, and implicita 
ate most freely of Carolina poplar and willow ; L. ilicis and hirticula 
ate most freely of oak, but freely, also, of Carolina poplar and elm ; 
and L. tristis ate only oak when that was present. L. rugosa se- 
lected poplar and elm, and L. gibbosa, oak and elm. 
In 1906, at Urbana, extensive collections were made with equal 
care from each of the four different kinds of trees which May-beetles 
