1907.} 



White-grubs and May-beetles. 



455 



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 fusca, inversa, 

 implicita, ilicis, rugosa, and tristis. They were eaten moderately 

 by implicita and rugosa, and slightly by fusca, inversa, 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 offered 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 (Lachnostekna). 



l=slielitly eaten, 2 =iiioderately eaten, 3 = freely eaten, = refused to eat, - = not offered. 



An 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 



