INSECT ENEMIES OF EASTERN FORESTS 161 
ficially resemble those of the May beetles, but the body segments are 
more platelike dorsally and not transversely folded, the oula is more 
distinct, and the galea two-jointed. 
An undetermined species of Byrrhus is common in the Lake States, 
in sandy soil, and occasionally causes injury to seedlings. 
FOREST LEAF CHAFERS AND WHITE GRUBS 
LAMELLICORNIA 
By LEE EK. YEAGER 
The lamellicorn beetles are characterized by the peculiar terminal 
structure of each antenna, which is a club composed of three, and in 
one genus six or seven, leaflike plates. The lamellicorns are here 
treated under four families, namely Trogidae, Passalidae, Lucanidae, 
and Scarabaeidae. Of these families the Scarabaeidae is by far the 
largest and most important, as it includes a large number of injurious 
species. This family, the Scarabaeidae, consists of two general sub- 
divisions, the lamellicorn scavengers and the lamellicorn leaf chafers, 
of which only the latter need be treated here. The Passalidae and 
Lucanidae are of interest because of their habit of living in decayed 
wood, in the eastern forests, being especially associated with hard- 
woods. The Trogidae are known as skin beetles, and as they char- 
acteristically occur on dead animal material, they will not be further 
considered. 
INJURY IN NURSERIES AND PLANTATIONS 
From the viewpoint of the forester, damage by lamellicorn beetles 
and larvae must be considered both in nurseries and forest plantations. 
Each of these two conditions presents its own problems, but in general 
the control of injury to plantations, because of the absence of intensive 
cultivation and the large areas involved, offers the greater difficulty. 
Although the chief damage i is caused by the feeding of the grubs on 
seedling roots, the adults i injure trees by eating the foliage. Serious 
defoliation may result when beetles of the genus Phyllo phaga concen- 
trate on hardwood trees in large numbers. Two other gener: 
Macrodactylus and Pachystethus, may appreciably defoliate oaks and 
pines, respectively, and other genera may occasionally be injurious. In 
comparison with the work of other defoliators, lamellicorn defoliation 
is more or less negligible, although in some instances hardwoods may be 
completely stripped and pines heavily defohated. 
Seedling mortality traceable to erub feeding has occurred in nur- 
series and } plantations throughout the Eastern States. The percentage 
of injury runs from near zero to as high as 90 percent. The higher 
percentage of injury occurs on certain types of trees on the Marquette 
National Forest, in Upper Michigan. Such mortality, however, is 
unusual. Losses of from 5 to 20 percent of the stock in nurseries and 
young plantations is far more common than higher losses. 
From the studies of the last several years a few generalizations can 
now be drawn in regard to grub injury and control. ‘The first of these 
is that serious injury in the East appears to be caused by only a few 
out of the 30-odd genera known to occur. These injurious groups are 
Phyllophaga, Ochrosidia, Polyphylla, Diplotaxis, and Serica. Sev- 
eral other genera, such as Auwtoserica, Popillia, Anomala, and Cotinis, 
may be injurious in nurseries, but they are not often of much im- 
portance. Also, Diplotavis and Serica larvae seem to be relatively 
