F-504082 
Figure 42.—QOak leaves with the blotchy mines 
characteristic of attack by the solitary oak leafminer, 
Cameraria hamaadryadella. 
hosts. The adults and larvae of the two species are similar in appearance, but the 
feeding habits of the larvae differ. Larvae of this species are gregarious, forming 
large brownish-yellow mines, several of which may be found on a single leaf. 
Winter is spent in the pupal stage in leaves on the ground, and there are two or more ~ 
generations per year. Heavy infestations have been reported in oak stands in the 
Central States, causing severe browning and premature dropping of infested leaves 
over large areas. 
Many other species of leafminers attack a wide variety of deciduous trees in 
eastern America. C. hamameliella (Busck) mines the upper surface of witch-hazel 
leaves. It probably occurs wherever witch-hazel grows. The mines are circular or 
somewhat irregular. C. bethunella (Chambers) mines the leaves of oak in Delaware. 
C. aceriella (Clemens), the maple leafminer, produces large white mines in the 
upper sides of red and sugar maple leaves. C. corylisella (Chambers) mines the 
leaves of hazel in Maine. Phyllonorycter salicifoliella (Chambers) occurs through- 
out most of the United States and also in Canada. Its preferred host appears to be 
quaking aspen (8/7). P. crataegella (Clemens) mines the leaves of apple, 
hawthorn, cherry, plum, and quince. Heavily infested trees become ragged and 
scorched in appearance. P. /ucetiella (Clemens), the basswood blotchminer. mines 
the leaves of basswood. The mine Is nearly square. P. trinotella (Braun) mines the 
undersides of the leaves of red and Norway maples. P. robiniella (Clemens) 
produces digitate mines in the upper surfaces of black locust leaves. The aspen 
blotchminer, P. tremuloidiella (Braun), constructs oval mines in the leaves of 
quaking aspen. It is occasionally quite abundant in the Lake States and Maine. 
Chrysaster ostensachenella (Fitch) forms blotch mines in black locust leaves. 
Marmara fasciella (Chambers) is widely distributed, probably occurring 
throughout the range of its host. eastern white pine. Eggs are laid on the bark of 
branches of the host. Young larvae bore through the bark and construct linear mines 
in the inner bark. Winter is spent as a larva in the mine: pupation occurs during late 
130 
