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 and feed together, 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 Lithocolletis attack a wide variety of 
deciduous trees in eastern America. L. salicifoliella Chambers 
occurs in Canada and probably throughout most of the United 
States. Its preferred host appears to be trembling aspen. Martin 
(502) discussed its biology in Canada. L. crataegella Clem. mines 
the leaves of apple, hawthorn, wild cherry, plum, and quince. 
Heavily infested trees become ragged and scorched in appearance. 
L. lucetiella Clem. mines the leaves of basswood. The mine is 
nearly square. L. hamameliella Buseck mines the upper surface 
of witch hazel leaves. It probably occurs wherever witch hazel 
grows. The mines are circular or somewhat irregular. L. bethu- 
nella Chamb. mines the leaves of oak in Delaware. L. trinotella 
Braun mines the undersides of the leaves of red and Norway 
maples; L. aceriella Clem. produces large white mines in the 
upper sides of red and sugar maple leaves. L. robiniella Clem. 
produces digitate mines in the upper surfaces of black locust 
leaves. L. ostensackenella Fitch forms blotch mines in black locust 
leaves. The aspen blotch miner, L. tremuloidiella Braun, con- 
F-504082 
FIGURE 162.—Oak leaves with the blotchy mines characteristic of attack by 
the solitary oak leaf miner, Lithocolletis hamadryadella. 
407 
