INSECT ENEMIES OF EASTERN FORESTS 49] 
with a crook at the anterior end and with the posterior part some- 
what flattened and lghter in color. The moths issue in July, and 
in general the life cycle is similar to that of other single-brooded 
casebearers. The mines are confined to areas between the principal 
veins of the leaf. C. dimosipennella is an introduced species, first at- 
tracting attention in this country near New York City in 1901. It 
has now been recorded from most of the Northeastern States. The 
favored food plants include Englsh, Scotch, and American elms. 
This insect is primarily a pest of shade and ornamental trees, and 
outbreaks are usually extremely local. The mined parts of the leaves 
quickly turn brown and, if numerous, give the tree an unsightly ap- 
pearance. Control is the same as for C. laricella. 
The moth of the birch casebearer (Coleophora salmani Heinr.) is 
grayish brown, with a wing expanse of about 7%, inch. The larva 
is dark brown, about 34, inch long when full grown, and the last 
four of its five instars are spent as a casebearer (Gillespie, 754). The 
moth was first reported in 1927 near Bar Harbor, Maine, and is now 
known to occur 1n several towns in the eastern part of that State. The 
most favored food plants are paper birch, gray birch, European white 
birch, and speckled alder. Foliage of severely infested trees turns 
brown, presenting a scorched appearance. ‘The moths are present in 
the field from the the middle of June to early in August. The young 
larva spends from 16 to 21 days in a mine before constructing its case. 
It hibernates as a partly grown larva in its case, which is attached to 
some part of the tree. In May the larva resumes feeding, attacking 
buds and tender leaves, and mining as far as it can reach without 
becoming detached from the case. A new case is constructed when 
the old one is outgrown. There is one generation annually. Control 
measures are the same as for C. laricella. 
Famitry GRACILARIIDAE 
The Gracilariidae are the largest of the leaf-miner families and 
includes about half of the lepidopterous species having leaf-mining 
habits. There seems to be a difference of opinion among authors in 
the groupings of some of the species in this family, a few having 
arranged them in 9 genera and others into as many as 17. However, 
by far the greater number of species of Gracilaridae fall within 2 
groups, both of which are placed by some authors under the genus 
Lithocolletis Hbn., while other authorities list them under two genera, 
Cameraria Chapman and Phyllonorycter Hbn. Some 200 North 
American species fall within these two groups. Gracilaria also is a 
large genus, which has some common and widely distributed species 
(Ely, 744, and Needham, Frost, and Tothill, 378). 
The adults are tiny moths often beautifully arrayed in shining scales 
and plumes, and with their more or less lanceolate wings overlaid with 
glistening shades of silver or burnished gold. ‘The larvae are miners, 
at least during the early instars when they are highly specialized sap 
feeders, with the body, head, and mouth parts very flat. Some change 
their form and habits when partly grown, and after the sap-feeding 
period, they feed more upon the tissues or parenchyma of the leaf and 
spin silken threads across the loosened epidermis, forming tentiform 
mines, or skeletonize the leaf from a shelter made by folding over 
a part of the leaf. The larvae of one group continue to be depressed 
