LIBRARY

448 COLLEGE ENTOMOLOGY
Ocelli generally present in family as now restricted. Proboscis well developed.
Falpi normal or short; labial paJpi upturned with segment III at right angles
to II and blunt or fusiform; maxillary palpi three-segmented, porrect, reduced,
or absent. Wings without aculere or microtrichia; fore wings narrow and sometimes
drawn out into a long point and without stigma; hind wings narrower.
The larva; are of two types, the young and the older forms. The young have
the head flat, ocellame very small and variable in number, being reduced even
to just a single pair; rarely apodous; prolegs vestigial or absent when thoracic
legs are present, always absent on abdominal segment VI. Crochets uni- or
biordinaI. Mature caterpillars are cylindrical, with normal head, minute body
setre, and prolegs well developed on segments III to V and last.
The young caterpillars are usually miners of leaves, bark, or fruits, and puncture
the plant cells with their flat mandibles to suck up the sap. Later stages
feed normally upon the green tissues within the mines, or they may fold, web,
and skeletonize or devour the leaves. Certain ones mine the stems and fruit,
and the members of the oriental genus Epicephala Meyrick feed on seeds.
Pupation occurs in thin cocoons within the mines or rarely in rolled leaves or
elsewhere outside the mines. The pupre protrude from the cocoons upon emergence
of the adults.
The family is widely distributed throughout the world. The most primitive
genus is Gracilaria Haworth with about 120 described species. One of the best
known species is the European lilac leaf miner, G. syringelia (Fab.), which has
been introduced into parts of North America. The azalea leaf miner, G. azalere
Busck, introduced from Japan into North America, is a pest in greenhouses.
G. coffeifcliella Motschulsky attacks coffee in western Africa, and G. theivora
Walsingham infests tea in Malay. The genus Lithocolletis Hubner is the largest
and most important in the family and includes more than 200 species, many of
which are quite destructive to forest, ornamental, and cultivated shrubs and
trees particularly of the north temperate regions. It is believed to have originated
recently in North America. Needham, Frost, and Tothill (1928) list
94 leaf-mining species in this country, and Forbes (1923) describes 73 from
New York and neighboring states. The larvre mine mostly the foliage of broadleaved
deciduous trees.
Members of the genus Marmara Clemens are important because the minute
fiat larval of certain species, notably M. pomonella Busck of North America,
mine the outer epidermis of fruits while other species mine both fruits and the
stems, shoots, and branches of shrubs and trees. Pupation occurs in a thin
cocoon outside the mine which in the case of M. arbutiella Busck is decorated
by small white translucent globules excreted from the anus.
Family LYONETIIDlE Stainton 1854 (Ly'o-net-i'i-dre, named for the Dutch
entomologist and naturalist, P. Lyonet, who published a remarkable work
on the anatomy of the European goat moth in 1760). Ribbed-case Bearers.
A small family of widely distributed minute moths scarcely larger than
those in the family NEPTICULIDiE. The adults are often brilliantly colored.