ANNETTE F. BRAUN 
163 
of the larva from the mine. The larva leaves the mine by a semi- 
circular slit in the upper or the lower epidermis and spins the 
characteristic cocoon, usually brownish, but occasionally yellow- 
ish or whitish, in the surface soil or amongst rubbish, often near 
the base of the tree; occasionally it spins on the twigs or branches. 
Pupation does not take place immediately; in the summer gener- 
ations it occurs a few days before emergence, in the overwintering 
generation it may be delayed until spring. 
A few species have but one generation a year; most species (in 
the latitude of Cincinnati) have two or three; a few of the oak- 
feeding species may have as many as four generations. The 
length of the life cycle is approximately six weeks, except in the 
case of the single-generation sjiecies, where several months may 
elapse between oviposition and the attainment of full growth by 
the larva. The moths from the over-wintering generation of 
larvae emerge in i\Iay and June, a few species in April. 
A comparison of blotch-making species with linear-mine species 
would seem to indicate that in some respects the former are more 
primitive, since these species are practically identical with the 
earlier Ectoedemia in wing structure. This is not universally 
true, however, and the fact that some of the smaller linear mine- 
making species (in which veins K 4 and R 5 are coincident and M 
coalescent with R) are very closely related in general habitus to 
these blotch-makers, may indicate that the differences in venation 
are directly due to size and breadth of wing. 
Where species described in the genus Nepticula have not been 
available to the author for examination, they have been tenta- 
tively retained in this genus. Localities cited under geograph- 
ical distribution without authority stated are from the author’s 
personal observations. 
Only the references to original descriptions and notes published 
subsequent to Dyar’s List (1902) are cited under each species; 
for other references the reader is referred to Dyar’s List. The 
scientific names of plants of the eastern United States are those 
used in Graj^’s New Manual of Botany (Seventh Edition). 
‘The name StigmeUa Schranck (Fauna Boioa, ii, (2), j). 169, (1802) is a 
nomen mulum, no species having been mentioned. 
TRANS. AM. ENT. SOC., XLIII. 
