REPORT OF THE STATE ENTOMOLOGIST 1918 199 
This insect is possibly Cecidomyia erubescens O.S° 
though as no stage of the insect was described, it is impossible to 
be certain without exhaustive rearings from a variety of marginal 
oak leaf rolls. The species was discovered by W. V. Tower in July 
1905, working on the leaves of black oak. His observations on its 
life history were continued by H. M. Russell and subsequently 
C. W. Hooker completed the account. The marginal rolls (pl. 13, 
fig. 1) produced by this insect were very abundant on a black oak 
(Quercus coccinae, var. tinctoria) growing near the 
president’s house on the grounds of the Massachusetts Agricultural 
College at Amherst, Mass. The infested tree was in a small clump 
of red oaks, none of which became infested, apparently indicating 
that this species occurs only on the black oak, particularly as the 
larvae were numerous upon the leaves and adults occurred in swarms 
under its branches. Every leaf was infested by from one to over 
one hundred larvae up to certainly within to feet of the top, though 
they were not so numerous on the upper branches as on the lower 
limbs. Our own observations show that certain Cecidomyiidae at 
least, display a marked preference for the foliage of the lower limbs. 
Male. Length 1mm. Antennae one-fourth longer than the body; 
thickly haired, dark brown; fourteen segments, the fifth with stems 
three-fourths and two times their diameters, respectively; terminal 
segment, distal enlargement slightly produced, apically an irregular 
conical projection. Palpi; the first segment rather long, stout, 
expanded distally, the second a little longer, more slender, the third 
one-half longer than the second, more slender, the fourth three- 
fourths longer than the third, somewhat dilated. Mesonotum dull 
black. Scutellum deep red, postscutellum yellowish. Abdomen 
deep red, the basal segments fuscous. Wings hyaline, costa reddish 
brown; halteres pale yellowish. Coxae, femora and tibiae mostly 
fuscous yellowish, the tarsi a little darker; claws long, slender, slightly 
curved, the pulvilli a little shorter than the claws. Genitalia; 
dorsal plate short, broad, deeply and triangularly incised, the lobes 
diverging, narrowly and irregularly rounded; ventral plate long, 
broad, the sides somewhat emarginate, broadly and roundly emar- 
ginate, the lobes short, obtuse; style stout, long and tapering, nar- 
rowly rounded. 
Female. Length 1.; mm. Antennae one-half the length of the 
body, sparsely haired, reddish brown; fourteen subsessile segments, 
the fifth with a length two and one-half times its diameter; terminal 
segment slightly produced, with a length four times its diameter 
and a short, stout process apically. Tarsi; first segment subquadrate, 
the second with a length twice its diameter, expanded distally, the 
third a little longer, narrowly oval, the fourth one-half longer than 
the third, slightly dilated. Ovipositor one-third the length of the 
abdomen, the terminal lobes with a length twice the width, narrowly 
oval. Otherwise nearly as in the male. Cecid. 1339. 
