INSECTS INJURIOUS TO THE PINE. 193 
64. THE PINE-TWIG TORTRIX. 
Retinia frustrana Scudder. 
Order LEPIDOPTERA; family TORTRICID®. 
Infesting the new growth of Pinus inops and pitch-pine (P. rigida) (and perhaps of 
other species), spinning a delicate web around the terminal bud, and mining both the 
twig and the bases of the leaveg; one or several small yellowish larvee which trans- 
form within grayish cocoons, either in their burrows or fastened to the twigs, and 
become small copper-colored moths, with wing expanse of 12™™ (0.47 inch). 
“About the middle of May, 1879, the scrub-pines (Pinus inops) in Vir- 
ginia, near Washington, were found to be greatly injured by small 
lepidopterous larvee. On many trees there 
was scarcely a new shoot to be found which 
was not infested at its tip by from one to four 
yellowish black-headed caterpillars. They 
were so completely concealed while at work 
that their presence would scarcely be noticed, 
and the effect of their work was hardly visible 
until the twig was almost completely destroyed. 
Upon close examination a delicate web was 
seen inclosing the base of the bud, and the sur- 
rounding new leaflets, resembling much the \§%f 
nest of a small spider. When this web was re- 
moved, one or several little yellow caterpillars 
were seen retreating into a mine in the bud or 
into the bases of the leaves, which were also Fic. 82.—Retinia frustrana Seud- 
. F der, larva, pupa, adult and work. 
mined, or, not infrequently, they dropped from ——From Comstock. 
the twig, suspending themselves by a silken thread. The bud was often 
so hollowed that it dropped to pieces almost at a touch. 
‘“‘At the time when they were first noticed larve of almost all sizes 
were to be found. Some were apparently almost full-grown, while 
others had evidently not been long hatched. The nearly full-grown 
Specimens measured 8™™ (0.31 inch) in length. The first pup were 
obtained early in June. Most of the larvee transformed within the bur- 
rows which they had made, first spinning more or less of a silken en- 
velope about themselves. Others, however, issued from their mines, 
and spun rather tough grayish cocoons between the leaves. The pup 
were short, stout, and brown in color, with each segment furnished dor- 
sally with two serrated lines, one consisting of large and the other of 
fine teeth. 
“The first moths issued June 13, the pup having previously worked 
their way, by means of the spines just mentioned, into such positions 
that they could give forth the moths without injury to the latter, and a 
few weeks later almost every shoot had one or more of the empty pupa 
skins protruding from it. Specimens of the moths were sent to Pro- 
fessor Fernald, who determined them as identical with Mr. Seudder’s 
manuscript species Retinia frustrana. In August Mr. Scudder gave a 
short account of this insect before the entomological section of the 
13 RIL 
