389 
been its original food plants. This very general failure of development 
from the egg, if normal, will detract somewhat from the injurious char- 
acter of the insect. The severing oi" the terminal twigs is, however, 
the principal damage after all, since the work of the larva, as will be 
indicated below, only causes the death of three or four inches more of 
the twig. 
In the twig in which successful development had . taken place, the 
larva had worked down from the tip some 3J inches, eating out the 
entire pith and inner layer of wood, leaving only a very thin shell. The 
interior of the twig was densely packed with the larval excrements 
down to within three-fourths of an inch of the base of the burrow, where 
the larva had hibernated in a delicate cocoon. The cocoon is a little 
over one-half an inch long, and consists of a very slight silken lining 
Fig. 43.—Phylteecv.s flaviventris i a, larva; b, antenme and mouth-parts of same; c. dorsal view of tip 
of abdomen; d. lateral view of same; e, pupa; /, larva in twig in hibernating cocoon, a, e, enlarged; 
b, c, d, greatly enlarged; /, natural size (original). 
of a portion of the burrow. A section of the burrow, showing the 
cocoon and contained larva, is given in the accompanying illustration 
(Fig. 43/). 
The larva passes the winter practically unchanged in this cell, and 
at the time of examination had not transformed, although pupation 
was near at hand, as indicated by the fact that the compound eyes 
were already showing through the head. The larva is a little over half 
an inch long, and is creamy white in color, with the mandibles and 
labium brown, darkest at tips, and the area back of the base of the 
mandibles, together with the tips of the antenna 1 , maxilla', and horny 
tip of abdomen somewhat lighter brown. The peculiarities of struc- 
ture of the larval mouth-parts, and the peculiarly spiny projection 
terminating the body, are indicated in the accompanying illustration 
(Fig43fc, c, d). 
L8391— No. 5 3 
