382 
JOURNAL OF ECONOMIC ENTOMOLOGY 
[Vol. 13 
ceps are dark brown or black. Hatching from the egg during June 
and July, the girdler starts mining through the bottom of the shell and 
under the bark. By the middle of the first winter it has grown to be 
7 mm. long and has extended its mine down the small twigs for from 
one to three inches. Most of the twigs have been spiralled and the 
foliage has faded to yellow. At this time some of the girdlers are under 
the bark and some have gone into the wood. Mining is continued 
during the succeeding spring and summer until the second winter, when 
the girdler has mined down the branch for about 6 to 12 inches and has 
grown to about 15 mm. long. Most of the foliage is reddish brown or 
rusty looking. The girdler now goes into the wood and lies out¬ 
stretched in the center of the branch for most of the winter. In the 
spring it continues down the branch under the bark for an inch or 
more and then turns and retreats back up for several inches before it 
again enters the wood and forms the pupal cell. In the Santa Clara 
Valley this takes place about the middle of May. The girdler is now 
full grown and it soon shortens up to about half its former length and 
gets ready to pupate. The pupal cell is usually formed at an angle to 
the surface of the branch, the mine entering the wood and angling up 
to the surface for the emergence of the beetle. 
The Pupa. The pupa when first formed is a delicate whitish 
object with the head, body, wings and legs faintly indicated. It is 
about 7 to 9 mm. long and 1 to 2 mm. broad. The eyes soon commence 
to darken and in about two weeks all of the head, thorax and under¬ 
side of the body have changed to a brownish bronze. The wings and 
elytra, which are folded on the breast and the dorsal surface of the 
abdomen, remain white. Upon the transformation of the pupa to the 
beetle which now takes place the wings and elytra change to the back 
and the elytra soon take on the normal bronze color of maturity. 
This is done without going through the interesting color changes of 
some of the other species like politus. Most of the pupae were found 
in the field during the last of May and the first of June. Some have 
been found in April. 
The Beetle. The beetle is a slender brownish bronze insect 
with a coppery or slightly golden thorax. Its length is from 5 to 7 
mm. and its breadth from 1| to 2 mm. The males have dark green 
faces and the females brownish bronze ones. The claws are cleft in 
such a manner that the lower portion is turned inward and the hind 
tarsi; are stout and obviously shorter than the tibiae. The newly formed 
beetle stays in the pupal cell for several days before it eats its way to 
the outer world. After this emergence, which takes place during May 
and June, the beetles fly around in the warm sun, feed on the edges of 
the leaves of the oaks and mate. Soon after mating the female lays 
