172 INSECTS INJURIOUS TO FOREST AND SHADE TREES. 
when carefully inspected, will be found scarcely less curious. How won-— 
derful is nature, that thus presents an interesting subject for our study 
in each particular track an inch or two in length which a family of little 
worms make as they eat their way along in the bark of a tree, the 
parenchyma of a leaf, or elsewhere! How marvelous, that in such 
minute and seemingly unimportant and insignificant operations, we in- 
variably meet with so much to admire! (Fitch.) 
35. THE LEAST WHITE-PINE BARK-BORER. 
Pityophthorus puberulus Leconte. 
Very abundant under the bark of the white pine, a very small timber-beetle with 
long narrow secondary galleries branching off from the main one. 
This may possibly be the insect which Dr. Fitch has regarded as the 
Tomicus pusillus of Harris. We have found the mines in abundance 
under the bark of the white 
pine at Providence, R. I., some- 
times four or five occurring in 
the space of six or seven square 
inches. They vary a good deal 
in irregularity, and we will 
select the one here figured for 
description as being one of the 
more regular mines. The main 
. gallery is slightly sinuous, from 
14 to 2 inches long, originally 
notched alternately on the sides, 
the notches where the eggs are 
laid being the starting point 
for the secondary galleries 
where the larve have. hatched 
and lived. About fifteen sec- 
ondary galleries arise from each 
Fic. 77.—Mine of least white-pine bark-borer, Providence, side of the Pe ee = 
R. I.—Packard del. longest being about two-thirds 
as long as the primary gallery; all end in a slight enlargement in which 
the larva transforms, or connect with the hole through the bark for the 
exit of theinsect. (The figure, as engraved, makes the main gallery and 
branches somewhat wider than in nature, and wider than in my original 
drawing.) The width of the main gallery is 1$™™; of the secondary 
gallery, 1™™, In some cases two main galleries cross each other, while 
in another case two unite to make a figure 8, but in such a case the 
secondary galleries do not cross the main ones, and in examples where 
two main galleries run parallel and somewhat near each other, they 
do not send secondary galleries into the narrow interspaces between the 
two main galleries. 
On submitting specimens of the beetle to Dr. Leconte for identifica- 
