SCOLYTUS DEODARA, MS. 221 


The branches are always of a fair thickness, being as much as 
8 inch in diameter at times, there being several forks or side 
branches above the spot attacked. The beetle bores into the 
branch to the cambium layer and then mines in this horizontally 
round the stem until it has completely girdled the branch, the 
gallery being kept so horizontal that the insect always exactly 
meets, or very nearly so, its hole of entrance. The groove goes 
deeply into the sapwood as well. (See Pl. XII, fig. 2, A, 1.) 
At the upper edge of the gallery small nicks are cut on the 
shady side of the branch and eggs laid. More than one egg is 
laid and the number may be as many as eight, perhaps more. 
Pl. X, fig. 53, b, shows a branch girdled by this insect at (Dye 
After laying her eggs, the beetle leaves the branch by the 
hole of entrance which is just above the groove and may 
possibly attack others in the same way before she dies. 
This point has not been fully observed as yet. Owing to the 
deep groove cut by the beetle and the heavy weight of the needle- 
bearing branch above it, the latter very soon bends over and hangs 
down (until it does this, there is nothing to show that the branch 
has been attacked save the small entrance hole from which resin 
exudes), attached by a few shreds of bark and wood to the branch 
below the cut and a certain amount of resin exudes round the 
groove. This pendant position of the fresh green branches 
renders fresh attacks at once perceivable, and the amount of 
damage done by these beetles, once their life history is under- 
stood, is.very easily discoverable. Pl. XII, fig. 1 shows a dead 
top, girdled the previous year, hanging down in this manner. 
The young larve hatch out, from the eggs laid in the nicks 
above the girdle, in a few days since quite young larve are to 
be found just boring away from the cut whilst the cut branch is 
still quite fresh and green. The girdle is of course made by 
the beetle to prepare a sufficiency of food material in the 
withering condition required by the larva developing from 
the eggs. The larve bore straight up the girdled branch 
in the cambium and sapwood eating out slightly winding 
galleries about 13 to 2 inches in length which are filled 
all the way up with wood dust and excrement (see Pl. X, 
fig. 5, b (2)). When full grown, they eat out in the sapwood a 
