226 | TOMICUS SP. 


Life History. 
The Blue Pine Tomicus beetles appear on the wing towards 
the end of April at elevations of about 7,000 feet, the date of 
first appearance varying with the elevation at which the insect 
is living, being later at higher elevations, These beetles lay 
eggs from which the beetles of the first generation of the 
year mature about the middle of June. At the lower elevations 
it is probable that a second lot adults make their appear- 
ance about the end ef August, I have obtained a third brood 
about the middle of September, whilst in favourable seasons 
and localities a fourth, or portion of a fourth, generation is 
completed before the winter sets in and puts an end to its 
activity, 
The beetles are found in April boring into the trunks of blue 
pine (Pinus excelsa) of all ages from the pole stage upwards. 
When it has reached the bast, the insect gnaws out an irre- 
gularly shaped pairing chamber, oftenas much as $ x 3 inch in 
size. (See Pl. XIV, Pl. XV, fig. 1.) When this is ready, 
coupling takes place, several female beetles entering by the 
same turnel and being fertilized by the male, Usually from 
2-5 egg-galleries are excavated, grooving both bark and sap- 
wood, radiating from the pairing chamber (PI. XIV, e, PI. XV, fig. 
1,e) and more or less in the long axis of the tree. These 
galleries, which contain generally only one air-hole (Pl. XIV, a) 
t.é., a hole bored horizontally through the bark to the outside to 
admit air into the egg-gallery, are from 24 to 3 inches in 
length and are bored by the female beetles, On the right and 
left, but apparently chiefly on the right, the 2 eats out little 
recesses, laying in each an egg, from 20 to 30 being generally 
deposited in each gallery; the galleries are blocked up with 
wood-dust. As it is probable that only one egg-gallery is bored 
by each ¢, it would appear that the ¢ beetle pairs with 2-5 
females, Pl. XIII, fig. 1, d shows the pairing chamber, ps 
and three partially completed egg-galleries, e, with a beetle in 
the shorter one. In the two longer galleries the notches in 
which eggs have been placed may be seen on the left edge, 
The first larve make their appearance before the egg-laying 
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