POLYGRAPHUS MAFOR, MS. 238 
aes st — al lk SK 2a 
Life History. 
The beetles are to be found towards the end of April bor- 
ing into the trees for the purpose of egg-laying, both blue pine 
and spruce being affected. The first brood of beetles from 
these eggs appears during the latter part of June (probably 
earlier in favourable situations), the generation taking from six 
to seven weeks to pass through. The beetles maturing in June 
at once commence egg-laying and a second brood of adults 
makes its appearance during September, whilst a third genera- 
tion or a portion of it is passed through before the winter coli 
puts an end for the time being to the insect’s activity, In 
favourable situations and years it is not improbable that this 
number of generations is increased, the spring and summer life 
cycles being gone through at a quicker rate. 
The beetle bores its way in from the outside, and on reach- 
ing the bast gnaws out in it and the sapwood a chamber of 
irregular stellate shape (see Pl. XIII, fig. 2, b, c (p)). From this 
chamber usually three, occasiona!ly four or five, arms or branches 
take off (fig. 2, b,c, (e)). These branches are the egg galleries 
and they are bored deep in bast and sapwood, being usually 
curved and about an inch in length on large branches, The 
female beetle, as she bores out her tunnel, gnaws out little 
indentations at the side, placing an egg in each, These appear 
to be made more on one side than the other as she bores away 
from the pairing chamber (see PI. XIII, fig. 2, b (e)), the notches 
being closer together on this side whilst only a few scattered 
ones are on the other. From 8 to 15 eggs appear to be 
laid in each gallery. The larve, on hatching out, feed in 
the bast at first, but as they get older they go into the 
Sapwood and feed there. They bore winding galleries in 
a direction approximately at right angles to the egg gallery, 
their tunnels averaging 4 to $~ inch in length. When full 
grown they eat out a small chamber in the wood at the end 
of the larval gallery before changing to the pupal stage. The 
pupal stage is passed in this, and the beetle when mature bores 
its way out by a horizontal gallery direct to the outside, 
Occasionally the larva feeds almost entirely in the bark, but it 
