! * 
A FURTHER NOTE ON SCOLYTUS MAFOR, MS. 205 

in the fall and is taken separately), and a length of go feet. 
On every portion of 1’ x 1’ there were on an average 23 
beetle galleries, 2.2, ezg galleries. Now I have shown ‘that 
between 60 and 70 eggs of the larger Scolytus and between 
40 and 50 of the smaller one hatch out into larve which tunnel 
into the wood, and that the larger beetle is more numerous 
than the smaller, in this case in the proportion of 15 to 8 on the 
areas taken. | 
Therefore on every 1’ x 1’ of surface of bole we have— 
Egg galleries of larger Scolytus 
x hatched out larve 15 X 60 = goo 
Do. smaller do. = 8 x 40 = 320 
{} 
giving a total of 1,220 hatched out eggs per 1’ ¥1’, or multiplied 
by 44°5, the number of 1’ x1’ surface pieces in the bole, a total 
of 54,000 larve. 
The 9” x 2” x 16’ of top gave another 2,300 larvee. 
The larger branches were much broken in the fall of the. 
tree in most cases, and their contents, for they were covered : 
with the Sco/yéus egg and larval galleries, may be taken as a! 
set-off to attacks of predaceous insects on the above and over 
estimate of larve hatching out from the eggs. Weare left with 
a total of 56,300 beetles, the product of the first generation of 
the year raised in a single tree, capable of producing 40 to 60 ° 
larvee a piece for the second generation of the year. If we only 
take 50 per cent. of these as arriving at maturity and safely pass- 
ing through the winter, the increase of beetles from one single 
tree is still enormous, the calculation coming roughly to™ 
1,550,000 beetles, It should be noted here that if the trees are — 
felled in spots reached by the midday sun, it will be found ’ 
that the beetles will attack the portion ofthe bole nearest 
the ground and its sides only, leaving untouched the upper ' 
surface, the bark of which, exposed to the full sun’s rays, will 
dry very rapidly and will in consequence be unsuitable for their — 
purpose. In such cases the tree will not raise so many beetles‘ 
as in the case above quoted. We have now to consider another 
important point. If fellings are still being carried out towards 
the end of July and in August, the beetles of the first ’’ 
