2 BULLETIN 1079, U. S. DEPARTMENT OF AGRICULTURE. 
Frequently, however, storms blow over many millions of feet of 
saw timber. Cases are on record where a single firm has lost in such 
a manner 100,000,000 board feet. It isa physical impossibility to log 
these trees promptly and get them to the saw or into a place of safety, 
although from 40 to 60 days’ delay may mean total destruction of the 
sapwood by borers. Jt might be feasible, however, to saw these trees 
into log lengths and spray with some solution that would prevent 
insect attack for two or three months, or until it was possible to haul 
them to the mill. 
The increasing use of the national forests and parks for recrea- 
tional purposes has resulted in the construction of many rustic cabins. 
Insects attacking the timbers in these buildings cause annoying exu- 
dations of boring dust and loosen the bark so that later it peels off, 
thus marring the artistic effect. Much of this injury to rustic work 
could be prevented by cutting the trees at certain periods and by 
proper seasoning. Frequenters of summer camping grounds can not 
always plan to cut the trees at the proper time; in fact, it is more 
frequently the case that the building is constructed during the sum- 
mer months and the timber felled at that time—a period when the 
wood is most susceptible to insect attack. 
Thus in both situations it is often the case that the more practical 
and economical means can not be used. 7 ; 
There is also a considerable demand for a suitable repellent spray 
against certain shade-tree insects. Wood borers attack various spe- 
cies of living trees, causing considerable injury or death. Under 
certain circumstances a spray could be used advantageously to repel 
such insects and prevent oviposition. It would necessarily have to 
be of materials that would not burn the younger bark, although, 
except for mechanical difficulties, it would only be necessary to apply 
the spray to the main frunk and larger limbs, since these are the only 
parts attacked. Spray materials, the cost of which would be pro- 
hibitive for the protection of forest products, might be employed on 
shade trees. 
Under circumstances such as the foregoing it is evident that a 
practical spray for the prevention of insect injury would be of much 
benefit and its use should result in a considerable saving of forest 
products and shade trees. 
Owing to the many different insects, their different methods of 
attacking the logs, the many kinds of wood to be protected, and the 
exposure to weather conditions, the practical solution of this prob- 
lem presents many difficulties. Several solutions have been found 
to meet the requirements, except that they are too expensive or too 
difficult to apply. In the hope that the results so far obtained may 
be a stimulus for further suggestions or work along this line the 
