fj 
ing.? Metal syringes may also be used, but it is more difficult to 
measure the exact amount and the bisulphid acts on the leather 
packing. Rubber syringes can not be used because of rapid corrosion. 
About a teaspoonful of the liquid bisulphid is sufficient for each 
burrow. 
For stopping the holes after injecting the liquid, putty and moist 
clay, advised by some, have not been found so serviceable as grafting 
wax. Coal tar may be substituted for the latter, or the holes may be 
closed by inserting a wooden plug and breaking or sawing it off level 
with the trunk. In any case the stopper should be tight, to exclude 
water from rains, which might tend to produce decomposition of the 
surrounding wood or invite other insects, like black ants and second- 
ary borers, of which there are many species, and injurious fungi. 
Carbon bisulphid should be handied with the usual precautions 
against fire, which means that the operator should not smoke while 
at work. Although a deadly poison, it will not injure ordinary 
trees when applied as described. 
Killing with wires.—It is possible to reach and destroy some larve 
by torcing a copper or other pliable wire into the channels. This is a 
well-known borer remedy. It is impossible, however, by this means 
to kill the insects in all cases, owing to the length or crookedness of 
the burrows. Bisulphid of carbon should then be used. 
Electric ghts.—To what extent electric lights are serviceable as an 
agency in the destruction of the moths of this borer has not been 
definitely determined. Col. Nicholas Pike and Dr. J. B. Smith, 
however, have advised placing shallow pans around electric-light 
poles in and around parks to attract the moths. The pans are par- 
tially filled with water and a few drops of kerosene are poured into 
them. The moths flying against the globes drop into the pans and 
are promptly killed when they come into contact with the oil. In 
this way many males can be destroyed. 
Inspection.—In large parks the destruction wrought by this borer 
annually is an important item, and it will be found a source of profit 
to establish a system of inspection consisting in the employment of 
parkkeepers and boys, and others who may be engaged at lower 
a During the last years of the nineteenth century a long row of beautiful red oaks 
bordering the street between the grounds of the Department of Agriculture and those 
of the Smithsonian Institution were badly infested by the related carpenter worm 
(Prionoxystus robinie Forst.). Nearly every tree was infested and frequently two or 
three burrows showed near the tops of the trunks. Bisulphid of carbon was applied, 
as described above, and the holes closed with grafting wax. A year later no insects 
could be found at work, but wherever this remedy had been applied a small scar 
remained. Two years later these had entirely disappeared and the trees looked as 2 
they had never been infested. 
(Cir. 109] 
