536 REPORT OF THE COMMISSIONER OF AGRICULTURE. 



with care, they slioukl be cut off or burnod off; and if cut off, they 

 shoukl be burned at once. The ''tree-pruners," manufactured for 

 the trade v.nd well known to all gardeners, answer the purpose ad- 

 mirably. 



The customary method of burning the nests is by means of rags 

 saturated with kerosene or coal tar and fastened to the tip of a long 

 pole. An old s]ponge has been substituted to advantage for the rags, 

 but probably the best substitute for this purpose is a piece of porous 

 brick. In a pointed communication published in the Ei'eninn Star 

 of August 21, Major Key, agent of the Humane Society, thus de- 

 scribes the making of a "brick-torch: " "Take a piece of soft brick, 

 commonly termed salmon brick, trim it to an egg shape; then take 

 two soft wires, cross them over this brick, wrapping them together 

 around the opposite side so as to firmly secure it; now tie this end to 

 a long stick, such as the boys got at the planing-miils, by wrapping 

 around it; then soak the brick in coal-oil, light it with a match, and 

 you are armed with the best and cheapest weapon known to science. 

 Holding this brick torch under the nests of caterpillars will precij^i- 

 tate to the sidewaljv all the worms on one or two trees at least from 

 one soaking of the brick, and it can be repeated as often as necessary. 

 Then use a broom to roll them under it, and the work will be done, 

 the controversy ended, and the trees saved." 



A little thorough work with a simple torch like this, at the right 

 time, will in nearly every case obviate the necessity of the more ex- 

 pensive remedies later in the season, when the worms of the first 

 Drood have grown larger, or when the second brood has api3eared. 



Mulching. — After a bad caterpillar year a little judicious raking 

 together of leaves and rubbish around the trunks of trees which have 

 been infested, at the time when the worms of the second brood are 

 about full-grown and before they commence to wander, will result in 

 the confinement of a large proportion of the pujiSB to these limited 

 spaces, where, with a little hot water or a match, tliey can readily be 

 destroyed during the winter. Many of the caterpillars of course 

 reach the ground by dropjung purposely or falling accidentally from 

 the branches, but the great majoritj^ descend by the trunk, and find- 

 ing the convenient shelter for pupation ready at the foot of the tree, 

 go no farther. This has been tested on the Department grounds the 

 past season, and is mentioned as a method of riddance supplementary 

 only to others. 



Arsenical Poisons. — It is seldom, however, that individuals, and 

 still more rarely that corporations, can be brought to the use of reme- 

 dies until damage is plain, and when this time comes nothing is bet- 

 ter than the apx^lication of some one of the arsenical mixtures. We 

 have already treated of the methods for applying such mixtures to 

 shade trees on a large scale in our report as Entomologist to the De- 

 partment for 1883, and in Bulletin 6 of this division, in both cases 

 in connection with the treatment of the Imported Elm Leaf -beetle 

 {Oaleruca xantJiomelcena). 



The most economical and convenient apparatus consists of a large 

 barrel, provided with a force-pump and mixer, mounted on an ordi- 

 nary cart. A long hose, a metallic pipe, and a cyclone nozzle, ar- 

 ranged for elevation by means of a bamboo pole, complete tlie outfit. 



Detailed descriptions of the apparatus having already appeared in 

 the reports just mentioned, it is unnecessary to repeat tliem here. 



A somewhat similar a]:)paratus is used in the California orange 

 groves against the Cottony Cushion-scale, and is illustrated in opera- 



