61 



before they are iu full leaf can be easily removed, and in this way the 

 liner trees can be protected. The eggs are also removed in the late 

 antunm and winter, as they are very conspicuous. 



Tanessa and Graptasi^. are sometinies very abundant, and are collected 

 and destroyed as soon as discovered. Gecropia and Eacles are always 

 al)undant and on many of the smaller trees do much damage. These 

 are hand-picked and destroyed. 



Alypia octomaculata is one of our most troublesome caterpillars, the 

 great abundance of Ampclopsis vines in the parks, and especially around 

 it, covering "squatter sovereignty" houses, affords congenial food for its 

 rapid propagation. In the parks the vines are twice annually treated 

 with a fiolution of London purple, applied with a spraying machine. 

 This is found most effective and the vines do not seem to be injured as 

 easily as most plants by the arsenites. 



The Elm Beetle, Galeruca xanthomelama, has given us an immense 

 amount of trouble, and many thousand trees have been sprayed each 

 year for their destruction, and witli good effect. The means we have 

 adopted during the past three years is rather more in the preventive 

 line. As soon as the first eggs are found that part of the tree is at 

 once sprayed. I am inclined to think the Elm Beetle is double-brooded, 

 with us. 



The Elm Borer, Zeiaera pyrina, is getting to be very destructive with 

 us, already twelve species of trees and shrubs are affected by it, and 

 during the i)ast year two men were kept during May at collecting the 

 larvjB from broken branches. All branches as soon as detected in a 

 weak or broken state are removed and the larv.e extracted. In very 

 choice trees the limbs are carefully examined and where holes can be 

 found bisulphuret of carbon is put in with an oil can and putty put over 

 the hole. This is onlj^ resorted to in the case of rare trees and shrubs. 



For scale insects the trees are washed with preparations and then 

 cleaned with steel brushes, leaving all in fine condition. Many thou- 

 sand trees- and shrubs have in this way been put in fair condition. 



A large number of poisons have been exi)erimented with for Aphis 

 and other insects, due notice of which will be given in reports soon to 

 be published. 



The spraying machine used by the department of public parks is a 

 two-barrel machine manufactured by the Nixon Nozzle Company, Nixon, 

 Illinois. This machine, to better adapt it for city work, has been en- 

 tirely remodeled. A set of strong cab wheels, with a strong axle, was 

 first made, then a pair of strong eas}'^ springs, so as to make the tank 

 less liable to jars. The tank was lined with zinc entire, and on top of 

 the tank was placed a well about a foot high to keep the liquid from 

 flushing over. On the rear of the tank was placed a box for poisons, 

 hose, etc., and on the front a box for coats, lunches, and collecting cases 

 and bottles. On one side of the machine and running nearly to the 

 horse's breast was placed the bamboo pole used to elevate the hose, 



