Apple. 259 



ornamented with yellowish markings, while underneath it is 

 quite black. The worms mature in about six weeks from the 

 time they are hatched. At this time they generally leave the 

 tree and seek some sheltered corner in which they spin their 

 cocoons. In three weeks moths issue, and eggs are again laid. 



Treatment. This insect does considerable damage if it is left 

 unchecked, but it is so easily destroyed that there is no need 

 of having any trouble with it in an orchard. As soon as a 

 nest is seen, the branch may be cut off and burned, or the 

 insects crushed without the removal of the nest. But a much 

 better remedy is to spray the foliage near the web with arsen- 

 ites. The caterpillars always return to the web at night, and 

 they may also be found there in bad weather ; and if the tree 

 has been sprayed they generally return there to die. In spray- 

 ing for the codlin-moth sufficient poison is applied to rid the 

 orchard of this enemy also. 



Woolly Aphis (Schizoneura lanigera, Hausm.). Description. 

 This insect is a small yellow plant louse. It is found upon many 

 kinds of trees, both on the branches and among the roots, and 

 causes injury by sucking the juices. The insect is protected by 

 a woolly or mealy covering, and from this it has received its 

 common name. When the roots of nursery trees are attacked 

 the stock is almost worthless, for the labor and expense of de- 

 stroying the insects is generally greater than the value of the 

 stock. 



Treatment. Affected branches may be cleaned by throwing 

 a strong stream of water upon them, thus dislodging the 

 insects. Kerosene emulsion and tobacco w^ater will also kill 

 them, if the applications are made so thoroughly that the 

 insecticide will penetrate the covering. It will probably be 

 found necessary to repeat them. Roots of trees standing in 

 the ground may be treated with scalding water. If the roots 

 are to be dipped into the water, a temperature higher than 

 150 degrees F. should not be allowed, and 130-135 F. should 

 kill the insects after a moment's immersion. Kerosene emulsion 

 and tobacco water give good results. They may either be 

 sprayed upon the roots, or these may be dipped into the liquid. 

 In either case the roots must be well cleaned before the appli- 

 cation is made, so that the insecticide will reach the insect. It 

 is possible that the hydrocyanic gas treatment would be of 



