lis ANNUAL REPORT OF THE Off. Doc. 



spicuoiis on accouiil of (he white covering of fine, waxy threads, 

 which are secreted on their bodies, and a group of them resembles 

 a tuft of cotton or wool. While they make knots on branches, the 

 liTont injury is done l)y llieir work on the roots, the bark of which 

 tlicy puncture wi(h (heir l)eak}>! in thoir eft'orts to suck cut the sap. 

 This causes swellings or enlargements on the roots, not unlike crown 

 gall. Moreover, the ants, always present with the aphids, upon the 

 secretions of which insects they feed, tunnel about the rootlets of 

 the trees, and separate them from the earth. 



Treatment: The insects above ground can be destroyed by spray- 

 ing or painting by hand with an eight or ten per cent, kerosene 

 emulsion, or whale oil soap, one pound to five gallons of water, or 

 with boiled lime-sulfur solution; or infested aroas can be painted 

 over with ordinary house paint. The insects underground should 

 be treated with one of the following: Kemove some of the groun<J 

 near the trunk of the tree, and apply fine tobacco dust on the ground 

 above the roots, or pour tobacco decoction, made by steeping one 

 pound of tobacco leaves in one gallon of water on the roots of the 

 tree, or apply eight or ten per cent, kerosene emulsion to the roots 

 of the tree, or fumigate with carbon bisulfide by making a hole with 

 a stick, down to the roots at several points about the tree and pour 

 into it one-fourth pint of carbon bisulphide. 



Spring spraying with the lime-sulfur solution will destroy the eggs 

 laid upon the bark of the tree. 



H. A. SURFACE, 

 Economic Zoologist. 



DEPARTMENT OF AGRICULTURE— DIVISION OF ZOOLOGY 



BORERS 



The larvae of certain insects are called borers, because of their 

 habits of boring or tunneling beneath the bark, and even into the 

 wood of trees upon which they feed. They destroy the living bark 

 and sap wood, thus cutting off the connection between the roots and 

 the leaves of the trees, injuring or killing them. 



The most important of these borers are the following: 



The Round-headed Apple-tree Borer. This is one of the worst 

 enemies of the apples trees. The larvae is cylindrical in shape, and 

 first bores into the soft sap wood by making a circular tunnel, when 

 it works into the harder wood, and after nearly three years it 

 emerges, usually several inches above the point of entrance. 



Treatment: Before the borer has entered the hard wood, it can 

 easily be cut out by using a pointed tool, such as a pruning knife, 

 but after it has worked its way into the wood, the best method of 

 treatment is to inject a few drops of carbon bisulfide into the tunnel, 

 using a spring-bottom, oil can for the })urpose, and closing the open- 

 ing of the tunnel with soft clay. 



The Flat-headed Apple Borer attacks a variety of trees. This borer 

 makes irregular tunnels in and just beneath the bark, working into 

 the wood only for a short distance before pupation. 



