SHADE TREE PESTS 



49 



Remedies. These gregarious caterpillars are easily destroyed within 

 the web by removing and burning the infested portion of the limb. 

 They can also be controlled by the use of poisons. 



BORERS IN TRUNK AND LIMBS 



There are several very injurious borers infesting the trunks and branches 

 of elm and maple trees, and since they work under the bark or within 

 the wood, it is extremely difficult to control them. 



Indications of attack. The presence of these insidious enemies 

 is usually indicated by one or more dead branches and a more or less 

 sickly appearance 

 of the tree. Bor- 

 ings or "saw dust" 

 may be found 

 around the base 

 of the tree in some 

 instances, and in 

 bad attacks large 

 patches of loose 

 b rk may be 

 found. On re- 

 moving or cutting 

 into the bark, the 

 familiar work of 

 borers is exposed 



(pl- 3> fi g- 3). and 

 the white, usually 

 legless, somewhat 

 flattened grubs 

 may be seen ly- 

 ing in their bur- ^* s ■ *>• Pigeon Tremex ; a, larva showing the Thalessa larva fastened 

 to its side; 6, head of larva; c, pupa of female; d, male pupa; 

 TOWS. e> adult female — all slightly enlarged. 



Elm and maple borers. The parent of the maple tree borer, 

 Plagionotus speciosus Say, is a handsome black beetle with yellow mark- 

 ings and is represented on plate 3, figure 1. The adult of the more 

 common of the elm tree borers, Saperda tridentata Oliv., is a slaty 

 colored beetle with dull reddish markings and is represented on plate 3, 

 figure 2. The thick fleshy grubs of several curculios or weevils are 

 sometimes found in numbers just beneath the bark of elms and occasion- 

 ally cause considerable injury. 



