August, '21] burke: carpenter worm control 371 



ter elms. Slightly or moderately infested elms are to be treated by 

 cutting out and probing for the smaller larvae, probing for larger ones 

 and injecting carbon bisulphide in the mines of those that can not be 

 reached by the fonner methods. Doane (Joiir. Econ. Ent., Vol. 5, 

 p. 348) recommends the carbon bisulphide injectment treatment. 

 Childs (Month. Bui. Calif. State Com. Hort. Vol. Ill, p. 264) also re- 

 commends the bisulphide treatment and the removal of tniimportant 

 trees which harbor the pest. 



The above m.entioned methods are undoubtedly good and when 

 carefully and patiently applied will bring success. It is doubtful, how- 

 ever, if the average gardener or arboriculturist can follow up a heavy 

 infestation thoroughly enough to stop it. From a single elm stump 

 about twelve inches high and eighteen inches in diameter left in con- 

 trol work the writer took twenty-six larvae which varied from one inch 

 to two and a quarter inches in length and which appeared to belong 

 to at least four generations. Following up each mine of such a heavy 

 infestation in a large tree and either catching the worm or killing it by 

 fximigation is very tedious and takes considerable tim.e and skill which 

 makes it expensive. 



There is one splendid live oak in Los Gatos which is worth easily 

 $1500.00 to the property on which it stands. It is four feet in diam- 

 eter, had a main trunk height of about twelve feet, a total height of 

 fifty-five feet and a spread of sixty feet. The foliage is in almost per- 

 fect condition but the main trunk and the bases of the larger branches 

 are much scarred by the work of the carpenter worm. During the 

 past ten 3'ears the owner has spent about five hundred dollars for pro- 

 tection, yet the tree is still infested with several generations of worms. 



The work of the insect was noticed first in this tree about ten years 

 ago. The trunk was heavily infested so a tree siirgeon was employed. 

 He went carefully over it, cut off most of the bark and so far as can be 

 determined did a very thorough job. For about four or five years 

 aftenv'ards the tree appeared to be in very good condition and no in- 

 sect work was noticed. The trunk then became infested again and 

 the regular gardener was put to work on it. He consulted all of the 

 authorities he could find and was given the standard recommendations. 

 These he very' faithfully tried to carry out but the tree still showed 

 signs of infestation so last spring he went over the trunk again, cutting 

 out worms and injecting carbon bisulphide and to complete the job 

 gave it a heay>^ coat of white wash and sprayed it during the first of 

 July with strong kerosene emulsion. The white- wash made the over- 



