40 FARMERS' BULLETIN 843. 



cause any unnecessary injury to the trees, and the places from which 

 the borers have been removed should be painted with white lead or 

 some good tree paint. 



Certain washes have been used with some little success for protec- 

 tion against this insect in apple orchards, but it is believed that this 

 means of fighting the borer on pecan is impracticable. Since the 

 beetles are to be found in pecan orchards from March until November, 

 several applications of the wash would be required and the cost for 

 the treatment would be excessive. 



In pecan orchards the use of trap logs made from newly cut 

 branches of any favorite host plant, in order to attract the adult 

 beetles for egg deposition, may be found practicable, for it is well 

 known that this insect prefers dead or dying wood to living trees. 

 Perhaps oak would be the best and most available wood to be had 

 for these logs, but hickory or pecan would serve the same purpose, 

 as the borer breeds abundantly in all of them. These trap logs, from 

 4 to 6 feet in length and from 3 to 4 inches in diameter, should be 

 placed at intervals of 100 feet or less during the late whiter or very 

 early spring. After these logs have been left in the orchard for one 

 season they should be burned the following winter. The writer 

 has captured hundreds of beetles on pecan and oak logs that were 

 smeared with a viscous substance and placed in pecan orchards. 

 This plan has not been tested on a large scale, but it promises to be of 

 value, especially in badly infested orchards that have been neglected 

 for some time and are adjacent to extensive woodlands. 



Careful cultural methods are urged strongly as a measure of pro- 

 tection. All dead and dying trees and all pruned limbs or branches 

 should be removed promptly and burned, for such wood affords an 

 ideal breeding place for the borer and is therefore a menace to the 

 orchard. The keeping of pecan wood about the orchard for future 

 use as fuel or for other purposes is a bad orchard practice and can 

 not be condemned too strongly. In several instances the writer 

 has found large numbers of flat-headed borers in limbs and branches 

 of pecan stored for firewood. In the transplanting of nursery stock 

 to the orchard, every care should be taken to have the trees set out 

 under the best conditions; and, judging from observations, early 

 planting, say, in December and January, and not later than Febru- 

 ary, is to be recommended, so that the trees will get the benefit of 

 the winter rains. As a measure of protection it is also essential 

 that young trees be kept in a vigorous growing condition by frequent 

 cultivation and the planting of tree rows to some suitable legumin- 

 ous crop. The use of fertilizers also will help the trees to withstand 

 attack by this species as well as by other wood-boring insects. It 

 is important to remember that thrifty trees are less liable to attack 

 than sickly or stunted ones and injury is best avoided by the main- 

 tenance of trees in a vigorous condition of growth. 



