INJURIOUS AND BENEFICIAL INSECTS OF CALIFORNIA. 



313 



Food Plants. — The following plants are attacked: apple, apricot, 

 mountain ash, cherry, chokecherry, elm, hawthorn, Juneberry, nectarine, 

 peach, pear, plum and quince. According to Quaintance, 225 the plum 

 is the preferred host, while the apple, peach and cherry are equally 

 attacked. In California the apri- 

 cot seems to be preferred equally 

 as much as the plum. 



Control.— Keeping the trees as 

 healthy as possible and inspecting 

 nursery stock to prevent introduc- 

 tion are the most important consid- 

 erations with regard to this beetle. 

 If infestation does occur, all trees 

 which are badly attacked should be 

 removed and burned and the others 

 carefully pruned to remove all the 

 infested parts possible. The appli- 

 cation of a coat of carbolated white- 

 wash (1 pint of 25'/,, crude carbolic 

 acid to 10 gallons of whitewash) is 

 recommended. 220 Prof. E. D. San- 

 derson 227 also recommends the use 

 of a thick soap wash containing a 

 pint of crude carbolic acid to every 

 10 gallons, and quotes Prof. Gos- 

 sard as having attained good results 

 by applying early in spring, mid- 

 summer and October a whitewash 

 to which is added a small amount 

 of table salt or Portland cement to 

 make it stick. Prof. Gossard is also 

 given as the authority for having 

 obtained good results in killing the 

 larva" within their burrows by the 

 application of a spray made by dis- 

 solving 3 pounds of naphtha soap in 

 3 gallons of hot water and adding 

 1 gallon of carbolineum. This is thoroughly agitated while still hot 

 and diluted 1 to 4 of water for use. 



Natural Enemies. — Natural enemies are given much credit for keep- 

 ing down the attacks of this beetle in other states. A chalcid, Chiro- 

 pachys colon Linn. 228 is recorded as the most important. 



225 Yearbook U. S. Dept. Agric., p. 347, 1905. 



= 2(i O'Kane, W. C, Inj. Ins., p. 242, 1912. 



-- 7 Sanderson, E. D., Ins. Pests, Farm, Garden, Orchard, p. 546, 1912. 



-"Chittenden, F. H., Cir. 29, Bur. Ent. U. S. Dept. Agric, 1S98. 



Fig. 305. — Small apricot limb with bark 

 removed to show the galleries made by 

 the larvte and adults and holes made by 

 the adults of the shot-hole borer or fruit- 

 tree bark-beetle, Eccoptogaster rugulosus 

 (Ratz. ). Enlarged twice. (Original) 



