April 1921 



in the course of a day or so, they eat 

 into the tips until they are concealed 

 and protected. Here they eat not only 

 the tender tips but also burrow into 

 the pith of the small twigs, causing 

 the leaves to wilt and die. In the spring 

 when wilted twigs may be easily no- 

 ticed, the work of the twig-borer is 

 more evident than at any other time 

 of the year. A single larvae may go 

 from one twig to another and the in- 

 jury caused by only a few of them may 

 be great. 



Number of Broods Annually 



THERE are probably not more than 

 two broods annually in Idaho and 

 in the higher altitudes but a partial 

 second brood. As already mentioned, 

 the first brood attacks the foliage, but 

 larvae of the second brood bore into the 

 fruit, usually through the stem end, 

 and feed freely on the fruit or inside 

 the pit. The appearance of wormy 

 peaches and prunes is too familiar to 

 most orchardists to need description 

 and a very large proportion of the gum- 

 my peaches and prunes which are a 

 source of no small annoyance to pack- 

 ers and loss to growers are the result 

 of injury caused by larvae of the twig- 

 borer. Losses of as great as twenty- 

 five per cent have been reported, but 

 it is a significant fact that little or no 

 loss occurs in orchards which are regu- 

 larly sprayed with the dormant spray 

 of lime sulphur. 



Appearance of the Twig-Borer 



WHEN fully grown, the larva is 

 about three-eighths of an inch 

 long, of whitish yellow or pink color 

 and sparsely covered with fine, bristle- 

 like hairs. The fore part of the body 

 and the head are brown or almost black. 



After the larva has become fully 

 grown, it changes to the pupa, in which 

 stage it remains for two or three weeks. 

 The pupa is enclosed by a few threads 

 of fine silk. The first brood passes the 

 pupal utage in cracks or rough places 

 in the bark, between fruits which touch 

 each other and among trash and vege- 

 tation on the ground. The later brood 

 is believed to pupate mostly in the de- 

 pressions at the stem-ends of the fruits. 



The adult of the peach and prune 

 twig-borer is a small, gray moth about 

 one-fourth inch in length and one-half 

 inch from tip to tip of outstretched 

 wings. Botli front and hind wings have 

 a fringed border. Moths are not easily 

 observed and are rarely recognized by 

 orchardists. Eggs of the first brood of 

 moths are laid on leaf stems but those 

 of the second brood are laid in the scem- 

 end depressions of fruits and in crev- 

 ices of bark between crotches. When 

 first laid they are nearly white but be- 

 fore hatching change to yellow. 



BETTER FRUIT 



Page 9 



TOP-DRESSING TALK No. 5 



Fertilizing for the Cover Crop 



An early application of Arcadian Sulphate of Ammonia to the 

 orchard will stimulate fruit bud formation, increase the amount of 

 fruit set and enable the tree to carry a full crop of fruit to maturity. 



In addition, the nitrogen and the sulphur will greatly increase the 

 growth of the cover crop, which if plowed under, will build up the 

 organic matter content of the soil. 



The picture above shows the beneficial effect of this fertilizer on a 

 cover crop of sweet clover. 



Arcadian Sulphate of Ammonia 



Arcadian is the ideal orchard fertilizer. It is fine and dry and can be distributed 

 easily and uniformly by hand or machine. Being a non-leaching form of nitrogen 

 it can be applied early in the spring without undue loss from washing by spring 

 rains. 



Sulphate of Ammonia is the well-known standard article that has done you good 

 service in your mixed fertilizers for years past. 



Arcadian is the kiln-dried and screened grade, made fine and dry for top-dress- 

 ing purposes. Ammonia 2514% guaranteed. Mlade in U. S. A. 



Write Desk No. 9 for Free Bulletins. No. 8. "The 

 Use of Sulphate of Ammonia in the Fertilization of 

 Peaches" and No. 85. "Fertilizing the Apple Orchard" 



FOR SALE BY 



CALIFORNIA: San Fr 



Fer 



;o., Pacific Bone, Coal & Fertilizing Co.. Pacific 

 "Western Meat Co , California Fertilizer Works. Los Angeles; Pacific Guano & 



- - n SL~; G ~ -R n -, r^at <L- Fertilizing Co Agricultural Chemical Works. Hauser Packing Co., 



■" F°VtiHz«r Cc I ltd Smithe™ CaWorni'a Fertilizer Co. OREGON: Portland; Swift & Co. 



For information 

 as to application, 

 write Desk No. 9 



Company 



Agricultural 

 Department 



510 First National Bank Building, Berkeley, California 



