Page 44 



BETTER FRUIT 



May 



sickly appearance when compared with 

 perfectly healthy trees. Even if the tree 

 does survive and bear a certain amount 

 of fruit the work of the borer weakens 

 the tree more or less, the damage done 

 depending much upon the age of the tree 

 and whether it has received proper care. 



The work of the borer always causes 

 the tree to exude a large amount of a 

 mucilaginous substance, which forms a 

 gummy mass around the infested por- 

 tion, this mass often being visible on the 

 surface of the soil, about the base of the 

 tree. On plum and prune trees there is 

 very little of the exudation, thus making 

 is more difficult to find the borers and 

 harder to combat them in these trees. 



The peach tree borer undergoes a 

 complete metamorphosis in its life his- 

 tory, passing through the four stages — 

 egg, "borer"' or larva, pupa and the adult 

 or moth. 



The borer always passes the winter in 

 the larval stage. In the South they are 

 nearly full grown before hibernating, 

 while in the North they are quite small 

 at the time of hibernation, some being 

 little more than half grown. However, 

 in most localities it is possible to find 

 borers of all sizes in the trees during the 

 winter. It has been found that most of 

 the full grown borers pass the winter in 

 their burrows underneath the bark, while 

 the borers that are less than half grown 

 pass the winter curled up in a thin 

 half cocoon-like structure, usually at the 

 upper end of their burrows, which are 

 between the outer and inner surface of 

 the bark. 



This peculiar method of hibernation of 

 the smaller borers is of considerable 

 importance economically, as several of 

 the Northern peach growers have dis- 

 covered that they can quickly remove 

 most of the borers a safe distance from 

 the trees during a warm spell in winter 

 by simply hoeing away the exuded gum 

 from around the base of the trees. 



The peach tree borer apparently does 

 not feed during the winter, at least such 

 ,is the case in the Northern states. 



In the latter part of April or early in 

 May the borers awake from their win- 

 ter's nap and begin feeding on the bark 

 of the tree. Climatic conditions influ- 

 ence the time of beginning work to a 

 gre*at extent. The older borers usually 

 begin work in their burrows where they 

 left ofif in the fall, while the younger 

 ones, which have hibernated in the outer 

 bark, begin feeding there; however, they 

 soon burrow deeper into the bark until 

 the wood is reached, where they exca- 

 vate, partly in the wood and partly in 

 the bark, a burrow varying from one- 

 half to an inch or more in width and 

 from two to several inches long. 



Occasionally a borer may be found in 

 the trunk of the tree above ground, and 

 even in the root six or more inches 

 underground, but most entomologists 

 agree that the most destructive work 

 occurs on the trunk or roots about the 

 surface or at a short distance below 

 the ground. 



The borers do the greatest damage 

 during the season of the year in which 

 they make their greatest growth. In the 

 South this occurs in the late summer and 



fall, for most of them pass the winter as 

 full grown borers, but in the North the 

 season of greatest growth is in May, 

 June and July. It is surprising how 

 rapidly the smaller borers grow in the 

 spring. In experiments at Cornell it was 

 found that borers, only one-fourth inch 

 long on April 19th, grew so rapidly that 

 in ninety days, or by July 20th, had not 

 only grown into caterpillars an inch long, 

 but had spun cocoons, transformed into 

 pupae and the adult insect or moth had 

 emerged. 



MOTHS OF PEACH BORER 

 (After Slingerland. Bulletin No. 176, Cornell 

 Experiment Station) 



When full grown the borer leaves its 

 burrow under the bark and proceeds to 

 make around itself the cocoon. This is 

 a rough, brown, elongated oval capsule 

 with slightly pointed ends, and is about 

 an inch in length. It is constructed by 

 the borer of its excrements and particles 

 of bark, these being bound together with 

 gum and a thin smooth inner lining of 

 silk. It takes the borer from two to 

 three days to complete its cocoon. The 

 cocoons are usually attached to the out- 

 side of the bark of the tree at or near 

 the surface of the soil, but occasionally 

 one is found two or three inches below 

 the surface or lying loosely in the soil. 

 The borer spends from three to five days 

 making its cocoon, then sheds its skin 

 and transforms into the pupa. 



Pupa is the third stage into which the 

 peach tree borer is transformed. It is 

 of a dark brown color, considerably 

 lighter when first formed and measures 

 about three-fourths of an inch in length. 

 The male and female pupae are readily 

 distinguished; the female is larger and 

 more robust, and it has but one row of 

 spines across the back of the seventh 

 abdominal segment, while there are two 

 rows of these spines on this segment of 

 the male pupa. The pupal stage is the 

 resting stage, and is where the change 

 from the larva to the adult stage takes 

 place. The pupa is not capable of mov- 

 ing about, but moves the abdomen 

 slightly when disturbed. No feeding 

 takes place in this stage. According to 

 all printed reports the pupal stage lasts 

 for about twenty-one days. 



When the pupa is fully mature, or 

 when the adult insect is ready to emerge, 

 the pupa uses the hard, sharp, beak-like 

 prominence on its head to break through 

 the end of the cocoon, and then by 

 means of the rows of spines on its back 

 it moves or hitches itself forward until 

 it projects for half its length or more 

 out of the cocoon. This movement of 

 the pupa out of the cocoon and the wise 

 precaution of the borer to build its 

 cocoon near the surface of the soil usu- 

 ally results in bringing the projecting 

 pupa out of the soil. Thus the adult 

 insect or moth, which is- delicate and soft 

 when it first emerges, finds itself at once 

 in its favorite element— the open air. 



The moth bursts through the pupa 

 skin, which splits down the center of the 

 back for a short distance. After care- 

 fully drawing out its wings, legs, anten- 

 nae and tongue from their pupal sheaths 

 it may crawl a short distance, where it 

 rests for from twenty minutes to half an 

 hour to let its wings expand and dry. 

 It is then ready for active flight. 



The adults are most active during the 

 day, and fly but little, if any, at night. 

 One who is familiar with them may, by 

 close observation, see them flying about 

 in the orchard during the summer 

 months. No data is given to show 

 exactly how long the moth lives, but it 

 is probably not more than a week, the 

 female moth probably living just long 

 enough to mate and deposit her quota 

 of eggs. 



One female is capable of laying from 

 200 to 600 eggs, which are scattered over 

 the trunk of the tree, the larger number 

 within six inches of the soil and a few 

 as high as eighteen inches above the sur- 

 face of the soil, no attention being given 

 to placing them in protected positions. 

 They have been found singly and in 

 groups of nine or ten. The eggs are 

 of a light chestnut color, somewhat 

 elliptical in form, and are slightly flat- 

 tened. They average about .02 of an 

 inch in length and a little more than 

 half as wide. 



Probably most of the eggs are laid in 

 July and August in the Northern states. 

 From these eggs there hatches, in a 

 week or ten days, minute larvae, the 

 young borers, which at once work their 

 way into crevices of the bark, and soon 

 begin feeding on the inner layers. A 

 minutely small crack will suffice for the 

 entrance of the borer, which fact has a 

 very important bearing on the question 

 of preventive applications for the pest. 



At least eight different enemies of the 

 peach tree borer have been found, which, 

 in some localities, may play an important 

 part in the control of the insect. 



Although American peach growers 

 have been fighting the peach borer for a 

 hundred and fifty years the results from 

 present day methods of warfare are not 

 strikingly different from those recorded 

 in 1806. Most of the applications now 

 recommended were devised nearly a 

 century ago. 



Cultural methods have no direct effect 

 on the borers unless it be to cultivate 

 and fertilize the trees so that they will 

 outgrow their injury. It is certainly 



