50 THE MONTHLY BULLETIN. 



CALENDAR OF INSECT PESTS AND 

 PLANT DISEASES. 



By E. J. VOSLEE. 



[Under the above heading the author aims to give brief, popular descriptions and 

 methods of controlling insect pests and plant diseases as nearly as possible just prior 

 to or at the time when the suggestions given should be carried into effect by the 

 grovs'ers. ] 



DECIDUOUS FRUIT INSECTS. 



The Peach Twigf Borer. 



One of the most destructive insects attacking the peach is the peach 

 twig borer. The larvie of the peach twig borer burrow into the young 

 buds and tender shoots, and later on enter the fruit at the stem end, 

 often completely encircling the pit and rendering the fruit unsalable as 

 a first class product. 



The peach is the principal host of this insect. The larvse vary in 

 color from a dusky white to dark brown, the head and the first three 

 body segments being black. They are rarely over one half inch in 

 length, after becoming full grown. 



The life history of the peach twig borer is as follows : The moths, 

 which emerge often before the last of July, give rise to the very young 

 larvae which make minute burrows in the bark, located principally 

 in the crotches of the limbs. These burrows are found by the tiny 

 silken tubes made of chewed bark, projecting upward above the burrows. 

 The small larvae pass the winter in these burrows and come out in the 

 early spring to feed on the tender shoots and starting buds. Almost 

 everyone has seen the drooping young shoots, and on examining these 

 has found the worms which do the damage. Some become full grown 

 about May, passing the resting stage in the crevices in the bark of the 

 trees. The adults emerge about a week after pupation. 



The use of a commercial preparation of lime-sulphur, diluted 1 to 10, 

 when the blossoms are just opening, gives excellent results. The com- 

 mercial lime sulphur can be obtained from the various insecticide 

 dealers. If the lime-sulphur solution is used at the time indicated 

 above, it will be unnecessary to make another spray for peach leaf curl, 

 as this spray will control both the peach twig borer and the disease. 



Spraying for the Eggs of the Walnut Aphis. 



The walnut Aphis has caused a considerable amount of injury to the 

 walnut in this state. The aphids are small, lemon yellow, sucking 

 insects, and are about 1/16 inch in length. They are generally found 

 on the undersides of the leaves, and on the young walnuts, sucking out 

 the juices of the host. 



The aphids are present, according to Davidson, from February until 

 December, occurring in greatest numbers during the months of July 

 and August. There may be from six to ten generations a year. Some- 

 times the infestation is so great that a single leaflet may harbor over a 

 hundred and fifty individuals, and Davidson has counted over three 

 hundred aphids on a single young nut. 



If the nuts become ])adly infested while young, they are stunted and 

 do not reach their natural size. These infested walnuts mav be about 



