222 NEBRASKA STATE HORTICULTURAL SOCIETY 



Summary of Experiments 



The plum curculio and the codling moth are the most destructive 

 insects to the apple crop in jMissouri and the mid-west. The financial 

 loss from these two pests in a year when an average crop is bourne 

 amounts to millions of dollars. 



The plum curculio is the small, grayish, snout-beetle well known to 

 orchardists, which injures the apple by making small round holes 

 through the skin in feeding and by making the half-moon shaped marks 

 upon the surface of the fruit in egg-laying. There is but a single annual 

 generation. They hibernate in the winter as adult beetles and appear 

 in the orchard shortly after the blooming of the fruit. Sometimes the 

 beetles feed sparingly upon the foliage, eating small holes from the 

 leaves. From the time apples measure one-third of an inch in diameter 

 to when they reach the size of walnuts the maximum number of both 

 food and egg punctures are being made. If not destroyed early in the 

 season the beetles will continue to puncture the fruit and to produce a 

 new generation. Apples punctured by curculio may fall to the ground 

 as windfalls or if left upon the tree may be so badly stung, gnarled and 

 deformed as to be unfit for market. 



The codling moth is the parent of the "apple worm." It and its 

 work, the "wormy apple," are already too familiar to orchardists. Fruit 

 growers should know when each transformation of the insect takes place 

 throughout the year. Apple growers spray against both curculio and 

 codling moth, modifying their scheme of treatment for the fungous 

 diseases which have also to be combatted. 



A practical spraying experiment was conducted in 1909 upon a block 

 of about twenty acres of Ingram apples in a large commercial Ozark apple 

 orchard for the purposes of showing the best kind of spray, the proper 

 time to spray and the best way to spray apples to prevent codling moth 

 and curculio injury. Three early sprays resulted in 97.6 per cent picked 

 apples free from curculio crescents while 45.5 per cent were damaged on 

 the trees unsprayed. Three early sprays resulted in 99.83 per cent 

 picked apples free from codling moth worm holes, 14.5 per cent being 

 wormy from codling moth on the trees unsprayed. There were 97.4 per 

 cent picked apples free from both kinds of injuries when sprayed three 

 times while unsprayed trees gave only 46.1 per cent free from such 

 blemishes. The three early sprays, by preventing windfalls, gave 45 

 per cent more picked apples than the unsprayed trees. When the fruit 

 from the sprayed and unsprayed parts of the orchard was graded, in- 

 juries from both insects and fungi being considered, and sold it was 

 found that the spraying had doubled the cash returns from the crop. 

 After deducting the cost of spraying a net profit by virtue of the sprays 

 amounting to $65.36 per acre, was secured. For every dollar expended 

 for spraying $7 were saved in the price secured for the fruit. The pro- 

 fits accruing, though yield of trees was light, was sufficient upon a twen- 

 ty-acre tract to pay in one year for a $300 gasoline power spray outfit and 

 leave more than a thousandd dollars clear gain besides. 



