74 



whale-oil soap (2 pounds in a gallon of water), (ir crude petroleum, the pruning 

 should be done first and the cut branches gathered up and piled where the spray 

 can not reach them. 



This is done to preserve tlie little friends nature has sui^plied to help keep the scale 

 in check. If the twigs and branches are burned or sprayed the parasites would be 

 destroyed, as they feed upon the scale insects and are now wintering under the shell- 

 like cover protecting them. These parasites are very small, being scarcely visible 

 to the naked eye, yet they play an important part in the economy of nature. They 

 are wasp-like in general appearance and quite active. It would be very difficult to 

 estimate the actual number of parasites present upon a 5 or 6 year old peach or 

 plum tree, but it is safe to say that they would run into the millions if the para- 

 sitism was at same rate as upon the twigs in the tubes. 



If I had burned these twigs I would have destroyed all the parasites. On the other 

 hand, if I had left them on the ground in the orchard the little friends would have 

 escaped and concentrated their attacks upon other trees where the scale had been 

 missed by the sprays. It is clear, then, that by using a little judgment in these 

 matters we can assist nature in restoring the balance she desires. Do not sit down 

 and fold your arms thinking nature is going to restore this equilibrium at once; 

 you must do your part faithfully and well. Prune your orchard as soon as possible 

 and save every twig that contains a scale; then spray with a 25 per cent solution of 

 kerosene and water, using any first-class spray pump, or with whale-oil soap (2 

 pounds to a gallon of water), before the buds open. 



There is no possil)ility of the scale spreading until some time after the 1st of June. 

 The young begin to apjjear in the vicinity of Washington, D. C, June 10 to 15 [in 

 1900 young were seen by the writer crawling June 3 near Washington] , and the insect 

 continues to breed until very cold weather. We have seen young, just born, on trees 

 as late as December 19. When a twig is cut off between, say, December 20 and May 

 15, there is no possible danger of the scale spreading from it. It is not possible to 

 transfer one of these insects from one twig to another after it is " set ' ' and formed a 

 scale over its back, and all of them die as soon as the sap is dried out of a cut twig 

 or branch. Badly infested trees of no commercial value should be cut down now as 

 soon as possible, before the buds open, and the brush piled. Do not leave the stump 

 standing, as it may prove a veritable breeding place during the summer. If you are 

 so unfortunate as to have this scale, remember that eternal vigilance nnust be the 

 order of the day, and you will find before you are through with it that it is no 

 trifling matter. 



The orchard in question was not destroyed by burning, as first sug- 

 gested, but the trees were pruned and the cuttings saved. In May, 

 1900, the writer had a large quantity of the branches from this orchard 

 carefully packed and sent to Mr. W. W. Cobey, Grayson, Charles 

 County; to Capt. R. S. Emory, Chestertown, Kent County, and to 

 Hon. Charles G. Biggs, Sharpsburg, Washington County. Instruc- 

 tions were sent to place the infested branches in grape baskets and 

 hang them about the orchard where the scale was most abundant. In 

 this manner we will establish Aj)helinus fuscijyenrds in the various 

 counties and under different conditions. We have every reason to 

 believe that the experiment will prove successful. 



In this case the study of parasitism has given us a valuable sugges- 

 tion for the treatment of scale infested orchards, namel}^, never burn 

 a twig or tree cut late in the fall, winter, or early spring. A positive 



