SCIENCE'S WARFARE ON FRUIT TREE PESTS 223 



A spray of the standard Bordeaux mixture just before blooming, in 

 addition to the sprays after blooming, will be necessary to prevent apple 

 scab. 



After the petals fall, but before the calyx cups close, apply a drench- 

 ing spray of arsenate of lead, using two pounds to fifty gallons. This 

 is the first curculio and codling moth spray, and is the most important of 

 all sprays used against the codling moth. Every calyx cup should be 

 filled to the brim. In ten days to two weeks after this apply a mist spray 

 of arsenate of lead with a weak Bordeaux mixture. This should be to 

 coat the little apples and the leaves. It will be before the codling moth 

 eggs are laid but will be when many curculios are feeding. In ten days 

 or two weeks following apply another mist spray of arsenate of lead with 

 weak Bordeaux mixture, coating over apples and leaves. This will be 

 when curculios are abundant. Apples wil measure three-fourths to one 

 and a half inches in diameter, 



In orchards where codling moth damage has been very severe and 

 curculio injury light, the spray, given ten days or two weeks after petals 

 fall, should be omitted and the third sprays applied about six weeks after 

 the petals fall. The maximum number of codling moth worms are then 

 entering. Three early sprays, as recommended, if thoroughly applied, 

 will be sufficient to control both codling moth and curculio under aver- 

 age conditions in the middle-west. 



A guaranteed brand of arsenate of lead is the best insecticide for 

 apple spraying. Homemade arsenate of lead is preferred by some grow- 

 ers. Paris green is not quite as effective as arsenate of lead, and though 

 iised with every precaution often damages the apples by causing black- 

 ened areas about the blossom end. In the long run arsenate of lead is 

 the cheaper spray. 



Thoroughness of spraying is the greatest essential. The spray given 

 after the petals fall should be through a coarse nozzle at a high pressure 

 and the liquid shot squarely into the calyx cups. Later sprays should be 

 given as a mist, but should coat every apple and leaf with poison. 

 Whether the spray outfit be a barrel pump or a gasoline power outfit, buy 

 only the best. Good spraying can only be done with good spray outfits 

 and enough of them on each orchard to complete the spraying at the 

 proper time. 



Spraying is the principal operation in controlling codling moth and 

 curculio in apple orchards. There are other operations, such as mid- 

 summer cultivation, destruction of windfalls, thinning of wormy fruit, 

 etc., which have an important influence. 



Plant Lice and Their Remedies 



The following information is condensed from Bulletin No. 134, 

 issued by the Colorado State Fruit Experiment station, and is the joint 

 work of Prof. C. P. Gillette of the Colorado station, and Professor Taylor 

 of the Missouri station. 



The plant lice that are commonly designated as "aphids" have very 



